On the Fujitsu-A64FX cores ver(1.0, 1.1), memory access may cause
an undefined fault (Data abort, DFSC=0b111111). This fault occurs under
a specific hardware condition when a load/store instruction performs an
address translation. Any load/store instruction, except non-fault access
including Armv8 and SVE might cause this undefined fault.
The TCR_ELx.NFD1 bit is used by the kernel when CONFIG_RANDOMIZE_BASE
is enabled to mitigate timing attacks against KASLR where the kernel
address space could be probed using the FFR and suppressed fault on
SVE loads.
Since this erratum causes spurious exceptions, which may corrupt
the exception registers, we clear the TCR_ELx.NFDx=1 bits when
booting on an affected CPU.
Signed-off-by: Zhang Lei <zhang.lei@jp.fujitsu.com>
[Generated MIDR value/mask for __cpu_setup(), removed spurious-fault handler
and always disabled the NFDx bits on affected CPUs]
Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The assembly macro get_thread_info() actually returns a task_struct and is
analogous to the current/get_current macro/function.
While it could be argued that thread_info sits at the start of
task_struct and the intention could have been to return a thread_info,
instances of loads from/stores to the address obtained from
get_thread_info() use offsets that are generated with
offsetof(struct task_struct, [...]).
Rename get_thread_info() to state it returns a task_struct.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
KVM/arm updates for Linux v5.1
- A number of pre-nested code rework
- Direct physical timer assignment on VHE systems
- kvm_call_hyp type safety enforcement
- Set/Way cache sanitisation for 32bit guests
- Build system cleanups
- A bunch of janitorial fixes
Since Suzuki K Poulose's work on Dynamic IPA support, KVM_PHYS_SHIFT will
be used only when machine_type's bits[7:0] equal to 0 (by default). Thus
the outdated comment should be fixed.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
On SMP ARM systems, cache maintenance by set/way should only ever be
done in the context of onlining or offlining CPUs, which is typically
done by bare metal firmware and never in a virtual machine. For this
reason, we trap set/way cache maintenance operations and replace them
with conditional flushing of the entire guest address space.
Due to this trapping, the set/way arguments passed into the set/way
ops are completely ignored, and thus irrelevant. This also means that
the set/way geometry is equally irrelevant, and we can simply report
it as 1 set and 1 way, so that legacy 32-bit ARM system software (i.e.,
the kind that only receives odd fixes) doesn't take a performance hit
due to the trapping when iterating over the cachelines.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We currently permit CPUs in the same system to deviate in the exact
topology of the caches, and we subsequently hide this fact from user
space by exposing a sanitised value of the cache type register CTR_EL0.
However, guests running under KVM see the bare value of CTR_EL0, which
could potentially result in issues with, e.g., JITs or other pieces of
code that are sensitive to misreported cache line sizes.
So let's start trapping cache ID instructions if there is a mismatch,
and expose the sanitised version of CTR_EL0 to guests. Note that CTR_EL0
is treated as an invariant to KVM user space, so update that part as well.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Move this little function to the header files for arm/arm64 so other
code can make use of it directly.
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
At the moment we have separate system register emulation handlers for
each timer register. Actually they are quite similar, and we rely on
kvm_arm_timer_[gs]et_reg() for the actual emulation anyways, so let's
just merge all of those handlers into one function, which just marshalls
the arguments and then hands off to a set of common accessors.
This makes extending the emulation to include EL2 timers much easier.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[Fixed 32-bit VM breakage and reduced to reworking existing code]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[Fixed 32bit host, general cleanup]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We previously incorrectly named the define for this system register.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
In preparation for nested virtualization where we are going to have more
than a single VMID per VM, let's factor out the VMID data into a
separate VMID data structure and change the VMID allocator to operate on
this new structure instead of using a struct kvm.
This also means that udate_vttbr now becomes update_vmid, and that the
vttbr itself is generated on the fly based on the stage 2 page table
base address and the vmid.
We cache the physical address of the pgd when allocating the pgd to
avoid doing the calculation on every entry to the guest and to avoid
calling into potentially non-hyp-mapped code from hyp/EL2.
If we wanted to merge the VMID allocator with the arm64 ASID allocator
at some point in the future, it should actually become easier to do that
after this patch.
Note that to avoid mapping the kvm_vmid_bits variable into hyp, we
simply forego the masking of the vmid value in kvm_get_vttbr and rely on
update_vmid to always assign a valid vmid value (within the supported
range).
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
[maz: minor cleanups]
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We currently eagerly save/restore MPIDR. It turns out to be
slightly pointless:
- On the host, this value is known as soon as we're scheduled on a
physical CPU
- In the guest, this value cannot change, as it is set by KVM
(and this is a read-only register)
The result of the above is that we can perfectly avoid the eager
saving of MPIDR_EL1, and only keep the restore. We just have
to setup the host contexts appropriately at boot time.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
When running VHE, there is no need to jump via some stub to perform
a "HYP" function call, as there is a single address space.
Let's thus change kvm_call_hyp() and co to perform a direct call
in this case. Although this results in a bit of code expansion,
it allows the compiler to check for type compatibility, something
that we are missing so far.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Until now, we haven't differentiated between HYP calls that
have a return value and those who don't. As we're about to
change this, introduce kvm_call_hyp_ret(), and change all
call sites that actually make use of a return value.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
After commit cc9f8349cb ("arm64: crypto: add NEON accelerated XOR
implementation"), Clang builds for arm64 started failing with the
following error message.
arch/arm64/lib/xor-neon.c:58:28: error: incompatible pointer types
assigning to 'const unsigned long *' from 'uint64_t *' (aka 'unsigned
long long *') [-Werror,-Wincompatible-pointer-types]
v3 = veorq_u64(vld1q_u64(dp1 + 6), vld1q_u64(dp2 + 6));
^~~~~~~~
/usr/lib/llvm-9/lib/clang/9.0.0/include/arm_neon.h:7538:47: note:
expanded from macro 'vld1q_u64'
__ret = (uint64x2_t) __builtin_neon_vld1q_v(__p0, 51); \
^~~~
There has been quite a bit of debate and triage that has gone into
figuring out what the proper fix is, viewable at the link below, which
is still ongoing. Ard suggested disabling this warning with Clang with a
pragma so no neon code will have this type of error. While this is not
at all an ideal solution, this build error is the only thing preventing
KernelCI from having successful arm64 defconfig and allmodconfig builds
on linux-next. Getting continuous integration running is more important
so new warnings/errors or boot failures can be caught and fixed quickly.
Link: https://github.com/ClangBuiltLinux/linux/issues/283
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Pull EFI fixes from Ingo Molnar:
"This tree reverts a GICv3 commit (which was broken) and fixes it in
another way, by adding a memblock build-time entries quirk for ARM64"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/arm: Revert "Defer persistent reservations until after paging_init()"
arm64, mm, efi: Account for GICv3 LPI tables in static memblock reserve table
In the irqchip and EFI code, we have what basically amounts to a quirk
to work around a peculiarity in the GICv3 architecture, which permits
the system memory address of LPI tables to be programmable only once
after a CPU reset. This means kexec kernels must use the same memory
as the first kernel, and thus ensure that this memory has not been
given out for other purposes by the time the ITS init code runs, which
is not very early for secondary CPUs.
On systems with many CPUs, these reservations could overflow the
memblock reservation table, and this was addressed in commit:
eff8962888 ("efi/arm: Defer persistent reservations until after paging_init()")
However, this turns out to have made things worse, since the allocation
of page tables and heap space for the resized memblock reservation table
itself may overwrite the regions we are attempting to reserve, which may
cause all kinds of corruption, also considering that the ITS will still
be poking bits into that memory in response to incoming MSIs.
So instead, let's grow the static memblock reservation table on such
systems so it can accommodate these reservations at an earlier time.
This will permit us to revert the above commit in a subsequent patch.
[ mingo: Minor cleanups. ]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.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: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190215123333.21209-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
KVM/ARM fixes for 5.0:
- Fix the way we reset vcpus, plugging the race that could happen on VHE
- Fix potentially inconsistent group setting for private interrupts
- Don't generate UNDEF when LORegion feature is present
- Relax the restriction on using stage2 PUD huge mapping
- Turn some spinlocks into raw_spinlocks to help RT compliance
Clang complains when passing asm operands that are smaller than the
registers they are mapped to:
arch/arm64/include/asm/irqflags.h:50:10: warning: value size does not
match register size specified by the constraint and modifier
[-Wasm-operand-widths]
: "r" (GIC_PRIO_IRQON)
Fix it by casting the affected input operands to a type of the correct
size.
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
APEI's Generic Hardware Error Source structures do not describe
whether the SDEI event is shared or private, as this information is
discoverable via the API.
GHES needs to know whether an event is normal or critical to avoid
sharing locks or fixmap entries, but GHES shouldn't have to know about
the SDEI API.
Add a helper to register the GHES using the appropriate normal or
critical callback.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull y2038 - time64 system calls from Arnd Bergmann:
This series finally gets us to the point of having system calls with 64-bit
time_t on all architectures, after a long time of incremental preparation
patches.
There was actually one conversion that I missed during the summer,
i.e. Deepa's timex series, which I now updated based the 5.0-rc1 changes
and review comments.
The following system calls are now added on all 32-bit architectures using
the same system call numbers:
403 clock_gettime64
404 clock_settime64
405 clock_adjtime64
406 clock_getres_time64
407 clock_nanosleep_time64
408 timer_gettime64
409 timer_settime64
410 timerfd_gettime64
411 timerfd_settime64
412 utimensat_time64
413 pselect6_time64
414 ppoll_time64
416 io_pgetevents_time64
417 recvmmsg_time64
418 mq_timedsend_time64
419 mq_timedreceiv_time64
420 semtimedop_time64
421 rt_sigtimedwait_time64
422 futex_time64
423 sched_rr_get_interval_time64
Each one of these corresponds directly to an existing system call that
includes a 'struct timespec' argument, or a structure containing a timespec
or (in case of clock_adjtime) timeval. Not included here are new versions
of getitimer/setitimer and getrusage/waitid, which are planned for the
future but only needed to make a consistent API rather than for correct
operation beyond y2038. These four system calls are based on 'timeval', and
it has not been finally decided what the replacement kernel interface will
use instead.
So far, I have done a lot of build testing across most architectures, which
has found a number of bugs. Runtime testing so far included testing LTP on
32-bit ARM with the existing system calls, to ensure we do not regress for
existing binaries, and a test with a 32-bit x86 build of LTP against a
modified version of the musl C library that has been adapted to the new
system call interface [3]. This library can be used for testing on all
architectures supported by musl-1.1.21, but it is not how the support is
getting integrated into the official musl release. Official musl support is
planned but will require more invasive changes to the library.
Link: https://lore.kernel.org/lkml/20190110162435.309262-1-arnd@arndb.de/T/
Link: https://lore.kernel.org/lkml/20190118161835.2259170-1-arnd@arndb.de/
Link: https://git.linaro.org/people/arnd/musl-y2038.git/ [2]
Pull preparatory work for y2038 changes from Arnd Bergmann:
System call unification and cleanup
The system call tables have diverged a bit over the years, and a number of
the recent additions never made it into all architectures, for one reason
or another.
This is an attempt to clean it up as far as we can without breaking
compatibility, doing a number of steps:
- Add system calls that have not yet been integrated into all architectures
but that we definitely want there. This includes {,f}statfs64() and
get{eg,eu,g,p,u,pp}id() on alpha, which have been missing traditionally.
- The s390 compat syscall handling is cleaned up to be more like what we
do on other architectures, while keeping the 31-bit pointer
extension. This was merged as a shared branch by the s390 maintainers
and is included here in order to base the other patches on top.
- Add the separate ipc syscalls on all architectures that traditionally
only had sys_ipc(). This version is done without support for IPC_OLD
that is we have in sys_ipc. The new semtimedop_time64 syscall will only
be added here, not in sys_ipc
- Add syscall numbers for a couple of syscalls that we probably don't need
everywhere, in particular pkey_* and rseq, for the purpose of symmetry:
if it's in asm-generic/unistd.h, it makes sense to have it everywhere. I
expect that any future system calls will get assigned on all platforms
together, even when they appear to be specific to a single architecture.
- Prepare for having the same system call numbers for any future calls. In
combination with the generated tables, this hopefully makes it easier to
add new calls across all architectures together.
All of the above are technically separate from the y2038 work, but are done
as preparation before we add the new 64-bit time_t system calls everywhere,
providing a common baseline set of system calls.
I expect that glibc and other libraries that want to use 64-bit time_t will
require linux-5.1 kernel headers for building in the future, and at a much
later point may also require linux-5.1 or a later version as the minimum
kernel at runtime. Having a common baseline then allows the removal of many
architecture or kernel version specific workarounds.
Now that ghes notification helpers provide the fixmap slots and
take the lock themselves, multiple NMI-like notifications can
be used on arm64.
These should be named after their notification method as they can't
all be called 'NMI'. x86's NOTIFY_NMI already is, change the SEA
fixmap entry to be called FIX_APEI_GHES_SEA.
Future patches can add support for FIX_APEI_GHES_SEI and
FIX_APEI_GHES_SDEI_{NORMAL,CRITICAL}.
Because all of ghes.c builds on both architectures, provide a
constant for each fixmap entry that the architecture will never
use.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To split up APEIs in_nmi() path, the caller needs to always be
in_nmi(). Add a helper to do the work and claim the notification.
When KVM or the arch code takes an exception that might be a RAS
notification, it asks the APEI firmware-first code whether it wants
to claim the exception. A future kernel-first mechanism may be queried
afterwards, and claim the notification, otherwise we fall through
to the existing default behaviour.
The NOTIFY_SEA code was merged before considering multiple, possibly
interacting, NMI-like notifications and the need to consider kernel
first in the future. Make the 'claiming' behaviour explicit.
Restructuring the APEI code to allow multiple NMI-like notifications
means any notification that might interrupt interrupts-masked
code must always be wrapped in nmi_enter()/nmi_exit(). This will
allow APEI to use in_nmi() to use the right fixmap entries.
Mask SError over this window to prevent an asynchronous RAS error
arriving and tripping 'nmi_enter()'s BUG_ON(in_nmi()).
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To split up APEIs in_nmi() path, the caller needs to always be
in_nmi(). KVM shouldn't have to know about this, pull the RAS plumbing
out into a header file.
Currently guest synchronous external aborts are claimed as RAS
notifications by handle_guest_sea(), which is hidden in the arch codes
mm/fault.c. 32bit gets a dummy declaration in system_misc.h.
There is going to be more of this in the future if/when the kernel
supports the SError-based firmware-first notification mechanism and/or
kernel-first notifications for both synchronous external abort and
SError. Each of these will come with some Kconfig symbols and a
handful of header files.
Create a header file for all this.
This patch gives handle_guest_sea() a 'kvm_' prefix, and moves the
declarations to kvm_ras.h as preparation for a future patch that moves
the ACPI-specific RAS code out of mm/fault.c.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The current kvm_psci_vcpu_on implementation will directly try to
manipulate the state of the VCPU to reset it. However, since this is
not done on the thread that runs the VCPU, we can end up in a strangely
corrupted state when the source and target VCPUs are running at the same
time.
Fix this by factoring out all reset logic from the PSCI implementation
and forwarding the required information along with a request to the
target VCPU.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
This adds 21 new system calls on each ABI that has 32-bit time_t
today. All of these have the exact same semantics as their existing
counterparts, and the new ones all have macro names that end in 'time64'
for clarification.
This gets us to the point of being able to safely use a C library
that has 64-bit time_t in user space. There are still a couple of
loose ends to tie up in various areas of the code, but this is the
big one, and should be entirely uncontroversial at this point.
In particular, there are four system calls (getitimer, setitimer,
waitid, and getrusage) that don't have a 64-bit counterpart yet,
but these can all be safely implemented in the C library by wrapping
around the existing system calls because the 32-bit time_t they
pass only counts elapsed time, not time since the epoch. They
will be dealt with later.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
A lot of system calls that pass a time_t somewhere have an implementation
using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have
been reworked so that this implementation can now be used on 32-bit
architectures as well.
The missing step is to redefine them using the regular SYSCALL_DEFINEx()
to get them out of the compat namespace and make it possible to build them
on 32-bit architectures.
Any system call that ends in 'time' gets a '32' suffix on its name for
that version, while the others get a '_time32' suffix, to distinguish
them from the normal version, which takes a 64-bit time argument in the
future.
In this step, only 64-bit architectures are changed, doing this rename
first lets us avoid touching the 32-bit architectures twice.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Currently alternatives are applied very late in the boot process (and
a long time after we enable scheduling). Some alternative sequences,
such as those that alter the way CPU context is stored, must be applied
much earlier in the boot sequence.
Introduce apply_boot_alternatives() to allow some alternatives to be
applied immediately after we detect the CPU features of the boot CPU.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
[julien.thierry@arm.com: rename to fit new cpufeature framework better,
apply BOOT_SCOPE feature early in boot]
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In preparation for the application of alternatives at different points
during the boot process, provide the possibility to check whether
alternatives for a feature of interest was already applied instead of
having a global boolean for all alternatives.
Make VHE enablement code check for the VHE feature instead of considering
all alternatives.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: Christoffer Dall <Christoffer.Dall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The addition of PMR should not bypass the semantics of daifflags.
When DA_F are set, I bit is also set as no interrupts (even of higher
priority) is allowed.
When DA_F are cleared, I bit is cleared and interrupt enabling/disabling
goes through ICC_PMR_EL1.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Interrupts masked by ICC_PMR_EL1 will not be signaled to the CPU. This
means that hypervisor will not receive masked interrupts while running a
guest.
We need to make sure that all maskable interrupts are masked from the
time we call local_irq_disable() in the main run loop, and remain so
until we call local_irq_enable() after returning from the guest, and we
need to ensure that we see no interrupts at all (including pseudo-NMIs)
in the middle of the VM world-switch, while at the same time we need to
ensure we exit the guest when there are interrupts for the host.
We can accomplish this with pseudo-NMIs enabled by:
(1) local_irq_disable: set the priority mask
(2) enter guest: set PSTATE.I
(3) clear the priority mask
(4) eret to guest
(5) exit guest: set the priotiy mask
clear PSTATE.I (and restore other host PSTATE bits)
(6) local_irq_enable: clear the priority mask.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In order to replace PSR.I interrupt disabling/enabling with ICC_PMR_EL1
interrupt masking, ICC_PMR_EL1 needs to be saved/restored when
taking/returning from an exception. This mimics the way hardware saves
and restores PSR.I bit in spsr_el1 for exceptions and ERET.
Add PMR to the registers to save in the pt_regs struct upon kernel entry,
and restore it before ERET. Also, initialize it to a sane value when
creating new tasks.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When using VHE, the host needs to clear HCR_EL2.TGE bit in order
to interact with guest TLBs, switching from EL2&0 translation regime
to EL1&0.
However, some non-maskable asynchronous event could happen while TGE is
cleared like SDEI. Because of this address translation operations
relying on EL2&0 translation regime could fail (tlb invalidation,
userspace access, ...).
Fix this by properly setting HCR_EL2.TGE when entering NMI context and
clear it if necessary when returning to the interrupted context.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The behavior of these system calls is slightly different between
architectures, as determined by the CONFIG_ARCH_WANT_IPC_PARSE_VERSION
symbol. Most architectures that implement the split IPC syscalls don't set
that symbol and only get the modern version, but alpha, arm, microblaze,
mips-n32, mips-n64 and xtensa expect the caller to pass the IPC_64 flag.
For the architectures that so far only implement sys_ipc(), i.e. m68k,
mips-o32, powerpc, s390, sh, sparc, and x86-32, we want the new behavior
when adding the split syscalls, so we need to distinguish between the
two groups of architectures.
The method I picked for this distinction is to have a separate system call
entry point: sys_old_*ctl() now uses ipc_parse_version, while sys_*ctl()
does not. The system call tables of the five architectures are changed
accordingly.
As an additional benefit, we no longer need the configuration specific
definition for ipc_parse_version(), it always does the same thing now,
but simply won't get called on architectures with the modern interface.
A small downside is that on architectures that do set
ARCH_WANT_IPC_PARSE_VERSION, we now have an extra set of entry points
that are never called. They only add a few bytes of bloat, so it seems
better to keep them compared to adding yet another Kconfig symbol.
I considered adding new syscall numbers for the IPC_64 variants for
consistency, but decided against that for now.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
A couple of architectures including arm64 already implement the
kexec_file_load system call, on many others we have assigned a system
call number for it, but not implemented it yet.
Adding the number in arch/arm/ lets us use the system call on arm64
systems in compat mode, and also reduces the number of differences
between architectures. If we want to implement kexec_file_load on ARM
in the future, the number assignment means that kexec tools can already
be built with the now current set of kernel headers.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The migrate_pages system call has an assigned number on all architectures
except ARM. When it got added initially in commit d80ade7b32 ("ARM:
Fix warning: #warning syscall migrate_pages not implemented"), it was
intentionally left out based on the observation that there are no 32-bit
ARM NUMA systems.
However, there are now arm64 NUMA machines that can in theory run 32-bit
kernels (actually enabling NUMA there would require additional work)
as well as 32-bit user space on 64-bit kernels, so that argument is no
longer very strong.
Assigning the number lets us use the system call on 64-bit kernels as well
as providing a more consistent set of syscalls across architectures.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Current implementation of get/put_user_unsafe default to get/put_user
which toggle PAN before each access, despite having been told by the caller
that multiple accesses to user memory were about to happen.
Provide implementations for user_access_begin/end to turn PAN off/on and
implement unsafe accessors that assume PAN was already turned off.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
