Commit Graph

2145 Commits

Author SHA1 Message Date
Mark Rutland
eccc2da8c0 atomics/treewide: Make atomic_fetch_add_unless() optional
Several architectures these have a near-identical implementation based
on atomic_read() and atomic_cmpxchg() which we can instead define in
<linux/atomic.h>, so let's do so, using something close to the existing
x86 implementation with try_cmpxchg().

Where an architecture provides its own atomic_fetch_add_unless(), it
must define a preprocessor symbol for it. The instrumented atomics are
updated accordingly.

Note that arch/arc's existing atomic_fetch_add_unless() had redundant
barriers, as these are already present in its atomic_cmpxchg()
implementation.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Link: https://lore.kernel.org/lkml/20180621121321.4761-7-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 14:22:33 +02:00
Mark Rutland
bef828204a atomics/treewide: Make atomic64_inc_not_zero() optional
We define a trivial fallback for atomic_inc_not_zero(), but don't do
the same for atomic64_inc_not_zero(), leading most architectures to
define the same boilerplate.

Let's add a fallback in <linux/atomic.h>, and remove the redundant
implementations. Note that atomic64_add_unless() is always defined in
<linux/atomic.h>, and promotes its arguments to the requisite types, so
we need not do this explicitly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-6-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 14:22:33 +02:00
Mark Rutland
bfc18e389c atomics/treewide: Rename __atomic_add_unless() => atomic_fetch_add_unless()
While __atomic_add_unless() was originally intended as a building-block
for atomic_add_unless(), it's now used in a number of places around the
kernel. It's the only common atomic operation named __atomic*(), rather
than atomic_*(), and for consistency it would be better named
atomic_fetch_add_unless().

This lack of consistency is slightly confusing, and gets in the way of
scripting atomics. Given that, let's clean things up and promote it to
an official part of the atomics API, in the form of
atomic_fetch_add_unless().

This patch converts definitions and invocations over to the new name,
including the instrumented version, using the following script:

  ----
  git grep -w __atomic_add_unless | while read line; do
  sed -i '{s/\<__atomic_add_unless\>/atomic_fetch_add_unless/}' "${line%%:*}";
  done
  git grep -w __arch_atomic_add_unless | while read line; do
  sed -i '{s/\<__arch_atomic_add_unless\>/arch_atomic_fetch_add_unless/}' "${line%%:*}";
  done
  ----

Note that we do not have atomic{64,_long}_fetch_add_unless(), which will
be introduced by later patches.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-2-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 14:22:32 +02:00
Will Deacon
356c6fe7d8 locking/atomics/arm64, arm64/bitops: Include <asm-generic/bitops/ext2-atomic-setbit.h>
<asm-generic/bitops/ext2-atomic-setbit.h> provides the ext2 atomic bitop
definitions, so we don't need to define our own.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: yamada.masahiro@socionext.com
Link: https://lore.kernel.org/lkml/1529412794-17720-10-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 12:52:12 +02:00
Will Deacon
7c8fc35dfc locking/atomics/arm64: Replace our atomic/lock bitop implementations with asm-generic
The <asm-generic/bitops/{atomic,lock}.h> implementations are built around
the atomic-fetch ops, which we implement efficiently for both LSE and
LL/SC systems. Use that instead of our hand-rolled, out-of-line bitops.S.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: yamada.masahiro@socionext.com
Link: https://lore.kernel.org/lkml/1529412794-17720-9-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 12:52:12 +02:00
Masami Hiramatsu
2efb75cd71 arm64/kprobes: Remove jprobe implementation
Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/arm64.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/lkml/152942442318.15209.17767976282305601884.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 12:33:07 +02:00
Dave Martin
b3eb56b629 KVM: arm64/sve: Fix SVE trap restoration for non-current tasks
Commit e6b673b ("KVM: arm64: Optimise FPSIMD handling to reduce
guest/host thrashing") attempts to restore the configuration of
userspace SVE trapping via a call to fpsimd_bind_task_to_cpu(), but
the logic for determining when to do this is not correct.

The patch makes the errnoenous assumption that the only task that
may try to enter userspace with the currently loaded FPSIMD/SVE
register content is current.  This may not be the case however:  if
some other user task T is scheduled on the CPU during the execution
of the KVM run loop, and the vcpu does not try to use the registers
in the meantime, then T's state may be left there intact.  If T
happens to be the next task to enter userspace on this CPU then the
hooks for reloading the register state and configuring traps will
be skipped.

(Also, current never has SVE state at this point anyway and should
always have the trap enabled, as a side-effect of the ioctl()
syscall needed to reach the KVM run loop in the first place.)

This patch instead restores the state of the EL0 trap from the
state observed at the most recent vcpu_load(), ensuring that the
trap is set correctly for the loaded context (if any).

Fixes: e6b673b741 ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-06-21 09:14:44 +01:00
Mark Rutland
6ebdf4db8f arm64: Introduce sysreg_clear_set()
Currently we have a couple of helpers to manipulate bits in particular
sysregs:

 * config_sctlr_el1(u32 clear, u32 set)

 * change_cpacr(u64 val, u64 mask)

The parameters of these differ in naming convention, order, and size,
which is unfortunate. They also differ slightly in behaviour, as
change_cpacr() skips the sysreg write if the bits are unchanged, which
is a useful optimization when sysreg writes are expensive.

Before we gain yet another sysreg manipulation function, let's
unify these with a common helper, providing a consistent order for
clear/set operands, and the write skipping behaviour from
change_cpacr(). Code will be migrated to the new helper in subsequent
patches.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-06-21 09:14:54 +01:00
Mauro Carvalho Chehab
5fb94e9ca3 docs: Fix some broken references
As we move stuff around, some doc references are broken. Fix some of
them via this script:
	./scripts/documentation-file-ref-check --fix

Manually checked if the produced result is valid, removing a few
false-positives.

Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-06-15 18:10:01 -03:00
Linus Torvalds
b357bf6023 Small update for KVM.
* ARM: lazy context-switching of FPSIMD registers on arm64, "split"
 regions for vGIC redistributor
 
 * s390: cleanups for nested, clock handling, crypto, storage keys and
 control register bits
 
 * x86: many bugfixes, implement more Hyper-V super powers,
 implement lapic_timer_advance_ns even when the LAPIC timer
 is emulated using the processor's VMX preemption timer.  Two
 security-related bugfixes at the top of the branch.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "Small update for KVM:

  ARM:
   - lazy context-switching of FPSIMD registers on arm64
   - "split" regions for vGIC redistributor

  s390:
   - cleanups for nested
   - clock handling
   - crypto
   - storage keys
   - control register bits

  x86:
   - many bugfixes
   - implement more Hyper-V super powers
   - implement lapic_timer_advance_ns even when the LAPIC timer is
     emulated using the processor's VMX preemption timer.
   - two security-related bugfixes at the top of the branch"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (79 commits)
  kvm: fix typo in flag name
  kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access
  KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system
  KVM: x86: introduce linear_{read,write}_system
  kvm: nVMX: Enforce cpl=0 for VMX instructions
  kvm: nVMX: Add support for "VMWRITE to any supported field"
  kvm: nVMX: Restrict VMX capability MSR changes
  KVM: VMX: Optimize tscdeadline timer latency
  KVM: docs: nVMX: Remove known limitations as they do not exist now
  KVM: docs: mmu: KVM support exposing SLAT to guests
  kvm: no need to check return value of debugfs_create functions
  kvm: Make VM ioctl do valloc for some archs
  kvm: Change return type to vm_fault_t
  KVM: docs: mmu: Fix link to NPT presentation from KVM Forum 2008
  kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation
  KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capability
  KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX implementation
  KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation
  KVM: introduce kvm_make_vcpus_request_mask() API
  KVM: x86: hyperv: do rep check for each hypercall separately
  ...
2018-06-12 11:34:04 -07:00
Linus Torvalds
410feb75de arm64 updates for 4.18:
- Spectre v4 mitigation (Speculative Store Bypass Disable) support for
   arm64 using SMC firmware call to set a hardware chicken bit
 
 - ACPI PPTT (Processor Properties Topology Table) parsing support and
   enable the feature for arm64
 
 - Report signal frame size to user via auxv (AT_MINSIGSTKSZ). The
   primary motivation is Scalable Vector Extensions which requires more
   space on the signal frame than the currently defined MINSIGSTKSZ
 
 - ARM perf patches: allow building arm-cci as module, demote dev_warn()
   to dev_dbg() in arm-ccn event_init(), miscellaneous cleanups
 
 - cmpwait() WFE optimisation to avoid some spurious wakeups
 
 - L1_CACHE_BYTES reverted back to 64 (for performance reasons that have
   to do with some network allocations) while keeping ARCH_DMA_MINALIGN
   to 128. cache_line_size() returns the actual hardware Cache Writeback
   Granule
 
 - Turn LSE atomics on by default in Kconfig
 
 - Kernel fault reporting tidying
 
 - Some #include and miscellaneous cleanups
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "Apart from the core arm64 and perf changes, the Spectre v4 mitigation
  touches the arm KVM code and the ACPI PPTT support touches drivers/
  (acpi and cacheinfo). I should have the maintainers' acks in place.

  Summary:

   - Spectre v4 mitigation (Speculative Store Bypass Disable) support
     for arm64 using SMC firmware call to set a hardware chicken bit

   - ACPI PPTT (Processor Properties Topology Table) parsing support and
     enable the feature for arm64

   - Report signal frame size to user via auxv (AT_MINSIGSTKSZ). The
     primary motivation is Scalable Vector Extensions which requires
     more space on the signal frame than the currently defined
     MINSIGSTKSZ

   - ARM perf patches: allow building arm-cci as module, demote
     dev_warn() to dev_dbg() in arm-ccn event_init(), miscellaneous
     cleanups

   - cmpwait() WFE optimisation to avoid some spurious wakeups

   - L1_CACHE_BYTES reverted back to 64 (for performance reasons that
     have to do with some network allocations) while keeping
     ARCH_DMA_MINALIGN to 128. cache_line_size() returns the actual
     hardware Cache Writeback Granule

   - Turn LSE atomics on by default in Kconfig

   - Kernel fault reporting tidying

   - Some #include and miscellaneous cleanups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (53 commits)
  arm64: Fix syscall restarting around signal suppressed by tracer
  arm64: topology: Avoid checking numa mask for scheduler MC selection
  ACPI / PPTT: fix build when CONFIG_ACPI_PPTT is not enabled
  arm64: cpu_errata: include required headers
  arm64: KVM: Move VCPU_WORKAROUND_2_FLAG macros to the top of the file
  arm64: signal: Report signal frame size to userspace via auxv
  arm64/sve: Thin out initialisation sanity-checks for sve_max_vl
  arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_ID
  arm64: KVM: Handle guest's ARCH_WORKAROUND_2 requests
  arm64: KVM: Add ARCH_WORKAROUND_2 support for guests
  arm64: KVM: Add HYP per-cpu accessors
  arm64: ssbd: Add prctl interface for per-thread mitigation
  arm64: ssbd: Introduce thread flag to control userspace mitigation
  arm64: ssbd: Restore mitigation status on CPU resume
  arm64: ssbd: Skip apply_ssbd if not using dynamic mitigation
  arm64: ssbd: Add global mitigation state accessor
  arm64: Add 'ssbd' command-line option
  arm64: Add ARCH_WORKAROUND_2 probing
  arm64: Add per-cpu infrastructure to call ARCH_WORKAROUND_2
  arm64: Call ARCH_WORKAROUND_2 on transitions between EL0 and EL1
  ...
2018-06-08 11:10:58 -07:00
Laurent Dufour
3010a5ea66 mm: introduce ARCH_HAS_PTE_SPECIAL
Currently the PTE special supports is turned on in per architecture
header files.  Most of the time, it is defined in
arch/*/include/asm/pgtable.h depending or not on some other per
architecture static definition.

This patch introduce a new configuration variable to manage this
directly in the Kconfig files.  It would later replace
__HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.com
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:35 -07:00
Linus Torvalds
ba252f16e4 Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull time/Y2038 updates from Thomas Gleixner:

 - Consolidate SySV IPC UAPI headers

 - Convert SySV IPC to the new COMPAT_32BIT_TIME mechanism

 - Cleanup the core interfaces and standardize on the ktime_get_* naming
   convention.

 - Convert the X86 platform ops to timespec64

 - Remove the ugly temporary timespec64 hack

* 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  x86: Convert x86_platform_ops to timespec64
  timekeeping: Add more coarse clocktai/boottime interfaces
  timekeeping: Add ktime_get_coarse_with_offset
  timekeeping: Standardize on ktime_get_*() naming
  timekeeping: Clean up ktime_get_real_ts64
  timekeeping: Remove timespec64 hack
  y2038: ipc: Redirect ipc(SEMTIMEDOP, ...) to compat_ksys_semtimedop
  y2038: ipc: Enable COMPAT_32BIT_TIME
  y2038: ipc: Use __kernel_timespec
  y2038: ipc: Report long times to user space
  y2038: ipc: Use ktime_get_real_seconds consistently
  y2038: xtensa: Extend sysvipc data structures
  y2038: powerpc: Extend sysvipc data structures
  y2038: sparc: Extend sysvipc data structures
  y2038: parisc: Extend sysvipc data structures
  y2038: mips: Extend sysvipc data structures
  y2038: arm64: Extend sysvipc compat data structures
  y2038: s390: Remove unneeded ipc uapi header files
  y2038: ia64: Remove unneeded ipc uapi header files
  y2038: alpha: Remove unneeded ipc uapi header files
  ...
2018-06-04 21:02:18 -07:00
Linus Torvalds
0bbcce5d1e Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timers and timekeeping updates from Thomas Gleixner:

 - Core infrastucture work for Y2038 to address the COMPAT interfaces:

     + Add a new Y2038 safe __kernel_timespec and use it in the core
       code

     + Introduce config switches which allow to control the various
       compat mechanisms

     + Use the new config switch in the posix timer code to control the
       32bit compat syscall implementation.

 - Prevent bogus selection of CPU local clocksources which causes an
   endless reselection loop

 - Remove the extra kthread in the clocksource code which has no value
   and just adds another level of indirection

 - The usual bunch of trivial updates, cleanups and fixlets all over the
   place

 - More SPDX conversions

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  clocksource/drivers/mxs_timer: Switch to SPDX identifier
  clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier
  clocksource/drivers/timer-imx-gpt: Switch to SPDX identifier
  clocksource/drivers/timer-imx-gpt: Remove outdated file path
  clocksource/drivers/arc_timer: Add comments about locking while read GFRC
  clocksource/drivers/mips-gic-timer: Add pr_fmt and reword pr_* messages
  clocksource/drivers/sprd: Fix Kconfig dependency
  clocksource: Move inline keyword to the beginning of function declarations
  timer_list: Remove unused function pointer typedef
  timers: Adjust a kernel-doc comment
  tick: Prefer a lower rating device only if it's CPU local device
  clocksource: Remove kthread
  time: Change nanosleep to safe __kernel_* types
  time: Change types to new y2038 safe __kernel_* types
  time: Fix get_timespec64() for y2038 safe compat interfaces
  time: Add new y2038 safe __kernel_timespec
  posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME
  time: Introduce CONFIG_COMPAT_32BIT_TIME
  time: Introduce CONFIG_64BIT_TIME in architectures
  compat: Enable compat_get/put_timespec64 always
  ...
2018-06-04 20:27:54 -07:00
Linus Torvalds
92400b8c8b Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:

 - Lots of tidying up changes all across the map for Linux's formal
   memory/locking-model tooling, by Alan Stern, Akira Yokosawa, Andrea
   Parri, Paul E. McKenney and SeongJae Park.

   Notable changes beyond an overall update in the tooling itself is the
   tidying up of spin_is_locked() semantics, which spills over into the
   kernel proper as well.

 - qspinlock improvements: the locking algorithm now guarantees forward
   progress whereas the previous implementation in mainline could starve
   threads indefinitely in cmpxchg() loops. Also other related cleanups
   to the qspinlock code (Will Deacon)

 - misc smaller improvements, cleanups and fixes all across the locking
   subsystem

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
  locking/rwsem: Simplify the is-owner-spinnable checks
  tools/memory-model: Add reference for 'Simplifying ARM concurrency'
  tools/memory-model: Update ASPLOS information
  MAINTAINERS, tools/memory-model: Update e-mail address for Andrea Parri
  tools/memory-model: Fix coding style in 'lock.cat'
  tools/memory-model: Remove out-of-date comments and code from lock.cat
  tools/memory-model: Improve mixed-access checking in lock.cat
  tools/memory-model: Improve comments in lock.cat
  tools/memory-model: Remove duplicated code from lock.cat
  tools/memory-model: Flag "cumulativity" and "propagation" tests
  tools/memory-model: Add model support for spin_is_locked()
  tools/memory-model: Add scripts to test memory model
  tools/memory-model: Fix coding style in 'linux-kernel.def'
  tools/memory-model: Model 'smp_store_mb()'
  tools/memory-order: Update the cheat-sheet to show that smp_mb__after_atomic() orders later RMW operations
  tools/memory-order: Improve key for SELF and SV
  tools/memory-model: Fix cheat sheet typo
  tools/memory-model: Update required version of herdtools7
  tools/memory-model: Redefine rb in terms of rcu-fence
  tools/memory-model: Rename link and rcu-path to rcu-link and rb
  ...
2018-06-04 16:40:11 -07:00
Linus Torvalds
e5a594643a dma-mapping updates for 4.18:
- replaceme the force_dma flag with a dma_configure bus method.
    (Nipun Gupta, although one patch is іncorrectly attributed to me
     due to a git rebase bug)
  - use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai)
  - remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the
    right thing for bounce buffering.
  - move dma-debug initialization to common code, and apply a few cleanups
    to the dma-debug code.
  - cleanup the Kconfig mess around swiotlb selection
  - swiotlb comment fixup (Yisheng Xie)
  - a trivial swiotlb fix. (Dan Carpenter)
  - support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt)
  - add a new generic dma-noncoherent dma_map_ops implementation and use
    it for arc, c6x and nds32.
  - improve scatterlist validity checking in dma-debug. (Robin Murphy)
  - add a struct device quirk to limit the dma-mask to 32-bit due to
    bridge/system issues, and switch x86 to use it instead of a local
    hack for VIA bridges.
  - handle devices without a dma_mask more gracefully in the dma-direct
    code.
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Merge tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - replace the force_dma flag with a dma_configure bus method. (Nipun
   Gupta, although one patch is іncorrectly attributed to me due to a
   git rebase bug)

 - use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai)

 - remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the
   right thing for bounce buffering.

 - move dma-debug initialization to common code, and apply a few
   cleanups to the dma-debug code.

 - cleanup the Kconfig mess around swiotlb selection

 - swiotlb comment fixup (Yisheng Xie)

 - a trivial swiotlb fix. (Dan Carpenter)

 - support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt)

 - add a new generic dma-noncoherent dma_map_ops implementation and use
   it for arc, c6x and nds32.

 - improve scatterlist validity checking in dma-debug. (Robin Murphy)

 - add a struct device quirk to limit the dma-mask to 32-bit due to
   bridge/system issues, and switch x86 to use it instead of a local
   hack for VIA bridges.

 - handle devices without a dma_mask more gracefully in the dma-direct
   code.

* tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping: (48 commits)
  dma-direct: don't crash on device without dma_mask
  nds32: use generic dma_noncoherent_ops
  nds32: implement the unmap_sg DMA operation
  nds32: consolidate DMA cache maintainance routines
  x86/pci-dma: switch the VIA 32-bit DMA quirk to use the struct device flag
  x86/pci-dma: remove the explicit nodac and allowdac option
  x86/pci-dma: remove the experimental forcesac boot option
  Documentation/x86: remove a stray reference to pci-nommu.c
  core, dma-direct: add a flag 32-bit dma limits
  dma-mapping: remove unused gfp_t parameter to arch_dma_alloc_attrs
  dma-debug: check scatterlist segments
  c6x: use generic dma_noncoherent_ops
  arc: use generic dma_noncoherent_ops
  arc: fix arc_dma_{map,unmap}_page
  arc: fix arc_dma_sync_sg_for_{cpu,device}
  arc: simplify arc_dma_sync_single_for_{cpu,device}
  dma-mapping: provide a generic dma-noncoherent implementation
  dma-mapping: simplify Kconfig dependencies
  riscv: add swiotlb support
  riscv: only enable ZONE_DMA32 for 64-bit
  ...
2018-06-04 10:58:12 -07:00
Catalin Marinas
38500be10e arm64: KVM: Move VCPU_WORKAROUND_2_FLAG macros to the top of the file
This is to avoid potential merging conflicts between commit 55e3748e89
("arm64: KVM: Add ARCH_WORKAROUND_2 support for guests") and the KVM
tree.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-06-02 10:42:54 +01:00
Marc Orr
d1e5b0e98e kvm: Make VM ioctl do valloc for some archs
The kvm struct has been bloating. For example, it's tens of kilo-bytes
for x86, which turns out to be a large amount of memory to allocate
contiguously via kzalloc. Thus, this patch does the following:
1. Uses architecture-specific routines to allocate the kvm struct via
   vzalloc for x86.
2. Switches arm to __KVM_HAVE_ARCH_VM_ALLOC so that it can use vzalloc
   when has_vhe() is true.

Other architectures continue to default to kalloc, as they have a
dependency on kalloc or have a small-enough struct kvm.

Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-01 19:18:26 +02:00
Paolo Bonzini
5eec43a1fa KVM/ARM updates for 4.18
- Lazy context-switching of FPSIMD registers on arm64
 - Allow virtual redistributors to be part of two or more MMIO ranges
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Merge tag 'kvmarm-for-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/ARM updates for 4.18

- Lazy context-switching of FPSIMD registers on arm64
- Allow virtual redistributors to be part of two or more MMIO ranges
2018-06-01 19:17:22 +02:00
Dave Martin
94b07c1f8c arm64: signal: Report signal frame size to userspace via auxv
Stateful CPU architecture extensions may require the signal frame
to grow to a size that exceeds the arch's MINSIGSTKSZ #define.
However, changing this #define is an ABI break.

To allow userspace the option of determining the signal frame size
in a more forwards-compatible way, this patch adds a new auxv entry
tagged with AT_MINSIGSTKSZ, which provides the maximum signal frame
size that the process can observe during its lifetime.

If AT_MINSIGSTKSZ is absent from the aux vector, the caller can
assume that the MINSIGSTKSZ #define is sufficient.  This allows for
a consistent interface with older kernels that do not provide
AT_MINSIGSTKSZ.

The idea is that libc could expose this via sysconf() or some
similar mechanism.

There is deliberately no AT_SIGSTKSZ.  The kernel knows nothing
about userspace's own stack overheads and should not pretend to
know.

For arm64:

The primary motivation for this interface is the Scalable Vector
Extension, which can require at least 4KB or so of extra space
in the signal frame for the largest hardware implementations.

To determine the correct value, a "Christmas tree" mode (via the
add_all argument) is added to setup_sigframe_layout(), to simulate
addition of all possible records to the signal frame at maximum
possible size.

If this procedure goes wrong somehow, resulting in a stupidly large
frame layout and hence failure of sigframe_alloc() to allocate a
record to the frame, then this is indicative of a kernel bug.  In
this case, we WARN() and no attempt is made to populate
AT_MINSIGSTKSZ for userspace.

For arm64 SVE:

The SVE context block in the signal frame needs to be considered
too when computing the maximum possible signal frame size.

Because the size of this block depends on the vector length, this
patch computes the size based not on the thread's current vector
length but instead on the maximum possible vector length: this
determines the maximum size of SVE context block that can be
observed in any signal frame for the lifetime of the process.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-06-01 15:53:10 +01:00
Marc Zyngier
5d81f7dc9b arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_ID
Now that all our infrastructure is in place, let's expose the
availability of ARCH_WORKAROUND_2 to guests. We take this opportunity
to tidy up a couple of SMCCC constants.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 18:00:59 +01:00
Marc Zyngier
55e3748e89 arm64: KVM: Add ARCH_WORKAROUND_2 support for guests
In order to offer ARCH_WORKAROUND_2 support to guests, we need
a bit of infrastructure.

Let's add a flag indicating whether or not the guest uses
SSBD mitigation. Depending on the state of this flag, allow
KVM to disable ARCH_WORKAROUND_2 before entering the guest,
and enable it when exiting it.

Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 18:00:55 +01:00
Marc Zyngier
85478bab40 arm64: KVM: Add HYP per-cpu accessors
As we're going to require to access per-cpu variables at EL2,
let's craft the minimum set of accessors required to implement
reading a per-cpu variable, relying on tpidr_el2 to contain the
per-cpu offset.

Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 18:00:53 +01:00
Marc Zyngier
9dd9614f54 arm64: ssbd: Introduce thread flag to control userspace mitigation
In order to allow userspace to be mitigated on demand, let's
introduce a new thread flag that prevents the mitigation from
being turned off when exiting to userspace, and doesn't turn
it on on entry into the kernel (with the assumption that the
mitigation is always enabled in the kernel itself).

This will be used by a prctl interface introduced in a later
patch.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 17:35:32 +01:00
Marc Zyngier
647d0519b5 arm64: ssbd: Restore mitigation status on CPU resume
On a system where firmware can dynamically change the state of the
mitigation, the CPU will always come up with the mitigation enabled,
including when coming back from suspend.

If the user has requested "no mitigation" via a command line option,
let's enforce it by calling into the firmware again to disable it.

Similarily, for a resume from hibernate, the mitigation could have
been disabled by the boot kernel. Let's ensure that it is set
back on in that case.

Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 17:35:19 +01:00
Marc Zyngier
c32e1736ca arm64: ssbd: Add global mitigation state accessor
We're about to need the mitigation state in various parts of the
kernel in order to do the right thing for userspace and guests.

Let's expose an accessor that will let other subsystems know
about the state.

Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 17:34:57 +01:00
Marc Zyngier
a43ae4dfe5 arm64: Add 'ssbd' command-line option
On a system where the firmware implements ARCH_WORKAROUND_2,
it may be useful to either permanently enable or disable the
workaround for cases where the user decides that they'd rather
not get a trap overhead, and keep the mitigation permanently
on or off instead of switching it on exception entry/exit.

In any case, default to the mitigation being enabled.

Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 17:34:49 +01:00
Marc Zyngier
a725e3dda1 arm64: Add ARCH_WORKAROUND_2 probing
As for Spectre variant-2, we rely on SMCCC 1.1 to provide the
discovery mechanism for detecting the SSBD mitigation.

A new capability is also allocated for that purpose, and a
config option.

Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31 17:34:38 +01:00
Eric Auger
6e4076735d KVM: arm/arm64: Add KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
This new attribute allows the userspace to set the base address
of a reditributor region, relaxing the constraint of having all
consecutive redistibutor frames contiguous.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:29:27 +01:00
Dave Martin
21cdd7fd76 KVM: arm64: Remove eager host SVE state saving
Now that the host SVE context can be saved on demand from Hyp,
there is no longer any need to save this state in advance before
entering the guest.

This patch removes the relevant call to
kvm_fpsimd_flush_cpu_state().

Since the problem that function was intended to solve now no longer
exists, the function and its dependencies are also deleted.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:28:30 +01:00
Dave Martin
85acda3b4a KVM: arm64: Save host SVE context as appropriate
This patch adds SVE context saving to the hyp FPSIMD context switch
path.  This means that it is no longer necessary to save the host
SVE state in advance of entering the guest, when in use.

In order to avoid adding pointless complexity to the code, VHE is
assumed if SVE is in use.  VHE is an architectural prerequisite for
SVE, so there is no good reason to turn CONFIG_ARM64_VHE off in
kernels that support both SVE and KVM.

Historically, software models exist that can expose the
architecturally invalid configuration of SVE without VHE, so if
this situation is detected at kvm_init() time then KVM will be
disabled.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:28:29 +01:00
Dave Martin
9a6e594869 arm64/sve: Move sve_pffr() to fpsimd.h and make inline
In order to make sve_save_state()/sve_load_state() more easily
reusable and to get rid of a potential branch on context switch
critical paths, this patch makes sve_pffr() inline and moves it to
fpsimd.h.

<asm/processor.h> must be included in fpsimd.h in order to make
this work, and this creates an #include cycle that is tricky to
avoid without modifying core code, due to the way the PR_SVE_*()
prctl helpers are included in the core prctl implementation.

Instead of breaking the cycle, this patch defers inclusion of
<asm/fpsimd.h> in <asm/processor.h> until the point where it is
actually needed: i.e., immediately before the prctl definitions.

No functional change.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:28:29 +01:00
Dave Martin
31dc52b3c8 arm64/sve: Move read_zcr_features() out of cpufeature.h
Having read_zcr_features() inline in cpufeature.h results in that
header requiring #includes which make it hard to include
<asm/fpsimd.h> elsewhere without triggering header inclusion
cycles.

This is not a hot-path function and arguably should not be in
cpufeature.h in the first place, so this patch moves it to
fpsimd.c, compiled conditionally if CONFIG_ARM64_SVE=y.

This allows some SVE-related #includes to be dropped from
cpufeature.h, which will ease future maintenance.

A couple of missing #includes of <asm/fpsimd.h> are exposed by this
change under arch/arm64/.  This patch adds the missing #includes as
necessary.

No functional change.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:28:29 +01:00
Dave Martin
e6b673b741 KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing
This patch refactors KVM to align the host and guest FPSIMD
save/restore logic with each other for arm64.  This reduces the
number of redundant save/restore operations that must occur, and
reduces the common-case IRQ blackout time during guest exit storms
by saving the host state lazily and optimising away the need to
restore the host state before returning to the run loop.

Four hooks are defined in order to enable this:

 * kvm_arch_vcpu_run_map_fp():
   Called on PID change to map necessary bits of current to Hyp.

 * kvm_arch_vcpu_load_fp():
   Set up FP/SIMD for entering the KVM run loop (parse as
   "vcpu_load fp").

 * kvm_arch_vcpu_ctxsync_fp():
   Get FP/SIMD into a safe state for re-enabling interrupts after a
   guest exit back to the run loop.

   For arm64 specifically, this involves updating the host kernel's
   FPSIMD context tracking metadata so that kernel-mode NEON use
   will cause the vcpu's FPSIMD state to be saved back correctly
   into the vcpu struct.  This must be done before re-enabling
   interrupts because kernel-mode NEON may be used by softirqs.

 * kvm_arch_vcpu_put_fp():
   Save guest FP/SIMD state back to memory and dissociate from the
   CPU ("vcpu_put fp").

Also, the arm64 FPSIMD context switch code is updated to enable it
to save back FPSIMD state for a vcpu, not just current.  A few
helpers drive this:

 * fpsimd_bind_state_to_cpu(struct user_fpsimd_state *fp):
   mark this CPU as having context fp (which may belong to a vcpu)
   currently loaded in its registers.  This is the non-task
   equivalent of the static function fpsimd_bind_to_cpu() in
   fpsimd.c.

 * task_fpsimd_save():
   exported to allow KVM to save the guest's FPSIMD state back to
   memory on exit from the run loop.

 * fpsimd_flush_state():
   invalidate any context's FPSIMD state that is currently loaded.
   Used to disassociate the vcpu from the CPU regs on run loop exit.

These changes allow the run loop to enable interrupts (and thus
softirqs that may use kernel-mode NEON) without having to save the
guest's FPSIMD state eagerly.

Some new vcpu_arch fields are added to make all this work.  Because
host FPSIMD state can now be saved back directly into current's
thread_struct as appropriate, host_cpu_context is no longer used
for preserving the FPSIMD state.  However, it is still needed for
preserving other things such as the host's system registers.  To
avoid ABI churn, the redundant storage space in host_cpu_context is
not removed for now.

arch/arm is not addressed by this patch and continues to use its
current save/restore logic.  It could provide implementations of
the helpers later if desired.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:28:28 +01:00
Dave Martin
fa89d31c53 KVM: arm64: Repurpose vcpu_arch.debug_flags for general-purpose flags
In struct vcpu_arch, the debug_flags field is used to store
debug-related flags about the vcpu state.

Since we are about to add some more flags related to FPSIMD and
SVE, it makes sense to add them to the existing flags field rather
than adding new fields.  Since there is only one debug_flags flag
defined so far, there is plenty of free space for expansion.

In preparation for adding more flags, this patch renames the
debug_flags field to simply "flags", and updates comments
appropriately.

The flag definitions are also moved to <asm/kvm_host.h>, since
their presence in <asm/kvm_asm.h> was for purely historical
reasons:  these definitions are not used from asm any more, and not
very likely to be as more Hyp asm is migrated to C.

KVM_ARM64_DEBUG_DIRTY_SHIFT has not been used since commit
1ea66d27e7 ("arm64: KVM: Move away from the assembly version of
the world switch"), so this patch gets rid of that too.

No functional change.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
[maz: fixed minor conflict]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:28:13 +01:00
Dave Martin
df3fb96820 arm64: fpsimd: Eliminate task->mm checks
Currently the FPSIMD handling code uses the condition task->mm ==
NULL as a hint that task has no FPSIMD register context.

The ->mm check is only there to filter out tasks that cannot
possibly have FPSIMD context loaded, for optimisation purposes.
Also, TIF_FOREIGN_FPSTATE must always be checked anyway before
saving FPSIMD context back to memory.  For these reasons, the ->mm
checks are not useful, providing that TIF_FOREIGN_FPSTATE is
maintained in a consistent way for all threads.

The context switch logic is already deliberately optimised to defer
reloads of the regs until ret_to_user (or sigreturn as a special
case), and save them only if they have been previously loaded.
These paths are the only places where the wrong_task and wrong_cpu
conditions can be made false, by calling fpsimd_bind_task_to_cpu().
Kernel threads by definition never reach these paths.  As a result,
the wrong_task and wrong_cpu tests in fpsimd_thread_switch() will
always yield true for kernel threads.

This patch removes the redundant checks and special-case code,
ensuring that TIF_FOREIGN_FPSTATE is set whenever a kernel thread
is scheduled in, and ensures that this flag is set for the init
task.  The fpsimd_flush_task_state() call already present in
copy_thread() ensures the same for any new task.

With TIF_FOREIGN_FPSTATE always set for kernel threads, this patch
ensures that no extra context save work is added for kernel
threads, and eliminates the redundant context saving that may
currently occur for kernel threads that have acquired an mm via
use_mm().

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:27:55 +01:00
Dave Martin
66e48a0d29 arm64: fpsimd: Avoid FPSIMD context leakage for the init task
The init task is started with thread_flags equal to 0, which means
that TIF_FOREIGN_FPSTATE is initially clear.

It is theoretically possible (if unlikely) that the init task could
reach userspace without ever being scheduled out.  If this occurs,
data left in the FPSIMD registers by the kernel could be exposed.

This patch fixes this anomaly by ensuring that the init task's
initial TIF_FOREIGN_FPSTATE is set.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Fixes: 005f78cd88 ("arm64: defer reloading a task's FPSIMD state to userland resume")
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:27:55 +01:00
Ingo Molnar
675c00c332 Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-25 08:11:28 +02:00
Will Deacon
32c3fa7cdf arm64: lse: Add early clobbers to some input/output asm operands
For LSE atomics that read and write a register operand, we need to
ensure that these operands are annotated as "early clobber" if the
register is written before all of the input operands have been consumed.
Failure to do so can result in the compiler allocating the same register
to both operands, leading to splats such as:

 Unable to handle kernel paging request at virtual address 11111122222221
 [...]
 x1 : 1111111122222222 x0 : 1111111122222221
 Process swapper/0 (pid: 1, stack limit = 0x000000008209f908)
 Call trace:
  test_atomic64+0x1360/0x155c

where x0 has been allocated as both the value to be stored and also the
atomic_t pointer.

This patch adds the missing clobbers.

Cc: <stable@vger.kernel.org>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Reported-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-05-21 19:00:36 +01:00
Mark Rutland
46c4a30b0b arm64: KVM: Use lm_alias() for kvm_ksym_ref()
For historical reasons, we open-code lm_alias() in kvm_ksym_ref().

Let's use lm_alias() to avoid duplication and make things clearer.

As we have to pull this from <linux/mm.h> (which is not safe for
inclusion in assembly), we may as well move the kvm_ksym_ref()
definition into the existing !__ASSEMBLY__ block.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-20 11:44:01 +01:00
Thomas Gleixner
b563ea676a Merge branch 'linus' into timers/2038
Merge upstream to pick up changes on which pending patches depend on.
2018-05-19 13:55:40 +02:00
Linus Torvalds
58ddfe6c3a * ARM/ARM64 locking fixes
* x86 fixes: PCID, UMIP, locking
 * Improved support for recent Windows version that have a 2048 Hz
 APIC timer.
 * Rename KVM_HINTS_DEDICATED CPUID bit to KVM_HINTS_REALTIME
 * Better behaved selftests.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:

 - ARM/ARM64 locking fixes

 - x86 fixes: PCID, UMIP, locking

 - improved support for recent Windows version that have a 2048 Hz APIC
   timer

 - rename KVM_HINTS_DEDICATED CPUID bit to KVM_HINTS_REALTIME

 - better behaved selftests

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: rename KVM_HINTS_DEDICATED to KVM_HINTS_REALTIME
  KVM: arm/arm64: VGIC/ITS save/restore: protect kvm_read_guest() calls
  KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock
  KVM: arm/arm64: VGIC/ITS: Promote irq_lock() in update_affinity
  KVM: arm/arm64: Properly protect VGIC locks from IRQs
  KVM: X86: Lower the default timer frequency limit to 200us
  KVM: vmx: update sec exec controls for UMIP iff emulating UMIP
  kvm: x86: Suppress CR3_PCID_INVD bit only when PCIDs are enabled
  KVM: selftests: exit with 0 status code when tests cannot be run
  KVM: hyperv: idr_find needs RCU protection
  x86: Delay skip of emulated hypercall instruction
  KVM: Extend MAX_IRQ_ROUTES to 4096 for all archs
2018-05-17 10:23:36 -07:00
Dave Martin
159fd7b8d3 arm64/sve: Write ZCR_EL1 on context switch only if changed
Writes to ZCR_EL1 are self-synchronising, and so may be expensive
in typical implementations.

This patch adopts the approach used for costly system register
writes elsewhere in the kernel: the system register write is
suppressed if it would not change the stored value.

Since the common case will be that of switching between tasks that
use the same vector length as one another, prediction hit rates on
the conditional branch should be reasonably good, with lower
expected amortised cost than the unconditional execution of a
heavyweight self-synchronising instruction.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-17 18:19:53 +01:00
Jeremy Linton
37c3ec2d81 arm64: topology: divorce MC scheduling domain from core_siblings
Now that we have an accurate view of the physical topology
we need to represent it correctly to the scheduler. Generally MC
should equal the LLC in the system, but there are a number of
special cases that need to be dealt with.

In the case of NUMA in socket, we need to assure that the sched
domain we build for the MC layer isn't larger than the DIE above it.
Similarly for LLC's that might exist in cross socket interconnect or
directory hardware we need to assure that MC is shrunk to the socket
or NUMA node.

This patch builds a sibling mask for the LLC, and then picks the
smallest of LLC, socket siblings, or NUMA node siblings, which
gives us the behavior described above. This is ever so slightly
different than the similar alternative where we look for a cache
layer less than or equal to the socket/NUMA siblings.

The logic to pick the MC layer affects all arm64 machines, but
only changes the behavior for DT/MPIDR systems if the NUMA domain
is smaller than the core siblings (generally set to the cluster).
Potentially this fixes a possible bug in DT systems, but really
it only affects ACPI systems where the core siblings is correctly
set to the socket siblings. Thus all currently available ACPI
systems should have MC equal to LLC, including the NUMA in socket
machines where the LLC is partitioned between the NUMA nodes.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-17 17:28:09 +01:00
Jeremy Linton
868abc0768 arm64: topology: rename cluster_id
The cluster concept isn't architecturally defined for arm64.
Lets match the name of the arm64 topology field to the kernel macro
that uses it.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-17 17:28:09 +01:00
Jeremy Linton
30d87bfacb arm64/acpi: Create arch specific cpu to acpi id helper
Its helpful to be able to lookup the acpi_processor_id associated
with a logical cpu. Provide an arm64 helper to do this.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-17 17:28:09 +01:00
Will Deacon
1cfc63b5ae arm64: cmpwait: Clear event register before arming exclusive monitor
When waiting for a cacheline to change state in cmpwait, we may immediately
wake-up the first time around the outer loop if the event register was
already set (for example, because of the event stream).

Avoid these spurious wakeups by explicitly clearing the event register
before loading the cacheline and setting the exclusive monitor.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-16 12:21:19 +01:00
Vincenzo Frascino
92faa7bea3 arm64: Remove duplicate include
"make includecheck" detected few duplicated includes in arch/arm64.

This patch removes the double inclusions.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-15 18:18:00 +01:00
Catalin Marinas
ebc7e21e0f arm64: Increase ARCH_DMA_MINALIGN to 128
This patch increases the ARCH_DMA_MINALIGN to 128 so that it covers the
currently known Cache Writeback Granule (CTR_EL0.CWG) on arm64 and moves
the fallback in cache_line_size() from L1_CACHE_BYTES to this constant.
In addition, it warns (and taints) if the CWG is larger than
ARCH_DMA_MINALIGN as this is not safe with non-coherent DMA.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-15 13:29:55 +01:00
Andre Przywara
bf308242ab KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock
kvm_read_guest() will eventually look up in kvm_memslots(), which requires
either to hold the kvm->slots_lock or to be inside a kvm->srcu critical
section.
In contrast to x86 and s390 we don't take the SRCU lock on every guest
exit, so we have to do it individually for each kvm_read_guest() call.

Provide a wrapper which does that and use that everywhere.

Note that ending the SRCU critical section before returning from the
kvm_read_guest() wrapper is safe, because the data has been *copied*, so
we don't need to rely on valid references to the memslot anymore.

Cc: Stable <stable@vger.kernel.org> # 4.8+
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-05-15 13:36:49 +02:00
Andrea Parri
c6f5d02b6a locking/spinlocks/arm64: Remove smp_mb() from arch_spin_is_locked()
The following commit:

  38b850a730 ("arm64: spinlock: order spin_{is_locked,unlock_wait} against local locks")

... added an smp_mb() to arch_spin_is_locked(), in order
"to ensure that the lock value is always loaded after any other locks have
been taken by the current CPU", and reported one example (the "insane case"
in ipc/sem.c) relying on such guarantee.

It is however understood that spin_is_locked() is not required to provide
such an ordering guarantee (a guarantee that is currently not provided by
all the implementations/archs), and that callers relying on such ordering
should instead insert suitable memory barriers before acting on the result
of spin_is_locked().

Following a recent auditing [1] of the callers of {,raw_}spin_is_locked(),
revealing that none of them are relying on the ordering guarantee anymore,
this commit removes the leading smp_mb() from the primitive thus reverting
38b850a730.

[1] https://marc.info/?l=linux-kernel&m=151981440005264&w=2
    https://marc.info/?l=linux-kernel&m=152042843808540&w=2
    https://marc.info/?l=linux-kernel&m=152043346110262&w=2

Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: stern@rowland.harvard.edu
Link: http://lkml.kernel.org/r/1526338889-7003-2-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15 08:11:15 +02:00
Linus Torvalds
7404bc2773 arm64 fixes:
- Mitigate Spectre-v2 for NVIDIA Denver CPUs
 
 - Free memblocks corresponding to freed initrd area
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "There's a small memblock accounting problem when freeing the initrd
  and a Spectre-v2 mitigation for NVIDIA Denver CPUs which just requires
  a match on the CPU ID register.

  Summary:

   - Mitigate Spectre-v2 for NVIDIA Denver CPUs

   - Free memblocks corresponding to freed initrd area"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: capabilities: Add NVIDIA Denver CPU to bp_harden list
  arm64: Add MIDR encoding for NVIDIA CPUs
  arm64: To remove initrd reserved area entry from memblock
2018-05-11 13:09:04 -07:00
Catalin Marinas
d93277b983 Revert "arm64: Increase the max granular size"
This reverts commit 9730348075.

Commit 9730348075 ("arm64: Increase the max granular size") increased
the cache line size to 128 to match Cavium ThunderX, apparently for some
performance benefit which could not be confirmed. This change, however,
has an impact on the network packet allocation in certain circumstances,
requiring slightly over a 4K page with a significant performance
degradation. The patch reverts L1_CACHE_SHIFT back to 6 (64-byte cache
line).

Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-11 14:21:33 +01:00
David Gilhooley
1b06bd8dd9 arm64: Add MIDR encoding for NVIDIA CPUs
This patch adds the MIDR encodings for NVIDIA as well as
the Denver and Carmel CPUs used in Tegra SoCs.

Signed-off-by: David Gilhooley <dgilhooley@nvidia.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-05-09 14:28:20 +01:00
Christoph Hellwig
325ef1857f PCI: remove PCI_DMA_BUS_IS_PHYS
This was used by the ide, scsi and networking code in the past to
determine if they should bounce payloads.  Now that the dma mapping
always have to support dma to all physical memory (thanks to swiotlb
for non-iommu systems) there is no need to this crude hack any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Palmer Dabbelt <palmer@sifive.com> (for riscv)
Reviewed-by: Jens Axboe <axboe@kernel.dk>
2018-05-07 07:15:41 +02:00
Radim Krčmář
f3351c609b KVM/arm fixes for 4.17, take #2
- Fix proxying of GICv2 CPU interface accesses
 - Fix crash when switching to BE
 - Track source vcpu git GICv2 SGIs
 - Fix an outdated bit of documentation
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Merge tag 'kvmarm-fixes-for-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm

KVM/arm fixes for 4.17, take #2

- Fix proxying of GICv2 CPU interface accesses
- Fix crash when switching to BE
- Track source vcpu git GICv2 SGIs
- Fix an outdated bit of documentation
2018-05-05 23:05:31 +02:00
James Morse
1975fa56f1 KVM: arm64: Fix order of vcpu_write_sys_reg() arguments
A typo in kvm_vcpu_set_be()'s call:
| vcpu_write_sys_reg(vcpu, SCTLR_EL1, sctlr)
causes us to use the 32bit register value as an index into the sys_reg[]
array, and sail off the end of the linear map when we try to bring up
big-endian secondaries.

| Unable to handle kernel paging request at virtual address ffff80098b982c00
| Mem abort info:
|  ESR = 0x96000045
|  Exception class = DABT (current EL), IL = 32 bits
|   SET = 0, FnV = 0
|   EA = 0, S1PTW = 0
| Data abort info:
|   ISV = 0, ISS = 0x00000045
|   CM = 0, WnR = 1
| swapper pgtable: 4k pages, 48-bit VAs, pgdp = 000000002ea0571a
| [ffff80098b982c00] pgd=00000009ffff8803, pud=0000000000000000
| Internal error: Oops: 96000045 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 2 PID: 1561 Comm: kvm-vcpu-0 Not tainted 4.17.0-rc3-00001-ga912e2261ca6-dirty #1323
| Hardware name: ARM Juno development board (r1) (DT)
| pstate: 60000005 (nZCv daif -PAN -UAO)
| pc : vcpu_write_sys_reg+0x50/0x134
| lr : vcpu_write_sys_reg+0x50/0x134

| Process kvm-vcpu-0 (pid: 1561, stack limit = 0x000000006df4728b)
| Call trace:
|  vcpu_write_sys_reg+0x50/0x134
|  kvm_psci_vcpu_on+0x14c/0x150
|  kvm_psci_0_2_call+0x244/0x2a4
|  kvm_hvc_call_handler+0x1cc/0x258
|  handle_hvc+0x20/0x3c
|  handle_exit+0x130/0x1ec
|  kvm_arch_vcpu_ioctl_run+0x340/0x614
|  kvm_vcpu_ioctl+0x4d0/0x840
|  do_vfs_ioctl+0xc8/0x8d0
|  ksys_ioctl+0x78/0xa8
|  sys_ioctl+0xc/0x18
|  el0_svc_naked+0x30/0x34
| Code: 73620291 604d00b0 00201891 1ab10194 (957a33f8)
|---[ end trace 4b4a4f9628596602 ]---

Fix the order of the arguments.

Fixes: 8d404c4c24 ("KVM: arm64: Rewrite system register accessors to read/write functions")
CC: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-04 16:44:54 +01:00
Thomas Gleixner
604a98f1df Merge branch 'timers/urgent' into timers/core
Pick up urgent fixes to apply dependent cleanup patch
2018-05-02 16:11:12 +02:00
Linus Torvalds
46dc111dfe KVM fixes for v4.17-rc3
ARM:
  - PSCI selection API, a leftover from 4.16 (for stable)
  - Kick vcpu on active interrupt affinity change
  - Plug a VMID allocation race on oversubscribed systems
  - Silence debug messages
  - Update Christoffer's email address (linaro -> arm)
 
 x86:
  - Expose userspace-relevant bits of a newly added feature
  - Fix TLB flushing on VMX with VPID, but without EPT
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rMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - PSCI selection API, a leftover from 4.16 (for stable)
   - Kick vcpu on active interrupt affinity change
   - Plug a VMID allocation race on oversubscribed systems
   - Silence debug messages
   - Update Christoffer's email address (linaro -> arm)

  x86:
   - Expose userspace-relevant bits of a newly added feature
   - Fix TLB flushing on VMX with VPID, but without EPT"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  x86/headers/UAPI: Move DISABLE_EXITS KVM capability bits to the UAPI
  kvm: apic: Flush TLB after APIC mode/address change if VPIDs are in use
  arm/arm64: KVM: Add PSCI version selection API
  KVM: arm/arm64: vgic: Kick new VCPU on interrupt migration
  arm64: KVM: Demote SVE and LORegion warnings to debug only
  MAINTAINERS: Update e-mail address for Christoffer Dall
  KVM: arm/arm64: Close VMID generation race
2018-04-27 16:13:31 -07:00
Kim Phillips
ed231ae384 arm64/kernel: rename module_emit_adrp_veneer->module_emit_veneer_for_adrp
Commit a257e02579 ("arm64/kernel: don't ban ADRP to work around
Cortex-A53 erratum #843419") introduced a function whose name ends with
"_veneer".

This clashes with commit bd8b22d288 ("Kbuild: kallsyms: ignore veneers
emitted by the ARM linker"), which removes symbols ending in "_veneer"
from kallsyms.

The problem was manifested as 'perf test -vvvvv vmlinux' failed,
correctly claiming the symbol 'module_emit_adrp_veneer' was present in
vmlinux, but not in kallsyms.

...
    ERR : 0xffff00000809aa58: module_emit_adrp_veneer not on kallsyms
...
    test child finished with -1
    ---- end ----
    vmlinux symtab matches kallsyms: FAILED!

Fix the problem by renaming module_emit_adrp_veneer to
module_emit_veneer_for_adrp.  Now the test passes.

Fixes: a257e02579 ("arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419")
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-24 19:07:35 +01:00
Shaokun Zhang
907e21c15c arm64: mm: drop addr parameter from sync icache and dcache
The addr parameter isn't used for anything. Let's simplify and get rid of
it, like arm.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-24 09:23:00 +01:00
Marc Zyngier
85bd0ba1ff arm/arm64: KVM: Add PSCI version selection API
Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1
or 1.0 to a guest, defaulting to the latest version of the PSCI
implementation that is compatible with the requested version. This is
no different from doing a firmware upgrade on KVM.

But in order to give a chance to hypothetical badly implemented guests
that would have a fit by discovering something other than PSCI 0.2,
let's provide a new API that allows userspace to pick one particular
version of the API.

This is implemented as a new class of "firmware" registers, where
we expose the PSCI version. This allows the PSCI version to be
save/restored as part of a guest migration, and also set to
any supported version if the guest requires it.

Cc: stable@vger.kernel.org #4.16
Reviewed-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-04-20 16:32:23 +01:00
Arnd Bergmann
83335eb4f6 y2038: arm64: Extend sysvipc compat data structures
Both 32-bit amd 64-bit ARM use the asm-generic header files for their
sysvipc data structures, so no special care is needed to make those
work beyond y2038, with the one exception of compat mode: Since there
is no asm-generic definition of the compat mode IPC structures, ARM64
provides its own copy, and we make those match the changes in the native
asm-generic header files.

There is sufficient padding in these data structures to extend all
timestamps to 64 bit, but on big-endian ARM kernels, the padding
is in the wrong place, so the C library has to ensure it reassembles
a 64-bit time_t correctly.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-04-20 16:20:01 +02:00
Deepa Dinamani
0d55303c51 compat: Move compat_timespec/ timeval to compat_time.h
All the current architecture specific defines for these
are the same. Refactor these common defines to a common
header file.

The new common linux/compat_time.h is also useful as it
will eventually be used to hold all the defines that
are needed for compat time types that support non y2038
safe types. New architectures need not have to define these
new types as they will only use new y2038 safe syscalls.
This file can be deleted after y2038 when we stop supporting
non y2038 safe syscalls.

The patch also requires an operation similar to:

git grep "asm/compat\.h" | cut -d ":" -f 1 |  xargs -n 1 sed -i -e "s%asm/compat.h%linux/compat.h%g"

Cc: acme@kernel.org
Cc: benh@kernel.crashing.org
Cc: borntraeger@de.ibm.com
Cc: catalin.marinas@arm.com
Cc: cmetcalf@mellanox.com
Cc: cohuck@redhat.com
Cc: davem@davemloft.net
Cc: deller@gmx.de
Cc: devel@driverdev.osuosl.org
Cc: gerald.schaefer@de.ibm.com
Cc: gregkh@linuxfoundation.org
Cc: heiko.carstens@de.ibm.com
Cc: hoeppner@linux.vnet.ibm.com
Cc: hpa@zytor.com
Cc: jejb@parisc-linux.org
Cc: jwi@linux.vnet.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: mark.rutland@arm.com
Cc: mingo@redhat.com
Cc: mpe@ellerman.id.au
Cc: oberpar@linux.vnet.ibm.com
Cc: oprofile-list@lists.sf.net
Cc: paulus@samba.org
Cc: peterz@infradead.org
Cc: ralf@linux-mips.org
Cc: rostedt@goodmis.org
Cc: rric@kernel.org
Cc: schwidefsky@de.ibm.com
Cc: sebott@linux.vnet.ibm.com
Cc: sparclinux@vger.kernel.org
Cc: sth@linux.vnet.ibm.com
Cc: ubraun@linux.vnet.ibm.com
Cc: will.deacon@arm.com
Cc: x86@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: James Hogan <jhogan@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-04-19 13:29:54 +02:00
Linus Torvalds
e4e57f20fa Additional arm64 updates for 4.17
A few late updates to address some issues arising from conflicts with
 other trees:
 
 - Removal of Qualcomm-specific Spectre-v2 mitigation in favour of the
   generic SMCCC-based firmware call
 
 - Fix EL2 hardening capability checking, which was bodged to reduce
   conflicts with the KVM tree
 
 - Add some currently unused assembler macros for managing SIMD registers
   which will be used by some crypto code in the next merge window
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull more arm64 updates from Will Deacon:
 "A few late updates to address some issues arising from conflicts with
  other trees:

   - Removal of Qualcomm-specific Spectre-v2 mitigation in favour of the
     generic SMCCC-based firmware call

   - Fix EL2 hardening capability checking, which was bodged to reduce
     conflicts with the KVM tree

   - Add some currently unused assembler macros for managing SIMD
     registers which will be used by some crypto code in the next merge
     window"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: assembler: add macros to conditionally yield the NEON under PREEMPT
  arm64: assembler: add utility macros to push/pop stack frames
  arm64: Move the content of bpi.S to hyp-entry.S
  arm64: Get rid of __smccc_workaround_1_hvc_*
  arm64: capabilities: Rework EL2 vector hardening entry
  arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening
2018-04-13 11:24:18 -07:00
Ard Biesheuvel
24534b3511 arm64: assembler: add macros to conditionally yield the NEON under PREEMPT
Add support macros to conditionally yield the NEON (and thus the CPU)
that may be called from the assembler code.

In some cases, yielding the NEON involves saving and restoring a non
trivial amount of context (especially in the CRC folding algorithms),
and so the macro is split into three, and the code in between is only
executed when the yield path is taken, allowing the context to be preserved.
The third macro takes an optional label argument that marks the resume
path after a yield has been performed.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:50:34 +01:00
Ard Biesheuvel
0f468e221c arm64: assembler: add utility macros to push/pop stack frames
We are going to add code to all the NEON crypto routines that will
turn them into non-leaf functions, so we need to manage the stack
frames. To make this less tedious and error prone, add some macros
that take the number of callee saved registers to preserve and the
extra size to allocate in the stack frame (for locals) and emit
the ldp/stp sequences.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:50:34 +01:00
Shanker Donthineni
4bc352ffb3 arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening
The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC
V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses
the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead
of Silicon provider service ID 0xC2001700.

Cc: <stable@vger.kernel.org> # 4.14+
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
[maz: reworked errata framework integration]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-11 18:49:30 +01:00
Matthew Wilcox
427c896f26 arm64: turn flush_dcache_mmap_lock into a no-op
ARM64 doesn't walk the VMA tree in its flush_dcache_page()
implementation, so has no need to take the tree_lock.

Link: http://lkml.kernel.org/r/20180313132639.17387-4-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:39 -07:00
Masahiro Yamada
2dd8a62c64 linux/const.h: move UL() macro to include/linux/const.h
ARM, ARM64 and UniCore32 duplicate the definition of UL():

  #define UL(x) _AC(x, UL)

This is not actually arch-specific, so it will be useful to move it to a
common header.  Currently, we only have the uapi variant for
linux/const.h, so I am creating include/linux/const.h.

I also added _UL(), _ULL() and ULL() because _AC() is mostly used in
the form either _AC(..., UL) or _AC(..., ULL).  I expect they will be
replaced in follow-up cleanups.  The underscore-prefixed ones should
be used for exported headers.

Link: http://lkml.kernel.org/r/1519301715-31798-4-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:38 -07:00
Linus Torvalds
d8312a3f61 ARM:
- VHE optimizations
 - EL2 address space randomization
 - speculative execution mitigations ("variant 3a", aka execution past invalid
 privilege register access)
 - bugfixes and cleanups
 
 PPC:
 - improvements for the radix page fault handler for HV KVM on POWER9
 
 s390:
 - more kvm stat counters
 - virtio gpu plumbing
 - documentation
 - facilities improvements
 
 x86:
 - support for VMware magic I/O port and pseudo-PMCs
 - AMD pause loop exiting
 - support for AMD core performance extensions
 - support for synchronous register access
 - expose nVMX capabilities to userspace
 - support for Hyper-V signaling via eventfd
 - use Enlightened VMCS when running on Hyper-V
 - allow userspace to disable MWAIT/HLT/PAUSE vmexits
 - usual roundup of optimizations and nested virtualization bugfixes
 
 Generic:
 - API selftest infrastructure (though the only tests are for x86 as of now)
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - VHE optimizations

   - EL2 address space randomization

   - speculative execution mitigations ("variant 3a", aka execution past
     invalid privilege register access)

   - bugfixes and cleanups

  PPC:
   - improvements for the radix page fault handler for HV KVM on POWER9

  s390:
   - more kvm stat counters

   - virtio gpu plumbing

   - documentation

   - facilities improvements

  x86:
   - support for VMware magic I/O port and pseudo-PMCs

   - AMD pause loop exiting

   - support for AMD core performance extensions

   - support for synchronous register access

   - expose nVMX capabilities to userspace

   - support for Hyper-V signaling via eventfd

   - use Enlightened VMCS when running on Hyper-V

   - allow userspace to disable MWAIT/HLT/PAUSE vmexits

   - usual roundup of optimizations and nested virtualization bugfixes

  Generic:
   - API selftest infrastructure (though the only tests are for x86 as
     of now)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (174 commits)
  kvm: x86: fix a prototype warning
  kvm: selftests: add sync_regs_test
  kvm: selftests: add API testing infrastructure
  kvm: x86: fix a compile warning
  KVM: X86: Add Force Emulation Prefix for "emulate the next instruction"
  KVM: X86: Introduce handle_ud()
  KVM: vmx: unify adjacent #ifdefs
  x86: kvm: hide the unused 'cpu' variable
  KVM: VMX: remove bogus WARN_ON in handle_ept_misconfig
  Revert "KVM: X86: Fix SMRAM accessing even if VM is shutdown"
  kvm: Add emulation for movups/movupd
  KVM: VMX: raise internal error for exception during invalid protected mode state
  KVM: nVMX: Optimization: Dont set KVM_REQ_EVENT when VMExit with nested_run_pending
  KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event pending
  KVM: x86: Fix misleading comments on handling pending exceptions
  KVM: x86: Rename interrupt.pending to interrupt.injected
  KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interrupt
  x86/kvm: use Enlightened VMCS when running on Hyper-V
  x86/hyper-v: detect nested features
  x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits
  ...
2018-04-09 11:42:31 -07:00
Linus Torvalds
23221d997b arm64 updates for 4.17
Nothing particularly stands out here, probably because people were tied
 up with spectre/meltdown stuff last time around. Still, the main pieces
 are:
 
 - Rework of our CPU features framework so that we can whitelist CPUs that
   don't require kpti even in a heterogeneous system
 
 - Support for the IDC/DIC architecture extensions, which allow us to elide
   instruction and data cache maintenance when writing out instructions
 
 - Removal of the large memory model which resulted in suboptimal codegen
   by the compiler and increased the use of literal pools, which could
   potentially be used as ROP gadgets since they are mapped as executable
 
 - Rework of forced signal delivery so that the siginfo_t is well-formed
   and handling of show_unhandled_signals is consolidated and made
   consistent between different fault types
 
 - More siginfo cleanup based on the initial patches from Eric Biederman
 
 - Workaround for Cortex-A55 erratum #1024718
 
 - Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi
 
 - Misc cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Nothing particularly stands out here, probably because people were
  tied up with spectre/meltdown stuff last time around. Still, the main
  pieces are:

   - Rework of our CPU features framework so that we can whitelist CPUs
     that don't require kpti even in a heterogeneous system

   - Support for the IDC/DIC architecture extensions, which allow us to
     elide instruction and data cache maintenance when writing out
     instructions

   - Removal of the large memory model which resulted in suboptimal
     codegen by the compiler and increased the use of literal pools,
     which could potentially be used as ROP gadgets since they are
     mapped as executable

   - Rework of forced signal delivery so that the siginfo_t is
     well-formed and handling of show_unhandled_signals is consolidated
     and made consistent between different fault types

   - More siginfo cleanup based on the initial patches from Eric
     Biederman

   - Workaround for Cortex-A55 erratum #1024718

   - Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi

   - Misc cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits)
  arm64: uaccess: Fix omissions from usercopy whitelist
  arm64: fpsimd: Split cpu field out from struct fpsimd_state
  arm64: tlbflush: avoid writing RES0 bits
  arm64: cmpxchg: Include linux/compiler.h in asm/cmpxchg.h
  arm64: move percpu cmpxchg implementation from cmpxchg.h to percpu.h
  arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG
  arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC
  arm64: fpsimd: include <linux/init.h> in fpsimd.h
  drivers/perf: arm_pmu_platform: do not warn about affinity on uniprocessor
  perf: arm_spe: include linux/vmalloc.h for vmap()
  Revert "arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)"
  arm64: cpufeature: Avoid warnings due to unused symbols
  arm64: Add work around for Arm Cortex-A55 Erratum 1024718
  arm64: Delay enabling hardware DBM feature
  arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35
  arm64: capabilities: Handle shared entries
  arm64: capabilities: Add support for checks based on a list of MIDRs
  arm64: Add helpers for checking CPU MIDR against a range
  arm64: capabilities: Clean up midr range helpers
  arm64: capabilities: Change scope of VHE to Boot CPU feature
  ...
2018-04-04 16:01:43 -07:00
Linus Torvalds
5b1f3dc927 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "The usual pile of boring changes:

   - Consolidate tasklet functions to share code instead of duplicating
     it

   - The first step for making the low level entry handler management on
     multi-platform kernels generic

   - A new sysfs file which allows to retrieve the wakeup state of
     interrupts.

   - Ensure that the interrupt thread follows the effective affinity and
     not the programmed affinity to avoid cross core wakeups.

   - Two new interrupt controller drivers (Microsemi Ocelot and Qualcomm
     PDC)

   - Fix the wakeup path clock handling for Reneasas interrupt chips.

   - Rework the boot time register reset for ARM GIC-V2/3

   - Better suspend/resume support for ARM GIV-V3/ITS

   - Add missing locking to the ARM GIC set_type() callback

   - Small fixes for the irq simulator code

   - SPDX identifiers for the irq core code and removal of boiler plate

   - Small cleanups all over the place"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  openrisc: Set CONFIG_MULTI_IRQ_HANDLER
  arm64: Set CONFIG_MULTI_IRQ_HANDLER
  genirq: Make GENERIC_IRQ_MULTI_HANDLER depend on !MULTI_IRQ_HANDLER
  irqchip/gic: Take lock when updating irq type
  irqchip/gic: Update supports_deactivate static key to modern api
  irqchip/gic-v3: Ensure GICR_CTLR.EnableLPI=0 is observed before enabling
  irqchip: Add a driver for the Microsemi Ocelot controller
  dt-bindings: interrupt-controller: Add binding for the Microsemi Ocelot interrupt controller
  irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn
  irqchip/gic-v3: Don't try to reset AP0Rn
  irqchip/gic-v3: Do not check trigger configuration of partitionned LPIs
  genirq: Remove license boilerplate/references
  genirq: Add missing SPDX identifiers
  genirq/matrix: Cleanup SPDX identifier
  genirq: Cleanup top of file comments
  genirq: Pass desc to __irq_free instead of irq number
  irqchip/gic-v3: Loudly complain about the use of IRQ_TYPE_NONE
  irqchip/gic: Loudly complain about the use of IRQ_TYPE_NONE
  RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler
  genirq: Add CONFIG_GENERIC_IRQ_MULTI_HANDLER
  ...
2018-04-04 15:19:26 -07:00
Dave Martin
65896545b6 arm64: uaccess: Fix omissions from usercopy whitelist
When the hardend usercopy support was added for arm64, it was
concluded that all cases of usercopy into and out of thread_struct
were statically sized and so didn't require explicit whitelisting
of the appropriate fields in thread_struct.

Testing with usercopy hardening enabled has revealed that this is
not the case for certain ptrace regset manipulation calls on arm64.
This occurs because the sizes of usercopies associated with the
regset API are dynamic by construction, and because arm64 does not
always stage such copies via the stack: indeed the regset API is
designed to avoid the need for that by adding some bounds checking.

This is currently believed to affect only the fpsimd and TLS
registers.

Because the whitelisted fields in thread_struct must be contiguous,
this patch groups them together in a nested struct.  It is also
necessary to be able to determine the location and size of that
struct, so rather than making the struct anonymous (which would
save on edits elsewhere) or adding an anonymous union containing
named and unnamed instances of the same struct (gross), this patch
gives the struct a name and makes the necessary edits to code that
references it (noisy but simple).

Care is needed to ensure that the new struct does not contain
padding (which the usercopy hardening would fail to protect).

For this reason, the presence of tp2_value is made unconditional,
since a padding field would be needed there in any case.  This pads
up to the 16-byte alignment required by struct user_fpsimd_state.

Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 9e8084d3f7 ("arm64: Implement thread_struct whitelist for hardened usercopy")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-28 15:25:44 +01:00
Dave Martin
20b8547277 arm64: fpsimd: Split cpu field out from struct fpsimd_state
In preparation for using a common representation of the FPSIMD
state for tasks and KVM vcpus, this patch separates out the "cpu"
field that is used to track the cpu on which the state was most
recently loaded.

This will allow common code to operate on task and vcpu contexts
without requiring the cpu field to be stored at the same offset
from the FPSIMD register data in both cases.  This should avoid the
need for messing with the definition of those parts of struct
vcpu_arch that are exposed in the KVM user ABI.

The resulting change is also convenient for grouping and defining
the set of thread_struct fields that are supposed to be accessible
to copy_{to,from}_user(), which includes user_fpsimd_state but
should exclude the cpu field.  This patch does not amend the
usercopy whitelist to match: that will be addressed in a subsequent
patch.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
[will: inline fpsimd_flush_state for now]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-28 15:20:17 +01:00
Philip Elcan
7f170499f7 arm64: tlbflush: avoid writing RES0 bits
Several of the bits of the TLBI register operand are RES0 per the ARM
ARM, so TLBI operations should avoid writing non-zero values to these
bits.

This patch adds a macro __TLBI_VADDR(addr, asid) that creates the
operand register in the correct format and honors the RES0 bits.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Philip Elcan <pelcan@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-28 15:20:17 +01:00
Marc Zyngier
adc91ab785 Revert "arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening"
Creates far too many conflicts with arm64/for-next/core, to be
resent post -rc1.

This reverts commit f9f5dc1950.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-28 12:00:45 +01:00
Will Deacon
2a58fca9a7 arm64: cmpxchg: Include linux/compiler.h in asm/cmpxchg.h
We need linux/compiler.h for unreachable(), so #include it here.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:15:49 +01:00
Will Deacon
c9406e514b arm64: move percpu cmpxchg implementation from cmpxchg.h to percpu.h
We want to avoid pulling linux/preempt.h into cmpxchg.h, since that can
introduce a circular dependency on linux/bitops.h. linux/preempt.h is
only needed by the per-cpu cmpxchg implementation, which is better off
alongside the per-cpu xchg implementation in percpu.h, so move it there
and add the missing #include.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:15:29 +01:00
Will Deacon
e8a2d040fe arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG
Having asm/cmpxchg.h pull in linux/bug.h is problematic because this
ends up pulling in the atomic bitops which themselves may be built on
top of atomic.h and cmpxchg.h.

Instead, just include build_bug.h for the definition of BUILD_BUG.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:14:54 +01:00
Will Deacon
8a624f145c arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC
When the LL/SC atomics are moved out-of-line, they are annotated as
notrace and exported to modules. Ensure we pull in the relevant include
files so that these macros are defined when we need them.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:14:49 +01:00
Will Deacon
b4f9b39074 arm64: fpsimd: include <linux/init.h> in fpsimd.h
fpsimd.h uses the __init annotation, so pull in linux/init.h

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 13:14:43 +01:00
Will Deacon
3f251cf0ab Revert "arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)"
This reverts commit 1f85b42a69.

The internal dma-direct.h API has changed in -next, which collides with
us trying to use it to manage non-coherent DMA devices on systems with
unreasonably large cache writeback granules.

This isn't at all trivial to resolve, so revert our changes for now and
we can revisit this after the merge window. Effectively, this just
restores our behaviour back to that of 4.16.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-27 12:04:51 +01:00
Suzuki K Poulose
05abb595bb arm64: Delay enabling hardware DBM feature
We enable hardware DBM bit in a capable CPU, very early in the
boot via __cpu_setup. This doesn't give us a flexibility of
optionally disable the feature, as the clearing the bit
is a bit costly as the TLB can cache the settings. Instead,
we delay enabling the feature until the CPU is brought up
into the kernel. We use the feature capability mechanism
to handle it.

The hardware DBM is a non-conflicting feature. i.e, the kernel
can safely run with a mix of CPUs with some using the feature
and the others don't. So, it is safe for a late CPU to have
this capability and enable it, even if the active CPUs don't.

To get this handled properly by the infrastructure, we
unconditionally set the capability and only enable it
on CPUs which really have the feature. Also, we print the
feature detection from the "matches" call back to make sure
we don't mislead the user when none of the CPUs could use the
feature.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:44 +01:00
Suzuki K Poulose
6e616864f2 arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35
Update the MIDR encodings for the Cortex-A55 and Cortex-A35

Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:43 +01:00
Suzuki K Poulose
ba7d9233c2 arm64: capabilities: Handle shared entries
Some capabilities have different criteria for detection and associated
actions based on the matching criteria, even though they all share the
same capability bit. So far we have used multiple entries with the same
capability bit to handle this. This is prone to errors, as the
cpu_enable is invoked for each entry, irrespective of whether the
detection rule applies to the CPU or not. And also this complicates
other helpers, e.g, __this_cpu_has_cap.

This patch adds a wrapper entry to cover all the possible variations
of a capability by maintaining list of matches + cpu_enable callbacks.
To avoid complicating the prototypes for the "matches()", we use
arm64_cpu_capabilities maintain the list and we ignore all the other
fields except the matches & cpu_enable.

This ensures :

 1) The capabilitiy is set when at least one of the entry detects
 2) Action is only taken for the entries that "matches".

This avoids explicit checks in the cpu_enable() take some action.
The only constraint here is that, all the entries should have the
same "type" (i.e, scope and conflict rules).

If a cpu_enable() method is associated with multiple matches for a
single capability, care should be taken that either the match criteria
are mutually exclusive, or that the method is robust against being
called multiple times.

This also reverts the changes introduced by commit 67948af41f
("arm64: capabilities: Handle duplicate entries for a capability").

Cc: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:43 +01:00
Suzuki K Poulose
be5b299830 arm64: capabilities: Add support for checks based on a list of MIDRs
Add helpers for detecting an errata on list of midr ranges
of affected CPUs, with the same work around.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:42 +01:00
Suzuki K Poulose
1df310505d arm64: Add helpers for checking CPU MIDR against a range
Add helpers for checking if the given CPU midr falls in a range
of variants/revisions for a given model.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:42 +01:00
Suzuki K Poulose
830dcc9f9a arm64: capabilities: Change scope of VHE to Boot CPU feature
We expect all CPUs to be running at the same EL inside the kernel
with or without VHE enabled and we have strict checks to ensure
that any mismatch triggers a kernel panic. If VHE is enabled,
we use the feature based on the boot CPU and all other CPUs
should follow. This makes it a perfect candidate for a capability
based on the boot CPU,  which should be matched by all the CPUs
(both when is ON and OFF). This saves us some not-so-pretty
hooks and special code, just for verifying the conflict.

The patch also makes the VHE capability entry depend on
CONFIG_ARM64_VHE.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:41 +01:00
Suzuki K Poulose
fd9d63da17 arm64: capabilities: Add support for features enabled early
The kernel detects and uses some of the features based on the boot
CPU and expects that all the following CPUs conform to it. e.g,
with VHE and the boot CPU running at EL2, the kernel decides to
keep the kernel running at EL2. If another CPU is brought up without
this capability, we use custom hooks (via check_early_cpu_features())
to handle it. To handle such capabilities add support for detecting
and enabling capabilities based on the boot CPU.

A bit is added to indicate if the capability should be detected
early on the boot CPU. The infrastructure then ensures that such
capabilities are probed and "enabled" early on in the boot CPU
and, enabled on the subsequent CPUs.

Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:41 +01:00
Suzuki K Poulose
d3aec8a28b arm64: capabilities: Restrict KPTI detection to boot-time CPUs
KPTI is treated as a system wide feature and is only detected if all
the CPUs in the sysetm needs the defense, unless it is forced via kernel
command line. This leaves a system with a mix of CPUs with and without
the defense vulnerable. Also, if a late CPU needs KPTI but KPTI was not
activated at boot time, the CPU is currently allowed to boot, which is a
potential security vulnerability.
This patch ensures that the KPTI is turned on if at least one CPU detects
the capability (i.e, change scope to SCOPE_LOCAL_CPU). Also rejetcs a late
CPU, if it requires the defense, when the system hasn't enabled it,

Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:40 +01:00
Suzuki K Poulose
5c137714dd arm64: capabilities: Introduce weak features based on local CPU
Now that we have the flexibility of defining system features based
on individual CPUs, introduce CPU feature type that can be detected
on a local SCOPE and ignores the conflict on late CPUs. This is
applicable for ARM64_HAS_NO_HW_PREFETCH, where it is fine for
the system to have CPUs without hardware prefetch turning up
later. We only suffer a performance penalty, nothing fatal.

Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:40 +01:00
Suzuki K Poulose
cce360b54c arm64: capabilities: Filter the entries based on a given mask
While processing the list of capabilities, it is useful to
filter out some of the entries based on the given mask for the
scope of the capabilities to allow better control. This can be
used later for handling LOCAL vs SYSTEM wide capabilities and more.
All capabilities should have their scope set to either LOCAL_CPU or
SYSTEM. No functional/flow change.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:38 +01:00
Suzuki K Poulose
5b4747c5dc arm64: capabilities: Add flags to handle the conflicts on late CPU
When a CPU is brought up, it is checked against the caps that are
known to be enabled on the system (via verify_local_cpu_capabilities()).
Based on the state of the capability on the CPU vs. that of System we
could have the following combinations of conflict.

	x-----------------------------x
	| Type  | System   | Late CPU |
	|-----------------------------|
	|  a    |   y      |    n     |
	|-----------------------------|
	|  b    |   n      |    y     |
	x-----------------------------x

Case (a) is not permitted for caps which are system features, which the
system expects all the CPUs to have (e.g VHE). While (a) is ignored for
all errata work arounds. However, there could be exceptions to the plain
filtering approach. e.g, KPTI is an optional feature for a late CPU as
long as the system already enables it.

Case (b) is not permitted for errata work arounds that cannot be activated
after the kernel has finished booting.And we ignore (b) for features. Here,
yet again, KPTI is an exception, where if a late CPU needs KPTI we are too
late to enable it (because we change the allocation of ASIDs etc).

Add two different flags to indicate how the conflict should be handled.

 ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU - CPUs may have the capability
 ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU - CPUs may not have the cappability.

Now that we have the flags to describe the behavior of the errata and
the features, as we treat them, define types for ERRATUM and FEATURE.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:37 +01:00
Suzuki K Poulose
143ba05d86 arm64: capabilities: Prepare for fine grained capabilities
We use arm64_cpu_capabilities to represent CPU ELF HWCAPs exposed
to the userspace and the CPU hwcaps used by the kernel, which
include cpu features and CPU errata work arounds. Capabilities
have some properties that decide how they should be treated :

 1) Detection, i.e scope : A cap could be "detected" either :
    - if it is present on at least one CPU (SCOPE_LOCAL_CPU)
	Or
    - if it is present on all the CPUs (SCOPE_SYSTEM)

 2) When is it enabled ? - A cap is treated as "enabled" when the
  system takes some action based on whether the capability is detected or
  not. e.g, setting some control register, patching the kernel code.
  Right now, we treat all caps are enabled at boot-time, after all
  the CPUs are brought up by the kernel. But there are certain caps,
  which are enabled early during the boot (e.g, VHE, GIC_CPUIF for NMI)
  and kernel starts using them, even before the secondary CPUs are brought
  up. We would need a way to describe this for each capability.

 3) Conflict on a late CPU - When a CPU is brought up, it is checked
  against the caps that are known to be enabled on the system (via
  verify_local_cpu_capabilities()). Based on the state of the capability
  on the CPU vs. that of System we could have the following combinations
  of conflict.

	x-----------------------------x
	| Type	| System   | Late CPU |
	------------------------------|
	|  a    |   y      |    n     |
	------------------------------|
	|  b    |   n      |    y     |
	x-----------------------------x

  Case (a) is not permitted for caps which are system features, which the
  system expects all the CPUs to have (e.g VHE). While (a) is ignored for
  all errata work arounds. However, there could be exceptions to the plain
  filtering approach. e.g, KPTI is an optional feature for a late CPU as
  long as the system already enables it.

  Case (b) is not permitted for errata work arounds which requires some
  work around, which cannot be delayed. And we ignore (b) for features.
  Here, yet again, KPTI is an exception, where if a late CPU needs KPTI we
  are too late to enable it (because we change the allocation of ASIDs
  etc).

So this calls for a lot more fine grained behavior for each capability.
And if we define all the attributes to control their behavior properly,
we may be able to use a single table for the CPU hwcaps (which cover
errata and features, not the ELF HWCAPs). This is a prepartory step
to get there. More bits would be added for the properties listed above.

We are going to use a bit-mask to encode all the properties of a
capabilities. This patch encodes the "SCOPE" of the capability.

As such there is no change in how the capabilities are treated.

Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:37 +01:00
Suzuki K Poulose
1e89baed5d arm64: capabilities: Move errata processing code
We have errata work around processing code in cpu_errata.c,
which calls back into helpers defined in cpufeature.c. Now
that we are going to make the handling of capabilities
generic, by adding the information to each capability,
move the errata work around specific processing code.
No functional changes.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:01:36 +01:00
Dave Martin
c0cda3b8ee arm64: capabilities: Update prototype for enable call back
We issue the enable() call back for all CPU hwcaps capabilities
available on the system, on all the CPUs. So far we have ignored
the argument passed to the call back, which had a prototype to
accept a "void *" for use with on_each_cpu() and later with
stop_machine(). However, with commit 0a0d111d40
("arm64: cpufeature: Pass capability structure to ->enable callback"),
there are some users of the argument who wants the matching capability
struct pointer where there are multiple matching criteria for a single
capability. Clean up the declaration of the call back to make it clear.

 1) Renamed to cpu_enable(), to imply taking necessary actions on the
    called CPU for the entry.
 2) Pass const pointer to the capability, to allow the call back to
    check the entry. (e.,g to check if any action is needed on the CPU)
 3) We don't care about the result of the call back, turning this to
    a void.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: James Morse <james.morse@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Dave Martin <dave.martin@arm.com>
[suzuki: convert more users, rename call back and drop results]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26 18:00:37 +01:00
Marc Zyngier
33625282ad irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn
We would like to reset the Group-0 Active Priority Registers
at boot time if they are available to us. They would be available
if SCR_EL3.FIQ was not set, but we cannot directly probe this bit,
and short of checking, we may end-up trapping to EL3, and the
firmware may not be please to get such an exception. Yes, this
is dumb.

Instead, let's use PMR to find out if its value gets affected by
SCR_EL3.FIQ being set. We use the fact that when SCR_EL3.FIQ is
set, the LSB of the priority is lost due to the shifting back and
forth of the actual priority. If we read back a 0, we know that
Group0 is unavailable. In case we read a non-zero value, we can
safely reset the AP0Rn register.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-22 13:46:18 +00:00
Dave Martin
af4a81b9cd arm64: fpsimd: Fix bad si_code for undiagnosed SIGFPE
Currently a SIGFPE delivered in response to a floating-point
exception trap may have si_code set to 0 on arm64.  As reported by
Eric, this is a bad idea since this is the value of SI_USER -- yet
this signal is definitely not the result of kill(2), tgkill(2) etc.
and si_uid and si_pid make limited sense whereas we do want to
yield a value for si_addr (which doesn't exist for SI_USER).

It's not entirely clear whether the architecure permits a
"spurious" fp exception trap where none of the exception flag bits
in ESR_ELx is set.  (IMHO the architectural intent is to forbid
this.)  However, it does permit those bits to contain garbage if
the TFV bit in ESR_ELx is 0.  That case isn't currently handled at
all and may result in si_code == 0 or si_code containing a FPE_FLT*
constant corresponding to an exception that did not in fact happen.

There is nothing sensible we can return for si_code in such cases,
but SI_USER is certainly not appropriate and will lead to violation
of legitimate userspace assumptions.

This patch allocates a new si_code value FPE_UNKNOWN that at least
does not conflict with any existing SI_* or FPE_* code, and yields
this in si_code for undiagnosable cases.  This is probably the best
simplicity/incorrectness tradeoff achieveable without relying on
implementation-dependent features or adding a lot of code.  In any
case, there appears to be no perfect solution possible that would
justify a lot of effort here.

Yielding FPE_UNKNOWN when some well-defined fp exception caused the
trap is a violation of POSIX, but this is forced by the
architecture.  We have no realistic prospect of yielding the
correct code in such cases.  At present I am not aware of any ARMv8
implementation that supports trapped floating-point exceptions in
any case.

The new code may be applicable to other architectures for similar
reasons.

No attempt is made to provide ESR_ELx to userspace in the signal
frame, since architectural limitations mean that it is unlikely to
provide much diagnostic value, doesn't benefit existing software
and would create ABI with no proven purpose.  The existing
mechanism for passing it also has problems of its own which may
result in the wrong value being passed to userspace due to
interaction with mm faults.  The implied rework does not appear
justified.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-20 10:03:11 +00:00
Shanker Donthineni
f9f5dc1950 arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening
The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC
V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses
the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead
of Silicon provider service ID 0xC2001700.

Cc: <stable@vger.kernel.org> # 4.14+
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 18:35:38 +00:00
Suzuki K Poulose
7206dc93a5 arm64: Expose Arm v8.4 features
Expose the new features introduced by Arm v8.4 extensions to
Arm v8-A profile.

These include :

 1) Data indpendent timing of instructions. (DIT, exposed as HWCAP_DIT)
 2) Unaligned atomic instructions and Single-copy atomicity of loads
    and stores. (AT, expose as HWCAP_USCAT)
 3) LDAPR and STLR instructions with immediate offsets (extension to
    LRCPC, exposed as HWCAP_ILRCPC)
 4) Flag manipulation instructions (TS, exposed as HWCAP_FLAGM).

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19 18:14:27 +00:00
Ard Biesheuvel
350e1dad0d arm64: asm: drop special versions of adr_l/ldr_l/str_l for modules
Now that we started keeping modules within 4 GB of the core kernel
in all cases, we no longer need to special case the adr_l/ldr_l/str_l
macros for modules to deal with them being loaded farther away.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19 18:14:26 +00:00
Marc Zyngier
dee39247dc arm64: KVM: Allow mapping of vectors outside of the RAM region
We're now ready to map our vectors in weird and wonderful locations.
On enabling ARM64_HARDEN_EL2_VECTORS, a vector slot gets allocated
if this hasn't been already done via ARM64_HARDEN_BRANCH_PREDICTOR
and gets mapped outside of the normal RAM region, next to the
idmap.

That way, being able to obtain VBAR_EL2 doesn't reveal the mapping
of the rest of the hypervisor code.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:06:46 +00:00
Marc Zyngier
4205a89b80 arm64: Make BP hardening slot counter available
We're about to need to allocate hardening slots from other parts
of the kernel (in order to support ARM64_HARDEN_EL2_VECTORS).

Turn the counter into an atomic_t and make it available to the
rest of the kernel. Also add BP_HARDEN_EL2_SLOTS as the number of
slots instead of the hardcoded 4...

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:06:39 +00:00
Marc Zyngier
dc2e4633ff arm/arm64: KVM: Introduce EL2-specific executable mappings
Until now, all EL2 executable mappings were derived from their
EL1 VA. Since we want to decouple the vectors mapping from
the rest of the hypervisor, we need to be able to map some
text somewhere else.

The "idmap" region (for lack of a better name) is ideally suited
for this, as we have a huge range that hardly has anything in it.

Let's extend the IO allocator to also deal with executable mappings,
thus providing the required feature.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:06:05 +00:00
Marc Zyngier
71dcb8be6d arm64: KVM: Allow far branches from vector slots to the main vectors
So far, the branch from the vector slots to the main vectors can at
most be 4GB from the main vectors (the reach of ADRP), and this
distance is known at compile time. If we were to remap the slots
to an unrelated VA, things would break badly.

A way to achieve VA independence would be to load the absolute
address of the vectors (__kvm_hyp_vector), either using a constant
pool or a series of movs, followed by an indirect branch.

This patches implements the latter solution, using another instance
of a patching callback. Note that since we have to save a register
pair on the stack, we branch to the *second* instruction in the
vectors in order to compensate for it. This also results in having
to adjust this balance in the invalid vector entry point.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:06:01 +00:00
Marc Zyngier
4340ba80bd arm64: KVM: Move BP hardening vectors into .hyp.text section
There is no reason why the BP hardening vectors shouldn't be part
of the HYP text at compile time, rather than being mapped at runtime.

Also introduce a new config symbol that controls the compilation
of bpi.S.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:05:49 +00:00
Marc Zyngier
3c5e81232e arm64: KVM: Move vector offsetting from hyp-init.S to kvm_get_hyp_vector
We currently provide the hyp-init code with a kernel VA, and expect
it to turn it into a HYP va by itself. As we're about to provide
the hypervisor with mappings that are not necessarily in the memory
range, let's move the kern_hyp_va macro to kvm_get_hyp_vector.

No functionnal change.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:05:37 +00:00
Marc Zyngier
ed57cac83e arm64: KVM: Introduce EL2 VA randomisation
The main idea behind randomising the EL2 VA is that we usually have
a few spare bits between the most significant bit of the VA mask
and the most significant bit of the linear mapping.

Those bits could be a bunch of zeroes, and could be useful
to move things around a bit. Of course, the more memory you have,
the less randomisation you get...

Alternatively, these bits could be the result of KASLR, in which
case they are already random. But it would be nice to have a
*different* randomization, just to make the job of a potential
attacker a bit more difficult.

Inserting these random bits is a bit involved. We don't have a spare
register (short of rewriting all the kern_hyp_va call sites), and
the immediate we want to insert is too random to be used with the
ORR instruction. The best option I could come up with is the following
sequence:

	and x0, x0, #va_mask
	ror x0, x0, #first_random_bit
	add x0, x0, #(random & 0xfff)
	add x0, x0, #(random >> 12), lsl #12
	ror x0, x0, #(63 - first_random_bit)

making it a fairly long sequence, but one that a decent CPU should
be able to execute without breaking a sweat. It is of course NOPed
out on VHE. The last 4 instructions can also be turned into NOPs
if it appears that there is no free bits to use.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:05:22 +00:00
Marc Zyngier
9f2efa320d arm64; insn: Add encoder for the EXTR instruction
Add an encoder for the EXTR instruction, which also implements the ROR
variant (where Rn == Rm).

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:05:10 +00:00
Marc Zyngier
1bb32a44ae KVM: arm/arm64: Keep GICv2 HYP VAs in kvm_vgic_global_state
As we're about to change the way we map devices at HYP, we need
to move away from kern_hyp_va on an IO address.

One way of achieving this is to store the VAs in kvm_vgic_global_state,
and use that directly from the HYP code. This requires a small change
to create_hyp_io_mappings so that it can also return a HYP VA.

We take this opportunity to nuke the vctrl_base field in the emulated
distributor, as it is not used anymore.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:04:06 +00:00
Marc Zyngier
807a378425 KVM: arm/arm64: Move ioremap calls to create_hyp_io_mappings
Both HYP io mappings call ioremap, followed by create_hyp_io_mappings.
Let's move the ioremap call into create_hyp_io_mappings itself, which
simplifies the code a bit and allows for further refactoring.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:03:47 +00:00
Marc Zyngier
44a497abd6 KVM: arm/arm64: Do not use kern_hyp_va() with kvm_vgic_global_state
kvm_vgic_global_state is part of the read-only section, and is
usually accessed using a PC-relative address generation (adrp + add).

It is thus useless to use kern_hyp_va() on it, and actively problematic
if kern_hyp_va() becomes non-idempotent. On the other hand, there is
no way that the compiler is going to guarantee that such access is
always PC relative.

So let's bite the bullet and provide our own accessor.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:03:33 +00:00
Marc Zyngier
a1efdff442 arm64: cpufeatures: Drop the ARM64_HYP_OFFSET_LOW feature flag
Now that we can dynamically compute the kernek/hyp VA mask, there
is no need for a feature flag to trigger the alternative patching.
Let's drop the flag and everything that depends on it.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:03:31 +00:00
Marc Zyngier
2b4d1606aa arm64: KVM: Dynamically patch the kernel/hyp VA mask
So far, we're using a complicated sequence of alternatives to
patch the kernel/hyp VA mask on non-VHE, and NOP out the
masking altogether when on VHE.

The newly introduced dynamic patching gives us the opportunity
to simplify that code by patching a single instruction with
the correct mask (instead of the mind bending cumulative masking
we have at the moment) or even a single NOP on VHE. This also
adds some initial code that will allow the patching callback
to switch to a more complex patching.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:03:29 +00:00
Marc Zyngier
ef3935eeeb arm64: insn: Add encoder for bitwise operations using literals
We lack a way to encode operations such as AND, ORR, EOR that take
an immediate value. Doing so is quite involved, and is all about
reverse engineering the decoding algorithm described in the
pseudocode function DecodeBitMasks().

This has been tested by feeding it all the possible literal values
and comparing the output with that of GAS.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:03:27 +00:00
Marc Zyngier
a264bf3442 arm64: insn: Add N immediate encoding
We're missing the a way to generate the encoding of the N immediate,
which is only a single bit used in a number of instruction that take
an immediate.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:03:25 +00:00
Marc Zyngier
dea5e2a4c5 arm64: alternatives: Add dynamic patching feature
We've so far relied on a patching infrastructure that only gave us
a single alternative, without any way to provide a range of potential
replacement instructions. For a single feature, this is an all or
nothing thing.

It would be interesting to have a more flexible grained way of patching
the kernel though, where we could dynamically tune the code that gets
injected.

In order to achive this, let's introduce a new form of dynamic patching,
assiciating a callback to a patching site. This callback gets source and
target locations of the patching request, as well as the number of
instructions to be patched.

Dynamic patching is declared with the new ALTERNATIVE_CB and alternative_cb
directives:

	asm volatile(ALTERNATIVE_CB("mov %0, #0\n", callback)
		     : "r" (v));
or
	alternative_cb callback
		mov	x0, #0
	alternative_cb_end

where callback is the C function computing the alternative.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:03:17 +00:00
Christoffer Dall
2d0e63e030 KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs
We can finally get completely rid of any calls to the VGICv3
save/restore functions when the AP lists are empty on VHE systems.  This
requires carefully factoring out trap configuration from saving and
restoring state, and carefully choosing what to do on the VHE and
non-VHE path.

One of the challenges is that we cannot save/restore the VMCR lazily
because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when
emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end
up being delivered as FIQ.

To solve this problem, and still provide fast performance in the fast
path of exiting a VM when no interrupts are pending (which also
optimized the latency for actually delivering virtual interrupts coming
from physical interrupts), we orchestrate a dance of only doing the
activate/deactivate traps in vgic load/put for VHE systems (which can
have ICC_SRE_EL1.SRE cleared when running in the host), and doing the
configuration on every round-trip on non-VHE systems.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:21 +00:00
Christoffer Dall
923a2e30e5 KVM: arm/arm64: Move VGIC APR save/restore to vgic put/load
The APRs can only have bits set when the guest acknowledges an interrupt
in the LR and can only have a bit cleared when the guest EOIs an
interrupt in the LR.  Therefore, if we have no LRs with any
pending/active interrupts, the APR cannot change value and there is no
need to clear it on every exit from the VM (hint: it will have already
been cleared when we exited the guest the last time with the LRs all
EOIed).

The only case we need to take care of is when we migrate the VCPU away
from a CPU or migrate a new VCPU onto a CPU, or when we return to
userspace to capture the state of the VCPU for migration.  To make sure
this works, factor out the APR save/restore functionality into separate
functions called from the VCPU (and by extension VGIC) put/load hooks.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:21 +00:00
Christoffer Dall
75174ba6ca KVM: arm/arm64: Handle VGICv2 save/restore from the main VGIC code
We can program the GICv2 hypervisor control interface logic directly
from the core vgic code and can instead do the save/restore directly
from the flush/sync functions, which can lead to a number of future
optimizations.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:20 +00:00
Christoffer Dall
a2465629b6 KVM: arm64: Configure c15, PMU, and debug register traps on cpu load/put for VHE
We do not have to change the c15 trap setting on each switch to/from the
guest on VHE systems, because this setting only affects guest EL1/EL0
(and therefore not the VHE host).

The PMU and debug trap configuration can also be done on vcpu load/put
instead, because they don't affect how the VHE host kernel can access the
debug registers while executing KVM kernel code.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:19 +00:00
Christoffer Dall
a892819560 KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers
32-bit registers are not used by a 64-bit host kernel and can be
deferred, but we need to rework the accesses to these register to access
the latest values depending on whether or not guest system registers are
loaded on the CPU or only reside in memory.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:18 +00:00
Christoffer Dall
6d4bd90964 KVM: arm64: Prepare to handle deferred save/restore of ELR_EL1
ELR_EL1 is not used by a VHE host kernel and can be deferred, but we
need to rework the accesses to this register to access the latest value
depending on whether or not guest system registers are loaded on the CPU
or only reside in memory.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:17 +00:00
Christoffer Dall
00536ec476 KVM: arm/arm64: Prepare to handle deferred save/restore of SPSR_EL1
SPSR_EL1 is not used by a VHE host kernel and can be deferred, but we
need to rework the accesses to this register to access the latest value
depending on whether or not guest system registers are loaded on the CPU
or only reside in memory.

The handling of accessing the various banked SPSRs for 32-bit VMs is a
bit clunky, but this will be improved in following patches which will
first prepare and subsequently implement deferred save/restore of the
32-bit registers, including the 32-bit SPSRs.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:17 +00:00
Christoffer Dall
d47533dab9 KVM: arm64: Introduce framework for accessing deferred sysregs
We are about to defer saving and restoring some groups of system
registers to vcpu_put and vcpu_load on supported systems.  This means
that we need some infrastructure to access system registes which
supports either accessing the memory backing of the register or directly
accessing the system registers, depending on the state of the system
when we access the register.

We do this by defining read/write accessor functions, which can handle
both "immediate" and "deferrable" system registers.  Immediate registers
are always saved/restored in the world-switch path, but deferrable
registers are only saved/restored in vcpu_put/vcpu_load when supported
and sysregs_loaded_on_cpu will be set in that case.

Note that we don't use the deferred mechanism yet in this patch, but only
introduce infrastructure.  This is to improve convenience of review in
the subsequent patches where it is clear which registers become
deferred.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:17 +00:00
Christoffer Dall
8d404c4c24 KVM: arm64: Rewrite system register accessors to read/write functions
Currently we access the system registers array via the vcpu_sys_reg()
macro.  However, we are about to change the behavior to some times
modify the register file directly, so let's change this to two
primitives:

 * Accessor macros vcpu_write_sys_reg() and vcpu_read_sys_reg()
 * Direct array access macro __vcpu_sys_reg()

The accessor macros should be used in places where the code needs to
access the currently loaded VCPU's state as observed by the guest.  For
example, when trapping on cache related registers, a write to a system
register should go directly to the VCPU version of the register.

The direct array access macro can be used in places where the VCPU is
known to never be running (for example userspace access) or for
registers which are never context switched (for example all the PMU
system registers).

This rewrites all users of vcpu_sys_regs to one of the macros described
above.

No functional change.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:16 +00:00
Christoffer Dall
52f6c4f021 KVM: arm64: Change 32-bit handling of VM system registers
We currently handle 32-bit accesses to trapped VM system registers using
the 32-bit index into the coproc array on the vcpu structure, which is a
union of the coproc array and the sysreg array.

Since all the 32-bit coproc indices are created to correspond to the
architectural mapping between 64-bit system registers and 32-bit
coprocessor registers, and because the AArch64 system registers are the
double in size of the AArch32 coprocessor registers, we can always find
the system register entry that we must update by dividing the 32-bit
coproc index by 2.

This is going to make our lives much easier when we have to start
accessing system registers that use deferred save/restore and might
have to be read directly from the physical CPU.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:16 +00:00
Christoffer Dall
4cdecaba01 KVM: arm64: Unify non-VHE host/guest sysreg save and restore functions
There is no need to have multiple identical functions with different
names for saving host and guest state.  When saving and restoring state
for the host and guest, the state is the same for both contexts, and
that's why we have the kvm_cpu_context structure.  Delete one
version and rename the other into simply save/restore.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:15 +00:00
Christoffer Dall
f837453d0e KVM: arm64: Introduce separate VHE/non-VHE sysreg save/restore functions
As we are about to handle system registers quite differently between VHE
and non-VHE systems.  In preparation for that, we need to split some of
the handling functions between VHE and non-VHE functionality.

For now, we simply copy the non-VHE functions, but we do change the use
of static keys for VHE and non-VHE functionality now that we have
separate functions.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:15 +00:00
Christoffer Dall
3f5c90b890 KVM: arm64: Introduce VHE-specific kvm_vcpu_run
So far this is mostly (see below) a copy of the legacy non-VHE switch
function, but we will start reworking these functions in separate
directions to work on VHE and non-VHE in the most optimal way in later
patches.

The only difference after this patch between the VHE and non-VHE run
functions is that we omit the branch-predictor variant-2 hardening for
QC Falkor CPUs, because this workaround is specific to a series of
non-VHE ARMv8.0 CPUs.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:13 +00:00
Christoffer Dall
014c4c77aa KVM: arm64: Improve debug register save/restore flow
Instead of having multiple calls from the world switch path to the debug
logic, each figuring out if the dirty bit is set and if we should
save/restore the debug registers, let's just provide two hooks to the
debug save/restore functionality, one for switching to the guest
context, and one for switching to the host context, and we get the
benefit of only having to evaluate the dirty flag once on each path,
plus we give the compiler some more room to inline some of this
functionality.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:12 +00:00
Christoffer Dall
e72341c512 KVM: arm/arm64: Introduce vcpu_el1_is_32bit
We have numerous checks around that checks if the HCR_EL2 has the RW bit
set to figure out if we're running an AArch64 or AArch32 VM.  In some
cases, directly checking the RW bit (given its unintuitive name), is a
bit confusing, and that's not going to improve as we move logic around
for the following patches that optimize KVM on AArch64 hosts with VHE.

Therefore, introduce a helper, vcpu_el1_is_32bit, and replace existing
direct checks of HCR_EL2.RW with the helper.

Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:11 +00:00
Christoffer Dall
bc192ceec3 KVM: arm/arm64: Add kvm_vcpu_load_sysregs and kvm_vcpu_put_sysregs
As we are about to move a bunch of save/restore logic for VHE kernels to
the load and put functions, we need some infrastructure to do this.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:11 +00:00
Christoffer Dall
3df59d8dd3 KVM: arm/arm64: Get rid of vcpu->arch.irq_lines
We currently have a separate read-modify-write of the HCR_EL2 on entry
to the guest for the sole purpose of setting the VF and VI bits, if set.
Since this is most rarely the case (only when using userspace IRQ chip
and interrupts are in flight), let's get rid of this operation and
instead modify the bits in the vcpu->arch.hcr[_el2] directly when
needed.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:10 +00:00
Shih-Wei Li
35a84dec00 KVM: arm64: Move HCR_INT_OVERRIDE to default HCR_EL2 guest flag
We always set the IMO and FMO bits in the HCR_EL2 when running the
guest, regardless if we use the vgic or not.  By moving these flags to
HCR_GUEST_FLAGS we can avoid one of the extra save/restore operations of
HCR_EL2 in the world switch code, and we can also soon get rid of the
other one.

This is safe, because even though the IMO and FMO bits control both
taking the interrupts to EL2 and remapping ICC_*_EL1 to ICV_*_EL1 when
executed at EL1, as long as we ensure that these bits are clear when
running the EL1 host, we're OK, because we reset the HCR_EL2 to only
have the HCR_RW bit set when returning to EL1 on non-VHE systems.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:10 +00:00
Christoffer Dall
4464e210de KVM: arm64: Avoid storing the vcpu pointer on the stack
We already have the percpu area for the host cpu state, which points to
the VCPU, so there's no need to store the VCPU pointer on the stack on
every context switch.  We can be a little more clever and just use
tpidr_el2 for the percpu offset and load the VCPU pointer from the host
context.

This has the benefit of being able to retrieve the host context even
when our stack is corrupted, and it has a potential performance benefit
because we trade a store plus a load for an mrs and a load on a round
trip to the guest.

This does require us to calculate the percpu offset without including
the offset from the kernel mapping of the percpu array to the linear
mapping of the array (which is what we store in tpidr_el1), because a
PC-relative generated address in EL2 is already giving us the hyp alias
of the linear mapping of a kernel address.  We do this in
__cpu_init_hyp_mode() by using kvm_ksym_ref().

The code that accesses ESR_EL2 was previously using an alternative to
use the _EL1 accessor on VHE systems, but this was actually unnecessary
as the _EL1 accessor aliases the ESR_EL2 register on VHE, and the _EL2
accessor does the same thing on both systems.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:09 +00:00
Dave Martin
af40ff687b arm64: signal: Ensure si_code is valid for all fault signals
Currently, as reported by Eric, an invalid si_code value 0 is
passed in many signals delivered to userspace in response to faults
and other kernel errors.  Typically 0 is passed when the fault is
insufficiently diagnosable or when there does not appear to be any
sensible alternative value to choose.

This appears to violate POSIX, and is intuitively wrong for at
least two reasons arising from the fact that 0 == SI_USER:

 1) si_code is a union selector, and SI_USER (and si_code <= 0 in
    general) implies the existence of a different set of fields
    (siginfo._kill) from that which exists for a fault signal
    (siginfo._sigfault).  However, the code raising the signal
    typically writes only the _sigfault fields, and the _kill
    fields make no sense in this case.

    Thus when userspace sees si_code == 0 (SI_USER) it may
    legitimately inspect fields in the inactive union member _kill
    and obtain garbage as a result.

    There appears to be software in the wild relying on this,
    albeit generally only for printing diagnostic messages.

 2) Software that wants to be robust against spurious signals may
    discard signals where si_code == SI_USER (or <= 0), or may
    filter such signals based on the si_uid and si_pid fields of
    siginfo._sigkill.  In the case of fault signals, this means
    that important (and usually fatal) error conditions may be
    silently ignored.

In practice, many of the faults for which arm64 passes si_code == 0
are undiagnosable conditions such as exceptions with syndrome
values in ESR_ELx to which the architecture does not yet assign any
meaning, or conditions indicative of a bug or error in the kernel
or system and thus that are unrecoverable and should never occur in
normal operation.

The approach taken in this patch is to translate all such
undiagnosable or "impossible" synchronous fault conditions to
SIGKILL, since these are at least probably localisable to a single
process.  Some of these conditions should really result in a kernel
panic, but due to the lack of diagnostic information it is
difficult to be certain: this patch does not add any calls to
panic(), but this could change later if justified.

Although si_code will not reach userspace in the case of SIGKILL,
it is still desirable to pass a nonzero value so that the common
siginfo handling code can detect incorrect use of si_code == 0
without false positives.  In this case the si_code dependent
siginfo fields will not be correctly initialised, but since they
are not passed to userspace I deem this not to matter.

A few faults can reasonably occur in realistic userspace scenarios,
and _should_ raise a regular, handleable (but perhaps not
ignorable/blockable) signal: for these, this patch attempts to
choose a suitable standard si_code value for the raised signal in
each case instead of 0.

arm64 was the only arch to define a BUS_FIXME code, so after this
patch nobody defines it.  This patch therefore also removes the
relevant code from siginfo_layout().

Cc: James Morse <james.morse@arm.com>
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:58:36 +00:00
Shanker Donthineni
6ae4b6e057 arm64: Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC
The DCache clean & ICache invalidation requirements for instructions
to be data coherence are discoverable through new fields in CTR_EL0.
The following two control bits DIC and IDC were defined for this
purpose. No need to perform point of unification cache maintenance
operations from software on systems where CPU caches are transparent.

This patch optimize the three functions __flush_cache_user_range(),
clean_dcache_area_pou() and invalidate_icache_range() if the hardware
reports CTR_EL0.IDC and/or CTR_EL0.IDC. Basically it skips the two
instructions 'DC CVAU' and 'IC IVAU', and the associated loop logic
in order to avoid the unnecessary overhead.

CTR_EL0.DIC: Instruction cache invalidation requirements for
 instruction to data coherence. The meaning of this bit[29].
  0: Instruction cache invalidation to the point of unification
     is required for instruction to data coherence.
  1: Instruction cache cleaning to the point of unification is
      not required for instruction to data coherence.

CTR_EL0.IDC: Data cache clean requirements for instruction to data
 coherence. The meaning of this bit[28].
  0: Data cache clean to the point of unification is required for
     instruction to data coherence, unless CLIDR_EL1.LoC == 0b000
     or (CLIDR_EL1.LoUIS == 0b000 && CLIDR_EL1.LoUU == 0b000).
  1: Data cache clean to the point of unification is not required
     for instruction to data coherence.

Co-authored-by: Philip Elcan <pelcan@codeaurora.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:57:57 +00:00
Ard Biesheuvel
ca79acca27 arm64/kernel: enable A53 erratum #8434319 handling at runtime
Omit patching of ADRP instruction at module load time if the current
CPUs are not susceptible to the erratum.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: Drop duplicate initialisation of .def_scope field]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:23:09 +00:00
Ard Biesheuvel
e8002e02ab arm64/errata: add REVIDR handling to framework
In some cases, core variants that are affected by a certain erratum
also exist in versions that have the erratum fixed, and this fact is
recorded in a dedicated bit in system register REVIDR_EL1.

Since the architecture does not require that a certain bit retains
its meaning across different variants of the same model, each such
REVIDR bit is tightly coupled to a certain revision/variant value,
and so we need a list of revidr_mask/midr pairs to carry this
information.

So add the struct member and the associated macros and handling to
allow REVIDR fixes to be taken into account.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:23:08 +00:00
Ard Biesheuvel
a257e02579 arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419
Working around Cortex-A53 erratum #843419 involves special handling of
ADRP instructions that end up in the last two instruction slots of a
4k page, or whose output register gets overwritten without having been
read. (Note that the latter instruction sequence is never emitted by
a properly functioning compiler, which is why it is disregarded by the
handling of the same erratum in the bfd.ld linker which we rely on for
the core kernel)

Normally, this gets taken care of by the linker, which can spot such
sequences at final link time, and insert a veneer if the ADRP ends up
at a vulnerable offset. However, linux kernel modules are partially
linked ELF objects, and so there is no 'final link time' other than the
runtime loading of the module, at which time all the static relocations
are resolved.

For this reason, we have implemented the #843419 workaround for modules
by avoiding ADRP instructions altogether, by using the large C model,
and by passing -mpc-relative-literal-loads to recent versions of GCC
that may emit adrp/ldr pairs to perform literal loads. However, this
workaround forces us to keep literal data mixed with the instructions
in the executable .text segment, and literal data may inadvertently
turn into an exploitable speculative gadget depending on the relative
offsets of arbitrary symbols.

So let's reimplement this workaround in a way that allows us to switch
back to the small C model, and to drop the -mpc-relative-literal-loads
GCC switch, by patching affected ADRP instructions at runtime:
- ADRP instructions that do not appear at 4k relative offset 0xff8 or
  0xffc are ignored
- ADRP instructions that are within 1 MB of their target symbol are
  converted into ADR instructions
- remaining ADRP instructions are redirected via a veneer that performs
  the load using an unaffected movn/movk sequence.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: tidied up ADRP -> ADR instruction patching.]
[will: use ULL suffix for 64-bit immediate]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:21:53 +00:00
Ard Biesheuvel
7e611e7dbb efi/arm64: Check whether x18 is preserved by runtime services calls
Whether or not we will ever decide to start using x18 as a platform
register in Linux is uncertain, but by that time, we will need to
ensure that UEFI runtime services calls don't corrupt it.

So let's start issuing warnings now for this, and increase the
likelihood that these firmware images have all been replaced by that time.

This has been fixed on the EDK2 side in commit:

  6d73863b5464 ("BaseTools/tools_def AARCH64: mark register x18 as reserved")

dated July 13, 2017.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180308080020.22828-6-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 08:58:22 +01:00
Will Deacon
e03e61c317 arm64: kaslr: Set TCR_EL1.NFD1 when CONFIG_RANDOMIZE_BASE=y
TCR_EL1.NFD1 was allocated by SVE and ensures that fault-surpressing SVE
memory accesses (e.g. speculative accesses from a first-fault gather load)
which translate via TTBR1_EL1 result in a translation fault if they
miss in the TLB when executed from EL0. This mitigates some timing attacks
against KASLR, where the kernel address space could otherwise be probed
efficiently using the FFR in conjunction with suppressed faults on SVE
loads.

Cc: Dave Martin <Dave.Martin@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:34 +00:00
Catalin Marinas
1f85b42a69 arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)
Commit 9730348075 ("arm64: Increase the max granular size") increased
the cache line size to 128 to match Cavium ThunderX, apparently for some
performance benefit which could not be confirmed. This change, however,
has an impact on the network packets allocation in certain
circumstances, requiring slightly over a 4K page with a significant
performance degradation.

This patch reverts L1_CACHE_SHIFT back to 6 (64-byte cache line) while
keeping ARCH_DMA_MINALIGN at 128. The cache_line_size() function was
changed to default to ARCH_DMA_MINALIGN in the absence of a meaningful
CTR_EL0.CWG bit field.

In addition, if a system with ARCH_DMA_MINALIGN < CTR_EL0.CWG is
detected, the kernel will force swiotlb bounce buffering for all
non-coherent devices since DMA cache maintenance on sub-CWG ranges is
not safe, leading to data corruption.

Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Cc: Timur Tabi <timur@codeaurora.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:32 +00:00
Will Deacon
a26731d9d1 arm64: Move show_unhandled_signals_ratelimited into traps.c
show_unhandled_signals_ratelimited is only called in traps.c, so move it
out of its macro in the dreaded system_misc.h and into a static function
in traps.c

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:31 +00:00
Will Deacon
a1ece8216c arm64: Introduce arm64_force_sig_info and hook up in arm64_notify_die
In preparation for consolidating our handling of printing unhandled
signals, introduce a wrapper around force_sig_info which can act as
the canonical place for dealing with show_unhandled_signals.

Initially, we just hook this up to arm64_notify_die.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:23 +00:00
Will Deacon
2c9120f3a8 arm64: signal: Make force_signal_inject more robust
force_signal_inject is a little flakey:

  * It only knows about SIGILL and SIGSEGV, so can potentially deliver
    other signals based on a partially initialised siginfo_t

  * It sets si_addr to point at the PC for SIGSEGV

  * It always operates on current, so doesn't need the regs argument

This patch fixes these issues by always assigning the si_addr field to
the address parameter of the function and updates the callers (including
those that indirectly call via arm64_notify_segfault) accordingly.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-06 18:52:22 +00:00
Dave Martin
005781be12 arm64: KVM: Move CPU ID reg trap setup off the world switch path
The HCR_EL2.TID3 flag needs to be set when trapping guest access to
the CPU ID registers is required.  However, the decision about
whether to set this bit does not need to be repeated at every
switch to the guest.

Instead, it's sufficient to make this decision once and record the
outcome.

This patch moves the decision to vcpu_reset_hcr() and records the
choice made in vcpu->arch.hcr_el2.  The world switch code can then
load this directly when switching to the guest without the need for
conditional logic on the critical path.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Suggested-by: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-02-26 10:48:01 +01:00
Mark Rutland
cc33c4e201 arm64/kvm: Prohibit guest LOR accesses
We don't currently limit guest accesses to the LOR registers, which we
neither virtualize nor context-switch. As such, guests are provided with
unusable information/controls, and are not isolated from each other (or
the host).

To prevent these issues, we can trap register accesses and present the
illusion LORegions are unssupported by the CPU. To do this, we mask
ID_AA64MMFR1.LO, and set HCR_EL2.TLOR to trap accesses to the following
registers:

* LORC_EL1
* LOREA_EL1
* LORID_EL1
* LORN_EL1
* LORSA_EL1

... when trapped, we inject an UNDEFINED exception to EL1, simulating
their non-existence.

As noted in D7.2.67, when no LORegions are implemented, LoadLOAcquire
and StoreLORelease must behave as LoadAcquire and StoreRelease
respectively. We can ensure this by clearing LORC_EL1.EN when a CPU's
EL2 is first initialized, as the host kernel will not modify this.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-02-26 10:48:01 +01:00