Commit Graph

68 Commits

Author SHA1 Message Date
Marc Zyngier
5c7cf1e44e KVM: arm64: selftests: Fix misleading comment about virtual timer encoding
The userspace-visible encoding for CNTV_CVAL_EL0 and CNTVCNT_EL0
have been swapped for as long as usersapce has had access to the
registers. This is documented in arch/arm64/include/uapi/asm/kvm.h.

Despite that, the get_reg_list test has unhelpful comments indicating
the wrong register for the encoding.

Replace this with definitions exposed in the include file, and
a comment explaining again the brokenness.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:43:12 +01:00
Marc Zyngier
4da5a9af78 KVM: arm64: selftests: Add an E2H=0-specific configuration to get_reg_list
Add yet another configuration, this time dealing E2H=0.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:42:41 +01:00
Marc Zyngier
6418330c84 KVM: arm64: selftests: Make dependencies on VHE-specific registers explicit
The hyp virtual timer registers only exist when VHE is present,
Similarly, VNCR_EL2 only exists when NV2 is present.

Make these dependencies explicit.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:42:41 +01:00
Oliver Upton
d5e6310a0d KVM: arm64: selftests: Actually enable IRQs in vgic_lpi_stress
vgic_lpi_stress rather hilariously leaves IRQs disabled for the duration
of the test. While the ITS translation of MSIs happens regardless of
this, for completeness the guest should actually handle the LPIs.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:28:27 +01:00
Zenghui Yu
2192d348c0 KVM: arm64: selftests: Allocate vcpus with correct size
vcpus array contains pointers to struct kvm_vcpu {}. It is way overkill
to allocate the array with (nr_cpus * sizeof(struct kvm_vcpu)). Fix the
allocation by using the correct size.

Signed-off-by: Zenghui Yu <zenghui.yu@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:27:55 +01:00
Zenghui Yu
9a7f87eb58 KVM: arm64: selftests: Sync ID_AA64PFR1, MPIDR, CLIDR in guest
We forgot to sync several registers (ID_AA64PFR1, MPIDR, CLIDR) in guest to
make sure that the guest had seen the written value.

Add them to the list.

Signed-off-by: Zenghui Yu <zenghui.yu@linux.dev>
Reviewed-By: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:17:03 +01:00
Sean Christopherson
cb49b7b862 KVM: arm64: selftests: Track width of timer counter as "int", not "uint64_t"
Store the width of arm64's timer counter as an "int", not a "uint64_t".
ilog2() returns an "int", and more importantly using what is an "unsigned
long" under the hood makes clang unhappy due to a type mismatch when
clamping the width to a sane value.

  arm64/arch_timer_edge_cases.c:1032:10: error: comparison of distinct pointer types
     ('typeof (width) *' (aka 'unsigned long *') and 'typeof (56) *' (aka 'int *'))
     [-Werror,-Wcompare-distinct-pointer-types]
   1032 |         width = clamp(width, 56, 64);
        |                 ^~~~~~~~~~~~~~~~~~~~
  tools/include/linux/kernel.h:47:45: note: expanded from macro 'clamp'
     47 | #define clamp(val, lo, hi)      min((typeof(val))max(val, lo), hi)
        |                                                  ^~~~~~~~~~~~
  tools/include/linux/kernel.h:33:17: note: expanded from macro 'max'
     33 |         (void) (&_max1 == &_max2);              \
        |                 ~~~~~~ ^  ~~~~~~
  tools/include/linux/kernel.h:39:9: note: expanded from macro 'min'
     39 |         typeof(x) _min1 = (x);                  \
        |                ^

Fixes: fad4cf9448 ("KVM: arm64: selftests: Determine effective counter width in arch_timer_edge_cases")
Cc: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:17:03 +01:00
Oliver Upton
890c608b4d KVM: arm64: selftests: Test effective value of HCR_EL2.AMO
A defect against the architecture now allows an implementation to treat
AMO as 1 when HCR_EL2.{E2H, TGE} = {1, 0}. KVM now takes advantage of
this interpretation to address a quality of emulation issue w.r.t.
SError injection.

Add a corresponding test case and expect a pending SError to be taken.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:17:03 +01:00
Marc Zyngier
10fd028530 Merge branch kvm-arm64/selftests-6.18 into kvmarm-master/next
* kvm-arm64/selftests-6.18:
  : .
  : KVM/arm64 selftest updates for 6.18:
  :
  : - Large update to run EL1 selftests at EL2 when possible
  :   (20250917212044.294760-1-oliver.upton@linux.dev)
  :
  : - Work around lack of ID_AA64MMFR4_EL1 trapping on CPUs
  :   without FEAT_FGT
  :   (20250923173006.467455-1-oliver.upton@linux.dev)
  :
  : - Additional fixes and cleanups
  :   (20250920-kvm-arm64-id-aa64isar3-el1-v1-0-1764c1c1c96d@kernel.org)
  : .
  KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs
  KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs
  KVM: arm64: selftests: Cope with arch silliness in EL2 selftest
  KVM: arm64: selftests: Add basic test for running in VHE EL2
  KVM: arm64: selftests: Enable EL2 by default
  KVM: arm64: selftests: Initialize HCR_EL2
  KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters
  KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2
  KVM: arm64: selftests: Select SMCCC conduit based on current EL
  KVM: arm64: selftests: Provide helper for getting default vCPU target
  KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts
  KVM: arm64: selftests: Create a VGICv3 for 'default' VMs
  KVM: arm64: selftests: Add unsanitised helpers for VGICv3 creation
  KVM: arm64: selftests: Add helper to check for VGICv3 support
  KVM: arm64: selftests: Initialize VGICv3 only once
  KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:35:50 +01:00
Mark Brown
b02a2c060b KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs
We have a couple of writable bitfields in ID_AA64ISAR3_EL1 but the
set_id_regs selftest does not cover this register at all, add coverage.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:24:57 +01:00
Mark Brown
5a070fc376 KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs
Currently we list the main set of registers with bits we test three
times, once in the test_regs array which is used at runtime, once in the
guest code and once in a list of ARRAY_SIZE() operations we use to tell
kselftest how many tests we plan to execute. This is needlessly fiddly,
when adding new registers as the test_cnt calculation is formatted with
two registers per line. Instead count the number of bitfields in the
register arrays at runtime.

The existing code subtracts ARRAY_SIZE(test_regs) from the number of
tests to account for the terminating FTR_REG_END entries in the per
register arrays, the new code accounts for this when enumerating.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:24:57 +01:00
Oliver Upton
75b2fdc1a8 KVM: arm64: selftests: Cope with arch silliness in EL2 selftest
Implementations without FEAT_FGT aren't required to trap the entire ID
register space when HCR_EL2.TID3 is set. This is a terrible idea, as the
hypervisor may need to advertise the absence of a feature to the VM
using a negative value in a signed field, FEAT_E2H0 being a great
example of this.

Cope with uncooperative implementations in the EL2 selftest by accepting
a zero value when FEAT_FGT is absent and otherwise only tolerating the
expected nonzero value.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:24:02 +01:00
Oliver Upton
f677b0efa9 KVM: arm64: selftests: Add basic test for running in VHE EL2
Add an embarrassingly simple selftest for sanity checking KVM's VHE EL2
and test that the ID register bits are consistent with HCR_EL2.E2H being
RES1.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
2de21fb623 KVM: arm64: selftests: Enable EL2 by default
Take advantage of VHE to implicitly promote KVM selftests to run at EL2
with only slight modification. Update the smccc_filter test to account
for this now that the EL2-ness of a VM is visible to tests.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
7ae44d1cda KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters
Configuring the number of implemented counters via PMCR_EL0.N was a bad
idea in retrospect as it interacts poorly with nested. Migrate the
selftest to use the vCPU attribute instead of the KVM_SET_ONE_REG
mechanism.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
0910778e49 KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2
Arch timer registers are redirected to their hypervisor counterparts
when running in VHE EL2. This is great, except for the fact that the
hypervisor timers use different PPIs. Use the correct INTIDs when that
is the case.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
d72543ac72 KVM: arm64: selftests: Select SMCCC conduit based on current EL
HVCs are taken within the VM when EL2 is in use. Ensure tests use the
SMC instruction when running at EL2 to interact with the host.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
a1b91ac238 KVM: arm64: selftests: Provide helper for getting default vCPU target
The default vCPU target in KVM selftests is pretty boring in that it
doesn't enable any vCPU features. Expose a helper for getting the
default target to prepare for cramming in more features. Call
KVM_ARM_PREFERRED_TARGET directly from get-reg-list as it needs
fine-grained control over feature flags.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Itaru Kitayama <itaru.kitayama@fujitsu.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
1c9604ba23 KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts
FEAT_VHE has the somewhat nice property of implicitly redirecting EL1
register aliases to their corresponding EL2 representations when E2H=1.
Unfortunately, there's no such abstraction for userspace and EL2
registers are always accessed by their canonical encoding.

Introduce a helper that applies EL2 redirections to sysregs and use
aggressive inlining to catch misuse at compile time. Go a little past
the architectural definition for ease of use for test authors (e.g. the
stack pointer).

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
8911c7dbc6 KVM: arm64: selftests: Create a VGICv3 for 'default' VMs
Start creating a VGICv3 by default unless explicitly opted-out by the
test. While having an interrupt controller is nice, the real benefit
here is clearing a hurdle for EL2 VMs which mandate the presence of a
VGIC.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
b712afa7a1 KVM: arm64: selftests: Add helper to check for VGICv3 support
Introduce a proper predicate for probing VGICv3 by performing a 'test'
creation of the device on a dummy VM.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:32 +01:00
Oliver Upton
7326348209 KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code
In order to compel the default usage of EL2 in selftests, move
kvm_arch_vm_post_create() to library code and expose an opt-in for using
MTE by default.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-24 19:23:31 +01:00
Marc Zyngier
46bd74ef07 Merge branch kvm-arm64/el2-feature-control into kvmarm-master/next
* kvm-arm64/el2-feature-control: (23 commits)
  : .
  : General rework of EL2 features that can be disabled to satisfy
  : the requirement of migration between heterogeneous hosts:
  :
  : - Handle effective RES0 behaviour of undefined registers, making sure
  :   that disabling a feature affects full registeres, and not just
  :   individual control bits. (20250918151402.1665315-1-maz@kernel.org)
  :
  : - Allow ID_AA64MMFR1_EL1.{TWED,HCX} to be disabled from userspace.
  :   (20250911114621.3724469-1-yangjinqian1@huawei.com)
  :
  : - Turn the NV feature management into a deny-list, and expose
  :   missing features to EL2 guests.
  :   (20250912212258.407350-1-oliver.upton@linux.dev)
  : .
  KVM: arm64: nv: Expose up to FEAT_Debugv8p8 to NV-enabled VMs
  KVM: arm64: nv: Advertise FEAT_TIDCP1 to NV-enabled VMs
  KVM: arm64: nv: Advertise FEAT_SpecSEI to NV-enabled VMs
  KVM: arm64: nv: Expose FEAT_TWED to NV-enabled VMs
  KVM: arm64: nv: Exclude guest's TWED configuration when TWE isn't set
  KVM: arm64: nv: Expose FEAT_AFP to NV-enabled VMs
  KVM: arm64: nv: Expose FEAT_ECBHB to NV-enabled VMs
  KVM: arm64: nv: Expose FEAT_RASv1p1 via RAS_frac
  KVM: arm64: nv: Expose FEAT_DF2 to NV-enabled VMs
  KVM: arm64: nv: Don't erroneously claim FEAT_DoubleLock for NV VMs
  KVM: arm64: nv: Convert masks to denylists in limit_nv_id_reg()
  KVM: arm64: selftests: Test writes to ID_AA64MMFR1_EL1.{HCX, TWED}
  KVM: arm64: Make ID_AA64MMFR1_EL1.{HCX, TWED} writable from userspace
  KVM: arm64: Convert MDCR_EL2 RES0 handling to compute_reg_res0_bits()
  KVM: arm64: Convert SCTLR_EL1 RES0 handling to compute_reg_res0_bits()
  KVM: arm64: Enforce absence of FEAT_TCR2 on TCR2_EL2
  KVM: arm64: Enforce absence of FEAT_SCTLR2 on SCTLR2_EL{1,2}
  KVM: arm64: Convert HCR_EL2 RES0 handling to compute_reg_res0_bits()
  KVM: arm64: Enforce absence of FEAT_HCX on HCRX_EL2
  KVM: arm64: Enforce absence of FEAT_FGT2 on FGT2 registers
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 12:26:18 +01:00
Marc Zyngier
00a37271c8 KVM: arm64: selftest: Expand external_aborts test to look for TTW levels
Add a basic test corrupting a level-2 table entry to check that
the resulting abort is a SEA on a PTW at level-3.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:14 +01:00
Jinqian Yang
be8c9192ea KVM: arm64: selftests: Test writes to ID_AA64MMFR1_EL1.{HCX, TWED}
Assert that the EL2 features {HCX, TWED} of ID_AA64MMFR1_EL1 are writable
from userspace. They are only allowed to be downgraded in userspace.

Signed-off-by: Jinqian Yang <yangjinqian1@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-19 13:55:57 +01:00
Paolo Bonzini
42a0305ab1 Merge tag 'kvmarm-fixes-6.17-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 changes for 6.17, take #2

 - Correctly handle 'invariant' system registers for protected VMs

 - Improved handling of VNCR data aborts, including external aborts

 - Fixes for handling of FEAT_RAS for NV guests, providing a sane
   fault context during SEA injection and preventing the use of
   RASv1p1 fault injection hardware

 - Ensure that page table destruction when a VM is destroyed gives an
   opportunity to reschedule

 - Large fix to KVM's infrastructure for managing guest context loaded
   on the CPU, addressing issues where the output of AT emulation
   doesn't get reflected to the guest

 - Fix AT S12 emulation to actually perform stage-2 translation when
   necessary

 - Avoid attempting vLPI irqbypass when GICv4 has been explicitly
   disabled for a VM

 - Minor KVM + selftest fixes
2025-08-29 12:57:31 -04:00
Mark Brown
01860bcc53 KVM: arm64: selftests: Sync ID_AA64MMFR3_EL1 in set_id_regs
When we added coverage for ID_AA64MMFR3_EL1 we didn't add it to the list
of registers we read in the guest, do so.

Fixes: 0b593ef12a ("KVM: arm64: selftests: Catch up set_id_regs with the kernel")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250818-kvm-arm64-selftests-mmfr3-idreg-v1-1-2f85114d0163@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-08-21 16:36:30 -07:00
Marc Zyngier
0843e0ced3 KVM: arm64: Get rid of ARM64_FEATURE_MASK()
The ARM64_FEATURE_MASK() macro was a hack introduce whilst the
automatic generation of sysreg encoding was introduced, and was
too unreliable to be entirely trusted.

We are in a better place now, and we could really do without this
macro. Get rid of it altogether.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250817202158.395078-7-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-08-21 16:31:56 -07:00
Marc Zyngier
85acc29f90 KVM: arm64: selftest: Add standalone test checking for KVM's own UUID
Tinkering with UUIDs is a perilious task, and the KVM UUID gets
broken at times. In order to spot this early enough, add a selftest
that will shout if the expected value isn't found.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Link: https://lore.kernel.org/r/20250721130558.50823-1-jackabt.amazon@gmail.com
Link: https://lore.kernel.org/r/20250806171341.1521210-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-08-08 01:30:16 -07:00
Linus Torvalds
63eb28bb14 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Host driver for GICv5, the next generation interrupt controller for
     arm64, including support for interrupt routing, MSIs, interrupt
     translation and wired interrupts

   - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
     GICv5 hardware, leveraging the legacy VGIC interface

   - Userspace control of the 'nASSGIcap' GICv3 feature, allowing
     userspace to disable support for SGIs w/o an active state on
     hardware that previously advertised it unconditionally

   - Map supporting endpoints with cacheable memory attributes on
     systems with FEAT_S2FWB and DIC where KVM no longer needs to
     perform cache maintenance on the address range

   - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the
     guest hypervisor to inject external aborts into an L2 VM and take
     traps of masked external aborts to the hypervisor

   - Convert more system register sanitization to the config-driven
     implementation

   - Fixes to the visibility of EL2 registers, namely making VGICv3
     system registers accessible through the VGIC device instead of the
     ONE_REG vCPU ioctls

   - Various cleanups and minor fixes

  LoongArch:

   - Add stat information for in-kernel irqchip

   - Add tracepoints for CPUCFG and CSR emulation exits

   - Enhance in-kernel irqchip emulation

   - Various cleanups

  RISC-V:

   - Enable ring-based dirty memory tracking

   - Improve perf kvm stat to report interrupt events

   - Delegate illegal instruction trap to VS-mode

   - MMU improvements related to upcoming nested virtualization

  s390x

   - Fixes

  x86:

   - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O
     APIC, PIC, and PIT emulation at compile time

   - Share device posted IRQ code between SVM and VMX and harden it
     against bugs and runtime errors

   - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups
     O(1) instead of O(n)

   - For MMIO stale data mitigation, track whether or not a vCPU has
     access to (host) MMIO based on whether the page tables have MMIO
     pfns mapped; using VFIO is prone to false negatives

   - Rework the MSR interception code so that the SVM and VMX APIs are
     more or less identical

   - Recalculate all MSR intercepts from scratch on MSR filter changes,
     instead of maintaining shadow bitmaps

   - Advertise support for LKGS (Load Kernel GS base), a new instruction
     that's loosely related to FRED, but is supported and enumerated
     independently

   - Fix a user-triggerable WARN that syzkaller found by setting the
     vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting
     the vCPU into VMX Root Mode (post-VMXON). Trying to detect every
     possible path leading to architecturally forbidden states is hard
     and even risks breaking userspace (if it goes from valid to valid
     state but passes through invalid states), so just wait until
     KVM_RUN to detect that the vCPU state isn't allowed

   - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling
     interception of APERF/MPERF reads, so that a "properly" configured
     VM can access APERF/MPERF. This has many caveats (APERF/MPERF
     cannot be zeroed on vCPU creation or saved/restored on suspend and
     resume, or preserved over thread migration let alone VM migration)
     but can be useful whenever you're interested in letting Linux
     guests see the effective physical CPU frequency in /proc/cpuinfo

   - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been
     created, as there's no known use case for changing the default
     frequency for other VM types and it goes counter to the very reason
     why the ioctl was added to the vm file descriptor. And also, there
     would be no way to make it work for confidential VMs with a
     "secure" TSC, so kill two birds with one stone

   - Dynamically allocation the shadow MMU's hashed page list, and defer
     allocating the hashed list until it's actually needed (the TDP MMU
     doesn't use the list)

   - Extract many of KVM's helpers for accessing architectural local
     APIC state to common x86 so that they can be shared by guest-side
     code for Secure AVIC

   - Various cleanups and fixes

  x86 (Intel):

   - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest.
     Failure to honor FREEZE_IN_SMM can leak host state into guests

   - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to
     prevent L1 from running L2 with features that KVM doesn't support,
     e.g. BTF

  x86 (AMD):

   - WARN and reject loading kvm-amd.ko instead of panicking the kernel
     if the nested SVM MSRPM offsets tracker can't handle an MSR (which
     is pretty much a static condition and therefore should never
     happen, but still)

   - Fix a variety of flaws and bugs in the AVIC device posted IRQ code

   - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware
     supports) instead of rejecting vCPU creation

   - Extend enable_ipiv module param support to SVM, by simply leaving
     IsRunning clear in the vCPU's physical ID table entry

   - Disable IPI virtualization, via enable_ipiv, if the CPU is affected
     by erratum #1235, to allow (safely) enabling AVIC on such CPUs

   - Request GA Log interrupts if and only if the target vCPU is
     blocking, i.e. only if KVM needs a notification in order to wake
     the vCPU

   - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to
     the vCPU's CPUID model

   - Accept any SNP policy that is accepted by the firmware with respect
     to SMT and single-socket restrictions. An incompatible policy
     doesn't put the kernel at risk in any way, so there's no reason for
     KVM to care

   - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and
     use WBNOINVD instead of WBINVD when possible for SEV cache
     maintenance

   - When reclaiming memory from an SEV guest, only do cache flushes on
     CPUs that have ever run a vCPU for the guest, i.e. don't flush the
     caches for CPUs that can't possibly have cache lines with dirty,
     encrypted data

  Generic:

   - Rework irqbypass to track/match producers and consumers via an
     xarray instead of a linked list. Using a linked list leads to
     O(n^2) insertion times, which is hugely problematic for use cases
     that create large numbers of VMs. Such use cases typically don't
     actually use irqbypass, but eliminating the pointless registration
     is a future problem to solve as it likely requires new uAPI

   - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a
     "void *", to avoid making a simple concept unnecessarily difficult
     to understand

   - Decouple device posted IRQs from VFIO device assignment, as binding
     a VM to a VFIO group is not a requirement for enabling device
     posted IRQs

   - Clean up and document/comment the irqfd assignment code

   - Disallow binding multiple irqfds to an eventfd with a priority
     waiter, i.e. ensure an eventfd is bound to at most one irqfd
     through the entire host, and add a selftest to verify eventfd:irqfd
     bindings are globally unique

   - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues
     related to private <=> shared memory conversions

   - Drop guest_memfd's .getattr() implementation as the VFS layer will
     call generic_fillattr() if inode_operations.getattr is NULL

   - Fix issues with dirty ring harvesting where KVM doesn't bound the
     processing of entries in any way, which allows userspace to keep
     KVM in a tight loop indefinitely

   - Kill off kvm_arch_{start,end}_assignment() and x86's associated
     tracking, now that KVM no longer uses assigned_device_count as a
     heuristic for either irqbypass usage or MDS mitigation

  Selftests:

   - Fix a comment typo

   - Verify KVM is loaded when getting any KVM module param so that
     attempting to run a selftest without kvm.ko loaded results in a
     SKIP message about KVM not being loaded/enabled (versus some random
     parameter not existing)

   - Skip tests that hit EACCES when attempting to access a file, and
     print a "Root required?" help message. In most cases, the test just
     needs to be run with elevated permissions"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits)
  Documentation: KVM: Use unordered list for pre-init VGIC registers
  RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map()
  RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs
  RISC-V: perf/kvm: Add reporting of interrupt events
  RISC-V: KVM: Enable ring-based dirty memory tracking
  RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap
  RISC-V: KVM: Delegate illegal instruction fault to VS mode
  RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs
  RISC-V: KVM: Factor-out g-stage page table management
  RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence
  RISC-V: KVM: Introduce struct kvm_gstage_mapping
  RISC-V: KVM: Factor-out MMU related declarations into separate headers
  RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect()
  RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range()
  RISC-V: KVM: Don't flush TLB when PTE is unchanged
  RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH
  RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize()
  RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init()
  RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value
  KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list
  ...
2025-07-30 17:14:01 -07:00
Linus Torvalds
6fb44438a5 Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
 "A quick summary: perf support for Branch Record Buffer Extensions
  (BRBE), typical PMU hardware updates, small additions to MTE for
  store-only tag checking and exposing non-address bits to signal
  handlers, HAVE_LIVEPATCH enabled on arm64, VMAP_STACK forced on.

  There is also a TLBI optimisation on hardware that does not require
  break-before-make when changing the user PTEs between contiguous and
  non-contiguous.

  More details:

  Perf and PMU updates:

   - Add support for new (v3) Hisilicon SLLC and DDRC PMUs

   - Add support for Arm-NI PMU integrations that share interrupts
     between clock domains within a given instance

   - Allow SPE to be configured with a lower sample period than the
     minimum recommendation advertised by PMSIDR_EL1.Interval

   - Add suppport for Arm's "Branch Record Buffer Extension" (BRBE)

   - Adjust the perf watchdog period according to cpu frequency changes

   - Minor driver fixes and cleanups

  Hardware features:

   - Support for MTE store-only checking (FEAT_MTE_STORE_ONLY)

   - Support for reporting the non-address bits during a synchronous MTE
     tag check fault (FEAT_MTE_TAGGED_FAR)

   - Optimise the TLBI when folding/unfolding contiguous PTEs on
     hardware with FEAT_BBM (break-before-make) level 2 and no TLB
     conflict aborts

  Software features:

   - Enable HAVE_LIVEPATCH after implementing arch_stack_walk_reliable()
     and using the text-poke API for late module relocations

   - Force VMAP_STACK always on and change arm64_efi_rt_init() to use
     arch_alloc_vmap_stack() in order to avoid KASAN false positives

  ACPI:

   - Improve SPCR handling and messaging on systems lacking an SPCR
     table

  Debug:

   - Simplify the debug exception entry path

   - Drop redundant DBG_MDSCR_* macros

  Kselftests:

   - Cleanups and improvements for SME, SVE and FPSIMD tests

  Miscellaneous:

   - Optimise loop to reduce redundant operations in contpte_ptep_get()

   - Remove ISB when resetting POR_EL0 during signal handling

   - Mark the kernel as tainted on SEA and SError panic

   - Remove redundant gcs_free() call"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits)
  arm64/gcs: task_gcs_el0_enable() should use passed task
  arm64: Kconfig: Keep selects somewhat alphabetically ordered
  arm64: signal: Remove ISB when resetting POR_EL0
  kselftest/arm64: Handle attempts to disable SM on SME only systems
  kselftest/arm64: Fix SVE write data generation for SME only systems
  kselftest/arm64: Test SME on SME only systems in fp-ptrace
  kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace
  kselftest/arm64: Allow sve-ptrace to run on SME only systems
  arm64/mm: Drop redundant addr increment in set_huge_pte_at()
  kselftest/arm4: Provide local defines for AT_HWCAP3
  arm64: Mark kernel as tainted on SAE and SError panic
  arm64/gcs: Don't call gcs_free() when releasing task_struct
  drivers/perf: hisi: Support PMUs with no interrupt
  drivers/perf: hisi: Relax the event number check of v2 PMUs
  drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver
  drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information
  drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver
  drivers/perf: hisi: Simplify the probe process for each DDRC version
  perf/arm-ni: Support sharing IRQs within an NI instance
  perf/arm-ni: Consolidate CPU affinity handling
  ...
2025-07-29 20:21:54 -07:00
Paolo Bonzini
314b40b3b6 Merge tag 'kvmarm-6.17' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 changes for 6.17, round #1

 - Host driver for GICv5, the next generation interrupt controller for
   arm64, including support for interrupt routing, MSIs, interrupt
   translation and wired interrupts.

 - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
   GICv5 hardware, leveraging the legacy VGIC interface.

 - Userspace control of the 'nASSGIcap' GICv3 feature, allowing
   userspace to disable support for SGIs w/o an active state on hardware
   that previously advertised it unconditionally.

 - Map supporting endpoints with cacheable memory attributes on systems
   with FEAT_S2FWB and DIC where KVM no longer needs to perform cache
   maintenance on the address range.

 - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest
   hypervisor to inject external aborts into an L2 VM and take traps of
   masked external aborts to the hypervisor.

 - Convert more system register sanitization to the config-driven
   implementation.

 - Fixes to the visibility of EL2 registers, namely making VGICv3 system
   registers accessible through the VGIC device instead of the ONE_REG
   vCPU ioctls.

 - Various cleanups and minor fixes.
2025-07-29 12:27:40 -04:00
Paolo Bonzini
1a14928e2e Merge tag 'kvm-x86-misc-6.17' of https://github.com/kvm-x86/linux into HEAD
KVM x86 misc changes for 6.17

 - Prevert the host's DEBUGCTL.FREEZE_IN_SMM (Intel only) when running the
   guest.  Failure to honor FREEZE_IN_SMM can bleed host state into the guest.

 - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter (Intel only) to
   prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF.

 - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the
   vCPU's CPUID model.

 - Rework the MSR interception code so that the SVM and VMX APIs are more or
   less identical.

 - Recalculate all MSR intercepts from the "source" on MSR filter changes, and
   drop the dedicated "shadow" bitmaps (and their awful "max" size defines).

 - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the
   nested SVM MSRPM offsets tracker can't handle an MSR.

 - Advertise support for LKGS (Load Kernel GS base), a new instruction that's
   loosely related to FRED, but is supported and enumerated independently.

 - Fix a user-triggerable WARN that syzkaller found by stuffing INIT_RECEIVED,
   a.k.a. WFS, and then putting the vCPU into VMX Root Mode (post-VMXON).  Use
   the same approach KVM uses for dealing with "impossible" emulation when
   running a !URG guest, and simply wait until KVM_RUN to detect that the vCPU
   has architecturally impossible state.

 - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of
   APERF/MPERF reads, so that a "properly" configured VM can "virtualize"
   APERF/MPERF (with many caveats).

 - Reject KVM_SET_TSC_KHZ if vCPUs have been created, as changing the "default"
   frequency is unsupported for VMs with a "secure" TSC, and there's no known
   use case for changing the default frequency for other VM types.
2025-07-29 08:36:43 -04:00
Oliver Upton
18ec25dd0e KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list
VDISR_EL2 and VSESR_EL2 are now visible to userspace for nested VMs. Add
them to get-reg-list.

Link: https://lore.kernel.org/r/20250728152603.2823699-1-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-28 08:28:05 -07:00
Oliver Upton
0d46e324c0 Merge branch 'kvm-arm64/vgic-v4-ctl' into kvmarm/next
* kvm-arm64/vgic-v4-ctl:
  : Userspace control of nASSGIcap, courtesy of Raghavendra Rao Ananta
  :
  : Allow userspace to decide if support for SGIs without an active state is
  : advertised to the guest, allowing VMs from GICv3-only hardware to be
  : migrated to to GICv4.1 capable machines.
  Documentation: KVM: arm64: Describe VGICv3 registers writable pre-init
  KVM: arm64: selftests: Add test for nASSGIcap attribute
  KVM: arm64: vgic-v3: Allow userspace to write GICD_TYPER2.nASSGIcap
  KVM: arm64: vgic-v3: Allow access to GICD_IIDR prior to initialization
  KVM: arm64: vgic-v3: Consolidate MAINT_IRQ handling
  KVM: arm64: Disambiguate support for vSGIs v. vLPIs

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-28 08:11:38 -07:00
Oliver Upton
a7f49a9bf4 Merge branch 'kvm-arm64/el2-reg-visibility' into kvmarm/next
* kvm-arm64/el2-reg-visibility:
  : Fixes to EL2 register visibility, courtesy of Marc Zyngier
  :
  :  - Expose EL2 VGICv3 registers via the VGIC attributes accessor, not the
  :    KVM_{GET,SET}_ONE_REG ioctls
  :
  :  - Condition visibility of FGT registers on the presence of FEAT_FGT in
  :    the VM
  KVM: arm64: selftest: vgic-v3: Add basic GICv3 sysreg userspace access test
  KVM: arm64: Enforce the sorting of the GICv3 system register table
  KVM: arm64: Clarify the check for reset callback in check_sysreg_table()
  KVM: arm64: vgic-v3: Fix ordering of ICH_HCR_EL2
  KVM: arm64: Document registers exposed via KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS
  KVM: arm64: selftests: get-reg-list: Add base EL2 registers
  KVM: arm64: selftests: get-reg-list: Simplify feature dependency
  KVM: arm64: Advertise FGT2 registers to userspace
  KVM: arm64: Condition FGT registers on feature availability
  KVM: arm64: Expose GICv3 EL2 registers via KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS
  KVM: arm64: Let GICv3 save/restore honor visibility attribute
  KVM: arm64: Define helper for ICH_VTR_EL2
  KVM: arm64: Define constant value for ICC_SRE_EL2
  KVM: arm64: Don't advertise ICH_*_EL2 registers through GET_ONE_REG
  KVM: arm64: Make RVBAR_EL2 accesses UNDEF

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-28 08:06:38 -07:00
Raghavendra Rao Ananta
15b5964a41 KVM: arm64: selftests: Add test for nASSGIcap attribute
Extend vgic_init to test the nASSGIcap attribute, asserting that it is
configurable (within reason) prior to initializing the VGIC.
Additionally, check that userspace cannot set the attribute after the
VGIC has been initialized.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250724062805.2658919-6-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-26 08:45:52 -07:00
Marc Zyngier
3435bd79ec KVM: arm64: selftest: vgic-v3: Add basic GICv3 sysreg userspace access test
We have a lot of more or less useful vgic tests, but none of them
tracks the availability of GICv3 system registers, which is a bit
annoying.

Add one such test, which covers both EL1 and EL2 registers.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Itaru Kitayama <itaru.kitayama@fujitsu.com>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Link: https://lore.kernel.org/r/20250718111154.104029-5-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-26 08:36:58 -07:00
Marc Zyngier
3a90b6f279 KVM: arm64: selftests: get-reg-list: Add base EL2 registers
Add the EL2 registers and the eventual dependencies, effectively
doubling the number of test vectors. Oh well.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250714122634.3334816-11-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15 20:24:29 -07:00
Marc Zyngier
9a40718079 KVM: arm64: selftests: get-reg-list: Simplify feature dependency
Describing the dependencies between registers and features is on
the masochistic side of things, with hard-coded values that would
be better taken from the existing description.

Add a couple of helpers to that effect, and repaint the dependency
array. More could be done to improve this test, but my interest is
wearing  thin...

Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Itaru Kitayama <itaru.kitayama@fujitsu.com>
Link: https://lore.kernel.org/r/20250714122634.3334816-10-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15 20:24:29 -07:00
Oliver Upton
f9e4e0a663 KVM: arm64: selftests: Test ESR propagation for vSError injection
Ensure that vSErrors taken in the guest have an appropriate ESR_ELx
value for the expected exception. Additionally, switch the EASE test to
install the SEA handler at the SError offset, as the ESR is still
expected to match an SEA in that case.

Link: https://lore.kernel.org/r/20250708230632.1954240-3-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-09 09:55:05 -07:00
Sean Christopherson
95826e1ed3 KVM: selftests: Convert arch_timer tests to common helpers to pin task
Convert the arch timer tests to use __pin_task_to_cpu() and
pin_self_to_cpu().

No functional change intended.

Link: https://lore.kernel.org/r/20250626001225.744268-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-07-09 09:33:42 -07:00
Oliver Upton
0b593ef12a KVM: arm64: selftests: Catch up set_id_regs with the kernel
Add test coverage for ID_AA64MMFR3_EL1 and the recently added
FEAT_DoubleFault2.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-28-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08 11:36:36 -07:00
Oliver Upton
55ea75f5b2 KVM: arm64: selftests: Add SCTLR2_EL1 to get-reg-list
Handle SCTLR2_EL1 specially as it is only visible to userspace when
FEAT_SCTLR2 is implemented for the VM.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-27-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08 11:36:36 -07:00
Oliver Upton
a90aac5532 KVM: arm64: selftests: Test SEAs are taken to SError vector when EASE=1
Ensure KVM routes SEAs to the correct vector depending on
SCTLR2_EL1.EASE.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-26-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08 11:36:36 -07:00
Oliver Upton
2858ea3083 KVM: arm64: selftests: Add basic SError injection test
Add tests for SError injection considering KVM is more directly involved
in delivery:

 - Pending SErrors are taken at the first CSE after SErrors are unmasked

 - Pending SErrors aren't taken and remain pending if SErrors are masked

 - Unmasked SErrors are taken immediately when injected (implementation
   detail)

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-25-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08 11:36:36 -07:00
Anshuman Khandual
30ff3c981e KVM: selftests: Change MDSCR_EL1 register holding variables as uint64_t
Change MDSCR_EL1 register holding local variables as uint64_t that reflects
its true register width as well.

Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: kvm@vger.kernel.org
Cc: kvmarm@lists.linux.dev
Cc: linux-kernel@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250613023646.1215700-3-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-03 20:00:37 +01:00
Sean Christopherson
74e5e3fb0d KVM: selftests: Add utilities to create eventfds and do KVM_IRQFD
Add helpers to create eventfds and to (de)assign eventfds via KVM_IRQFD.

Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250522235223.3178519-13-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-06-23 09:51:01 -07:00
Zenghui Yu
56a1498450 KVM: arm64: selftests: Close the GIC FD in arch_timer_edge_cases
Close the GIC FD to free the reference it holds to the VM so that we can
correctly clean up the VM. This also gets rid of the

	"KVM: debugfs: duplicate directory 395722-4"

warning when running arch_timer_edge_cases.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Link: https://lore.kernel.org/r/20250608095402.1131-1-yuzenghui@huawei.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-06-19 09:58:21 +01:00
Paolo Bonzini
ce360c2bfd Merge tag 'kvmarm-fixes-6.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 6.16, take #2

- Rework of system register accessors for system registers that are
  directly writen to memory, so that sanitisation of the in-memory
  value happens at the correct time (after the read, or before the
  write). For convenience, RMW-style accessors are also provided.

- Multiple fixes for the so-called "arch-timer-edge-cases' selftest,
  which was always broken.
2025-06-11 14:25:22 -04:00