Commit Graph

99 Commits

Author SHA1 Message Date
Linus Torvalds
6a447b0e31 ARM:
* PSCI relay at EL2 when "protected KVM" is enabled
 * New exception injection code
 * Simplification of AArch32 system register handling
 * Fix PMU accesses when no PMU is enabled
 * Expose CSV3 on non-Meltdown hosts
 * Cache hierarchy discovery fixes
 * PV steal-time cleanups
 * Allow function pointers at EL2
 * Various host EL2 entry cleanups
 * Simplification of the EL2 vector allocation
 
 s390:
 * memcg accouting for s390 specific parts of kvm and gmap
 * selftest for diag318
 * new kvm_stat for when async_pf falls back to sync
 
 x86:
 * Tracepoints for the new pagetable code from 5.10
 * Catch VFIO and KVM irqfd events before userspace
 * Reporting dirty pages to userspace with a ring buffer
 * SEV-ES host support
 * Nested VMX support for wait-for-SIPI activity state
 * New feature flag (AVX512 FP16)
 * New system ioctl to report Hyper-V-compatible paravirtualization features
 
 Generic:
 * Selftest improvements
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "Much x86 work was pushed out to 5.12, but ARM more than made up for it.

  ARM:
   - PSCI relay at EL2 when "protected KVM" is enabled
   - New exception injection code
   - Simplification of AArch32 system register handling
   - Fix PMU accesses when no PMU is enabled
   - Expose CSV3 on non-Meltdown hosts
   - Cache hierarchy discovery fixes
   - PV steal-time cleanups
   - Allow function pointers at EL2
   - Various host EL2 entry cleanups
   - Simplification of the EL2 vector allocation

  s390:
   - memcg accouting for s390 specific parts of kvm and gmap
   - selftest for diag318
   - new kvm_stat for when async_pf falls back to sync

  x86:
   - Tracepoints for the new pagetable code from 5.10
   - Catch VFIO and KVM irqfd events before userspace
   - Reporting dirty pages to userspace with a ring buffer
   - SEV-ES host support
   - Nested VMX support for wait-for-SIPI activity state
   - New feature flag (AVX512 FP16)
   - New system ioctl to report Hyper-V-compatible paravirtualization features

  Generic:
   - Selftest improvements"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits)
  KVM: SVM: fix 32-bit compilation
  KVM: SVM: Add AP_JUMP_TABLE support in prep for AP booting
  KVM: SVM: Provide support to launch and run an SEV-ES guest
  KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
  KVM: SVM: Provide support for SEV-ES vCPU loading
  KVM: SVM: Provide support for SEV-ES vCPU creation/loading
  KVM: SVM: Update ASID allocation to support SEV-ES guests
  KVM: SVM: Set the encryption mask for the SVM host save area
  KVM: SVM: Add NMI support for an SEV-ES guest
  KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest
  KVM: SVM: Do not report support for SMM for an SEV-ES guest
  KVM: x86: Update __get_sregs() / __set_sregs() to support SEV-ES
  KVM: SVM: Add support for CR8 write traps for an SEV-ES guest
  KVM: SVM: Add support for CR4 write traps for an SEV-ES guest
  KVM: SVM: Add support for CR0 write traps for an SEV-ES guest
  KVM: SVM: Add support for EFER write traps for an SEV-ES guest
  KVM: SVM: Support string IO operations for an SEV-ES guest
  KVM: SVM: Support MMIO for an SEV-ES guest
  KVM: SVM: Create trace events for VMGEXIT MSR protocol processing
  KVM: SVM: Create trace events for VMGEXIT processing
  ...
2020-12-20 10:44:05 -08:00
Marc Zyngier
9fd339a45b arm64: Work around broken GCC 4.9 handling of "S" constraint
GCC 4.9 seems to have a problem with the "S" asm constraint
when the symbol lives in the same compilation unit, and pretends
the constraint is impossible:

$ cat x.c
void *foo(void)
{
	static int x;
	int *addr;
	asm("adrp %0, %1" : "=r" (addr) : "S" (&x));
	return addr;
}

$ ~/Work/gcc-linaro-aarch64-linux-gnu-4.9-2014.09_linux/bin/aarch64-linux-gnu-gcc -S -x c -O2 x.c
x.c: In function ‘foo’:
x.c:5:2: error: impossible constraint in ‘asm’
  asm("adrp %0, %1" : "=r" (addr) : "S" (&x));
  ^

Boo. Following revisions of the compiler work just fine, though.

We can fallback to the "i" constraint for GCC version prior to 5.0,
which *seems* to do the right thing. Hopefully we will be able to
remove this at some point, but in the meantime this gets us going.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20201217111135.1536658-1-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-17 11:46:20 +00:00
Marc Zyngier
3a514592b6 Merge remote-tracking branch 'origin/kvm-arm64/psci-relay' into kvmarm-master/next
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-12-09 10:00:24 +00:00
David Brazdil
d3e1086c64 KVM: arm64: Init MAIR/TCR_EL2 from params struct
MAIR_EL2 and TCR_EL2 are currently initialized from their _EL1 values.
This will not work once KVM starts intercepting PSCI ON/SUSPEND SMCs
and initializing EL2 state before EL1 state.

Obtain the EL1 values during KVM init and store them in the init params
struct. The struct will stay in memory and can be used when booting new
cores.

Take the opportunity to move copying the T0SZ value from idmap_t0sz in
KVM init rather than in .hyp.idmap.text. This avoids the need for the
idmap_t0sz symbol alias.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-12-dbrazdil@google.com
2020-12-04 10:08:33 +00:00
David Brazdil
63fec24351 KVM: arm64: Move hyp-init params to a per-CPU struct
Once we start initializing KVM on newly booted cores before the rest of
the kernel, parameters to __do_hyp_init will need to be provided by EL2
rather than EL1. At that point it will not be possible to pass its three
arguments directly because PSCI_CPU_ON only supports one context
argument.

Refactor __do_hyp_init to accept its parameters in a struct. This
prepares the code for KVM booting cores as well as removes any limits on
the number of __do_hyp_init arguments.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-11-dbrazdil@google.com
2020-12-04 10:08:32 +00:00
David Brazdil
5be1d6226d KVM: arm64: Remove vector_ptr param of hyp-init
KVM precomputes the hyp VA of __kvm_hyp_host_vector, essentially a
constant (minus ASLR), before passing it to __kvm_hyp_init.
Now that we have alternatives for converting kimg VA to hyp VA, replace
this with computing the constant inside __kvm_hyp_init, thus removing
the need for an argument.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-10-dbrazdil@google.com
2020-12-04 10:08:32 +00:00
Marc Zyngier
dc2286f397 Merge branch 'kvm-arm64/vector-rework' into kvmarm-master/next
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-27 11:47:08 +00:00
Marc Zyngier
29052f1b92 KVM: arm64: Simplify __kvm_enable_ssbs()
Move the setting of SSBS directly into the HVC handler, using
the C helpers rather than the inline asssembly code.

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-27 11:32:44 +00:00
Will Deacon
b881cdce77 KVM: arm64: Allocate hyp vectors statically
The EL2 vectors installed when a guest is running point at one of the
following configurations for a given CPU:

  - Straight at __kvm_hyp_vector
  - A trampoline containing an SMC sequence to mitigate Spectre-v2 and
    then a direct branch to __kvm_hyp_vector
  - A dynamically-allocated trampoline which has an indirect branch to
    __kvm_hyp_vector
  - A dynamically-allocated trampoline containing an SMC sequence to
    mitigate Spectre-v2 and then an indirect branch to __kvm_hyp_vector

The indirect branches mean that VA randomization at EL2 isn't trivially
bypassable using Spectre-v3a (where the vector base is readable by the
guest).

Rather than populate these vectors dynamically, configure everything
statically and use an enumerated type to identify the vector "slot"
corresponding to one of the configurations above. This both simplifies
the code, but also makes it much easier to implement at EL2 later on.

Signed-off-by: Will Deacon <will@kernel.org>
[maz: fixed double call to kvm_init_vector_slots() on nVHE]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20201113113847.21619-8-will@kernel.org
2020-11-16 10:43:05 +00:00
Marc Zyngier
14ef9d0492 Merge branch 'kvm-arm64/hyp-pcpu' into kvmarm-master/next
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-30 14:05:35 +01:00
Marc Zyngier
816c347f3a Merge remote-tracking branch 'arm64/for-next/ghostbusters' into kvm-arm64/hyp-pcpu
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-30 09:48:30 +01:00
David Brazdil
30c953911c kvm: arm64: Set up hyp percpu data for nVHE
Add hyp percpu section to linker script and rename the corresponding ELF
sections of hyp/nvhe object files. This moves all nVHE-specific percpu
variables to the new hyp percpu section.

Allocate sufficient amount of memory for all percpu hyp regions at global KVM
init time and create corresponding hyp mappings.

The base addresses of hyp percpu regions are kept in a dynamically allocated
array in the kernel.

Add NULL checks in PMU event-reset code as it may run before KVM memory is
initialized.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-10-dbrazdil@google.com
2020-09-30 08:37:14 +01:00
David Brazdil
572494995b kvm: arm64: Add helpers for accessing nVHE hyp per-cpu vars
Defining a per-CPU variable in hyp/nvhe will result in its name being
prefixed with __kvm_nvhe_. Add helpers for declaring these variables
in kernel proper and accessing them with this_cpu_ptr and per_cpu_ptr.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-7-dbrazdil@google.com
2020-09-30 08:37:13 +01:00
David Brazdil
ea391027d3 kvm: arm64: Remove hyp_adr/ldr_this_cpu
The hyp_adr/ldr_this_cpu helpers were introduced for use in hyp code
because they always needed to use TPIDR_EL2 for base, while
adr/ldr_this_cpu from kernel proper would select between TPIDR_EL2 and
_EL1 based on VHE/nVHE.

Simplify this now that the hyp mode case can be handled using the
__KVM_VHE/NVHE_HYPERVISOR__ macros.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Andrew Scull <ascull@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-6-dbrazdil@google.com
2020-09-30 08:37:07 +01:00
David Brazdil
717cf94adb kvm: arm64: Remove __hyp_this_cpu_read
this_cpu_ptr is meant for use in kernel proper because it selects between
TPIDR_EL1/2 based on nVHE/VHE. __hyp_this_cpu_ptr was used in hyp to always
select TPIDR_EL2. Unify all users behind this_cpu_ptr and friends by
selecting _EL2 register under __KVM_NVHE_HYPERVISOR__. VHE continues
selecting the register using alternatives.

Under CONFIG_DEBUG_PREEMPT, the kernel helpers perform a preemption check
which is omitted by the hyp helpers. Preserve the behavior for nVHE by
overriding the corresponding macros under __KVM_NVHE_HYPERVISOR__. Extend
the checks into VHE hyp code.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Andrew Scull <ascull@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-5-dbrazdil@google.com
2020-09-30 08:33:52 +01:00
David Brazdil
ce492a16ff kvm: arm64: Move nVHE hyp namespace macros to hyp_image.h
Minor cleanup to move all macros related to prefixing nVHE hyp section
and symbol names into one place: hyp_image.h.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-3-dbrazdil@google.com
2020-09-30 08:33:52 +01:00
Will Deacon
9ef2b48be9 KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabled
Patching the EL2 exception vectors is integral to the Spectre-v2
workaround, where it can be necessary to execute CPU-specific sequences
to nobble the branch predictor before running the hypervisor text proper.

Remove the dependency on CONFIG_RANDOMIZE_BASE and allow the EL2 vectors
to be patched even when KASLR is not enabled.

Fixes: 7a132017e7a5 ("KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202009221053.Jv1XsQUZ%lkp@intel.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:17 +01:00
Marc Zyngier
29e8910a56 KVM: arm64: Simplify handling of ARCH_WORKAROUND_2
Owing to the fact that the host kernel is always mitigated, we can
drastically simplify the WA2 handling by keeping the mitigation
state ON when entering the guest. This means the guest is either
unaffected or not mitigated.

This results in a nice simplification of the mitigation space,
and the removal of a lot of code that was never really used anyway.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:16 +01:00
Will Deacon
5359a87d5b KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE
The removal of CONFIG_HARDEN_BRANCH_PREDICTOR means that
CONFIG_KVM_INDIRECT_VECTORS is synonymous with CONFIG_RANDOMIZE_BASE,
so replace it.

Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29 16:08:15 +01:00
Andrew Scull
054698316d KVM: arm64: nVHE: Migrate hyp interface to SMCCC
Rather than passing arbitrary function pointers to run at hyp, define
and equivalent set of SMCCC functions.

Since the SMCCC functions are strongly tied to the original function
prototypes, it is not expected for the host to ever call an invalid ID
but a warning is raised if this does ever occur.

As __kvm_vcpu_run is used for every switch between the host and a guest,
it is explicitly singled out to be identified before the other function
IDs to improve the performance of the hot path.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-18-ascull@google.com
2020-09-15 18:39:04 +01:00
Andrew Scull
603d2bdaa5 KVM: arm64: Share context save and restore macros
To avoid duplicating the context save and restore macros, move them into
a shareable header.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-12-ascull@google.com
2020-09-15 18:39:03 +01:00
Andrew Scull
7db2153047 KVM: arm64: Restore hyp when panicking in guest context
If the guest context is loaded when a panic is triggered, restore the
hyp context so e.g. the shadow call stack works when hyp_panic() is
called and SP_EL0 is valid when the host's panic() is called.

Use the hyp context's __hyp_running_vcpu field to track when hyp
transitions to and from the guest vcpu so the exception handlers know
whether the context needs to be restored.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-11-ascull@google.com
2020-09-15 18:39:02 +01:00
Andrew Scull
6e3bfbb22c KVM: arm64: nVHE: Use separate vector for the host
The host is treated differently from the guests when an exception is
taken so introduce a separate vector that is specialized for the host.
This also allows the nVHE specific code to move out of hyp-entry.S and
into nvhe/host.S.

The host is only expected to make HVC calls and anything else is
considered invalid and results in a panic.

Hyp initialization is now passed the vector that is used for the host
and it is swapped for the guest vector during the context switch.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-7-ascull@google.com
2020-09-15 18:39:02 +01:00
Andrew Scull
ceee2fe4ba KVM: arm64: Choose hyp symbol based on context
Make CHOOSE_HYP_SYM select the symbol of the active hypervisor for the
host, the nVHE symbol for nVHE and the VHE symbol for VHE. The nVHE and
VHE hypervisors see their own symbols without prefixes and trigger a
link error when trying to use a symbol of the other hypervisor.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: David Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20200915104643.2543892-5-ascull@google.com
2020-09-15 18:39:01 +01:00
James Morse
88a84ccccb KVM: arm64: Survive synchronous exceptions caused by AT instructions
KVM doesn't expect any synchronous exceptions when executing, any such
exception leads to a panic(). AT instructions access the guest page
tables, and can cause a synchronous external abort to be taken.

The arm-arm is unclear on what should happen if the guest has configured
the hardware update of the access-flag, and a memory type in TCR_EL1 that
does not support atomic operations. B2.2.6 "Possible implementation
restrictions on using atomic instructions" from DDI0487F.a lists
synchronous external abort as a possible behaviour of atomic instructions
that target memory that isn't writeback cacheable, but the page table
walker may behave differently.

Make KVM robust to synchronous exceptions caused by AT instructions.
Add a get_user() style helper for AT instructions that returns -EFAULT
if an exception was generated.

While KVM's version of the exception table mixes synchronous and
asynchronous exceptions, only one of these can occur at each location.

Re-enter the guest when the AT instructions take an exception on the
assumption the guest will take the same exception. This isn't guaranteed
to make forward progress, as the AT instructions may always walk the page
tables, but guest execution may use the translation cached in the TLB.

This isn't a problem, as since commit 5dcd0fdbb4 ("KVM: arm64: Defer guest
entry when an asynchronous exception is pending"), KVM will return to the
host to process IRQs allowing the rest of the system to keep running.

Cc: stable@vger.kernel.org # <v5.3: 5dcd0fdbb4 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending")
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28 15:23:46 +01:00
James Morse
e9ee186bb7 KVM: arm64: Add kvm_extable for vaxorcism code
KVM has a one instruction window where it will allow an SError exception
to be consumed by the hypervisor without treating it as a hypervisor bug.
This is used to consume asynchronous external abort that were caused by
the guest.

As we are about to add another location that survives unexpected exceptions,
generalise this code to make it behave like the host's extable.

KVM's version has to be mapped to EL2 to be accessible on nVHE systems.

The SError vaxorcism code is a one instruction window, so has two entries
in the extable. Because the KVM code is copied for VHE and nVHE, we end up
with four entries, half of which correspond with code that isn't mapped.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28 15:23:42 +01:00
Marc Zyngier
a394cf6e85 Merge branch 'kvm-arm64/misc-5.9' into kvmarm-master/next-WIP
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-28 16:26:16 +01:00
Marc Zyngier
300dca6853 Merge branch 'kvm-arm64/pre-nv-5.9' into kvmarm-master/next-WIP
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-28 15:48:27 +01:00
Marc Zyngier
6de7dd31de KVM: arm64: Don't use has_vhe() for CHOOSE_HYP_SYM()
The recently introduced CHOOSE_HYP_SYM() macro picks one symbol
or another, depending on whether the kernel run as a VHE
hypervisor or not. For that, it uses the has_vhe() helper, which
is itself implemented as a final capability.

Unfortunately, __copy_hyp_vect_bpi now indirectly uses CHOOSE_HYP_SYM
to get the __bp_harden_hyp_vecs symbol, using has_vhe() in the process.
At this stage, the capability isn't final and things explode:

[    0.000000] ACPI: SRAT not present
[    0.000000] percpu: Embedded 34 pages/cpu s101264 r8192 d29808 u139264
[    0.000000] Detected PIPT I-cache on CPU0
[    0.000000] ------------[ cut here ]------------
[    0.000000] kernel BUG at arch/arm64/include/asm/cpufeature.h:459!
[    0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00080-gd630681366e5 #1388
[    0.000000] pstate: 80000085 (Nzcv daIf -PAN -UAO BTYPE=--)
[    0.000000] pc : check_branch_predictor+0x3a4/0x408
[    0.000000] lr : check_branch_predictor+0x2a4/0x408
[    0.000000] sp : ffff800011693e90
[    0.000000] x29: ffff800011693e90 x28: ffff8000116a1530
[    0.000000] x27: ffff8000112c1008 x26: ffff800010ca6ff8
[    0.000000] x25: ffff8000112c1000 x24: ffff8000116a1320
[    0.000000] x23: 0000000000000000 x22: ffff8000112c1000
[    0.000000] x21: ffff800010177120 x20: ffff8000116ae108
[    0.000000] x19: 0000000000000000 x18: ffff800011965c90
[    0.000000] x17: 0000000000022000 x16: 0000000000000003
[    0.000000] x15: 00000000ffffffff x14: ffff8000118c3a38
[    0.000000] x13: 0000000000000021 x12: 0000000000000022
[    0.000000] x11: d37a6f4de9bd37a7 x10: 000000000000001d
[    0.000000] x9 : 0000000000000000 x8 : ffff800011f8dad8
[    0.000000] x7 : ffff800011965ad0 x6 : 0000000000000003
[    0.000000] x5 : 0000000000000000 x4 : 0000000000000000
[    0.000000] x3 : 0000000000000100 x2 : 0000000000000004
[    0.000000] x1 : ffff8000116ae148 x0 : 0000000000000000
[    0.000000] Call trace:
[    0.000000]  check_branch_predictor+0x3a4/0x408
[    0.000000]  update_cpu_capabilities+0x84/0x138
[    0.000000]  init_cpu_features+0x2c0/0x2d8
[    0.000000]  cpuinfo_store_boot_cpu+0x54/0x64
[    0.000000]  smp_prepare_boot_cpu+0x2c/0x60
[    0.000000]  start_kernel+0x16c/0x574
[    0.000000] Code: 17ffffc7 91010281 14000198 17ffffca (d4210000)

This is addressed using a two-fold process:
- Replace has_vhe() with is_kernel_in_hyp_mode(), which tests
  whether we are running at EL2.
- Make CHOOSE_HYP_SYM() return an *undefined* symbol when
  compiled in the nVHE hypervisor, as we really should never
  use this helper in the nVHE-specific code.

With this in place, we're back to a bootable kernel again.

Fixes: b877e9849d ("KVM: arm64: Build hyp-entry.S separately for VHE/nVHE")
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 18:01:22 +01:00
Marc Zyngier
efaa5b93af KVM: arm64: Use TTL hint in when invalidating stage-2 translations
Since we often have a precise idea of the level we're dealing with
when invalidating TLBs, we can provide it to as a hint to our
invalidation helper.

Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:37 +01:00
Christoffer Dall
a0e50aa3f4 KVM: arm64: Factor out stage 2 page table data from struct kvm
As we are about to reuse our stage 2 page table manipulation code for
shadow stage 2 page tables in the context of nested virtualization, we
are going to manage multiple stage 2 page tables for a single VM.

This requires some pretty invasive changes to our data structures,
which moves the vmid and pgd pointers into a separate structure and
change pretty much all of our mmu code to operate on this structure
instead.

The new structure is called struct kvm_s2_mmu.

There is no intended functional change by this patch alone.

Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
[Designed data structure layout in collaboration]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
[maz: Moved the last_vcpu_ran down to the S2 MMU structure as well]
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:37 +01:00
David Brazdil
09cf57eba3 KVM: arm64: Split hyp/switch.c to VHE/nVHE
switch.c implements context-switching for KVM, with large parts shared between
VHE/nVHE. These common routines are moved to a header file, VHE-specific code
is moved to vhe/switch.c and nVHE-specific code is moved to nvhe/switch.c.

Previously __kvm_vcpu_run needed a different symbol name for VHE/nVHE. This
is cleaned up and the caller in arm.c simplified.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-10-dbrazdil@google.com
2020-07-05 18:38:21 +01:00
Andrew Scull
208243c752 KVM: arm64: Move hyp-init.S to nVHE
hyp-init.S contains the identity mapped initialisation code for the
non-VHE code that runs at EL2. It is only used for non-VHE.

Adjust code that calls into this to use the prefixed symbol name.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-8-dbrazdil@google.com
2020-07-05 18:38:12 +01:00
David Brazdil
b877e9849d KVM: arm64: Build hyp-entry.S separately for VHE/nVHE
hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly
shared between VHE/nVHE, therefore compile it under both VHE and nVHE build
rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__.

Adjust code which selects which KVM hyp vecs to install to choose the correct
VHE/nVHE symbol.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-07-05 18:38:08 +01:00
Andrew Scull
f50b6f6ae1 KVM: arm64: Handle calls to prefixed hyp functions
Once hyp functions are moved to a hyp object, they will have prefixed symbols.
This change declares and gets the address of the prefixed version for calls to
the hyp functions.

To aid migration, the hyp functions that have not yet moved have their prefixed
versions aliased to their non-prefixed version. This begins with all the hyp
functions being listed and will reduce to none of them once the migration is
complete.

Signed-off-by: Andrew Scull <ascull@google.com>

[David: Extracted kvm_call_hyp nVHE branches into own helper macros, added
        comments around symbol aliases.]

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-6-dbrazdil@google.com
2020-07-05 18:38:04 +01:00
Andrew Scull
2da3ffa6e8 arm64: kvm: Remove kern_hyp_va from get_vcpu_ptr
get_vcpu_ptr is an assembly accessor for the percpu value
kvm_host_data->host_ctxt.__hyp_running_vcpu. kern_hyp_va only applies to
nVHE however __hyp_running_vcpu is always assigned a pointer that has
already had kern_hyp_va applied in __kvm_vcpu_run_nvhe.

kern_hyp_va is currently idempotent as it just masks and inserts the
tag, but this could change in future and the second application is
unnecessary.

Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200618093616.164413-1-ascull@google.com
2020-07-05 18:02:36 +01:00
Marc Zyngier
304e2989c9 KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h
Recent refactoring of the arm64 code make it awkward to have
hyp_symbol_addr() in kvm_mmu.h. Instead, move it next to its
main user, which is __hyp_this_cpu_ptr().

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-10 19:09:09 +01:00
Marc Zyngier
b990d37fdf KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr
Sparse complains that __hyp_this_cpu_ptr() returns something
that is flagged noderef and not in the correct address space
(both being the result of the __percpu annotation).

Pretend that __hyp_this_cpu_ptr() knows what it is doing by
forcefully casting the pointer with __kernel __force.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-09 10:59:52 +01:00
David Brazdil
71b3ec5f22 KVM: arm64: Clean up cpu_init_hyp_mode()
Pull bits of code to the only place where it is used. Remove empty function
__cpu_init_stage2(). Remove redundant has_vhe() check since this function is
nVHE-only. No functional changes intended.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200515152056.83158-1-dbrazdil@google.com
2020-05-25 16:15:47 +01:00
Marc Zyngier
c6fe89ff8b KVM: arm64: Simplify __kvm_timer_set_cntvoff implementation
Now that this function isn't constrained by the 32bit PCS,
let's simplify it by taking a single 64bit offset instead
of two 32bit parameters.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-05-16 15:04:18 +01:00
Mark Brown
4db61fef16 arm64: kvm: Modernize __smccc_workaround_1_smc_start annotations
In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC with separate annotations for standard C callable functions,
data and code with different calling conventions.

Using these for __smccc_workaround_1_smc is more involved than for most
symbols as this symbol is annotated quite unusually, rather than just have
the explicit symbol we define _start and _end symbols which we then use to
compute the length. This does not play at all nicely with the new style
macros. Instead define a constant for the size of the function and use that
in both the C code and for .org based size checks in the assembly code.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
2020-03-09 17:35:43 +00:00
James Morse
0e5b9c085d KVM: arm64: Consume pending SError as early as possible
On systems with v8.2 we switch the 'vaxorcism' of guest SError with an
alternative sequence that uses the ESB-instruction, then reads DISR_EL1.
This saves the unmasking and remasking of asynchronous exceptions.

We do this after we've saved the guest registers and restored the
host's. Any SError that becomes pending due to this will be accounted
to the guest, when it actually occurred during host-execution.

Move the ESB-instruction as early as possible. Any guest SError
will become pending due to this ESB-instruction and then consumed to
DISR_EL1 before the host touches anything.

This lets us account for host/guest SError precisely on the guest
exit exception boundary.

Because the ESB-instruction now lands in the preamble section of
the vectors, we need to add it to the unpatched indirect vectors
too, and to any sequence that may be patched in over the top.

The ESB-instruction always lives in the head of the vectors,
to be before any memory write. Whereas the register-store always
lives in the tail.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:29 +01:00
James Morse
3dbf100b0b KVM: arm64: Abstract the size of the HYP vectors pre-amble
The EL2 vector hardening feature causes KVM to generate vectors for
each type of CPU present in the system. The generated sequences already
do some of the early guest-exit work (i.e. saving registers). To avoid
duplication the generated vectors branch to the original vector just
after the preamble. This size is hard coded.

Adding new instructions to the HYP vector causes strange side effects,
which are difficult to debug as the affected code is patched in at
runtime.

Add KVM_VECTOR_PREAMBLE to tell kvm_patch_vector_branch() how big
the preamble is. The valid_vect macro can then validate this at
build time.

Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:29 +01:00
Thomas Gleixner
caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00
Andrew Murray
630a16854d arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_data
The virt/arm core allocates a kvm_cpu_context_t percpu, at present this is
a typedef to kvm_cpu_context and is used to store host cpu context. The
kvm_cpu_context structure is also used elsewhere to hold vcpu context.
In order to use the percpu to hold additional future host information we
encapsulate kvm_cpu_context in a new structure and rename the typedef and
percpu to match.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24 15:35:24 +01:00
Marc Zyngier
58466766cd arm/arm64: KVM: Add ARM_EXCEPTION_IS_TRAP macro
32 and 64bit use different symbols to identify the traps.
32bit has a fine grained approach (prefetch abort, data abort and HVC),
while 64bit is pretty happy with just "trap".

This has been fine so far, except that we now need to decode some
of that in tracepoints that are common to both architectures.

Introduce ARM_EXCEPTION_IS_TRAP which abstracts the trap symbols
and make the tracepoint use it.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:53 +00:00
Christoffer Dall
71a7e47f39 KVM: arm/arm64: Fixup the kvm_exit tracepoint
The kvm_exit tracepoint strangely always reported exits as being IRQs.
This seems to be because either the __print_symbolic or the tracepoint
macros use a variable named idx.

Take this chance to update the fields in the tracepoint to reflect the
concepts in the arm64 architecture that we pass to the tracepoint and
move the exception type table to the same location and header files as
the exits code.

We also clear out the exception code to 0 for IRQ exits (which
translates to UNKNOWN in text) to make it slighyly less confusing to
parse the trace output.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:06 +00:00
Christoffer Dall
e4e11cc0f8 KVM: arm64: Safety check PSTATE when entering guest and handle IL
This commit adds a paranoid check when entering the guest to make sure
we don't attempt running guest code in an equally or more privilged mode
than the hypervisor.  We also catch other accidental programming of the
SPSR_EL2 which results in an illegal exception return and report this
safely back to the user.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-10-19 11:13:03 +01:00
Suzuki K Poulose
7665f3a849 kvm: arm64: Configure VTCR_EL2 per VM
Add support for setting the VTCR_EL2 per VM, rather than hard
coding a value at boot time per CPU. This would allow us to tune
the stage2 page table parameters per VM in the later changes.

We compute the VTCR fields based on the system wide sanitised
feature registers, except for the hardware management of Access
Flags (VTCR_EL2.HA). It is fine to run a system with a mix of
CPUs that may or may not update the page table Access Flags.
Since the bit is RES0 on CPUs that don't support it, the bit
should be ignored on them.

Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-10-01 13:50:29 +01:00
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