diff options
| author | Oliver Upton <oliver.upton@linux.dev> | 2025-02-24 16:53:57 -0800 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2025-02-26 01:31:52 -0800 |
| commit | 4cd48565b0e5df398e7253c0d2d8c0403d69e7bf (patch) | |
| tree | 3f13231de274a450d46e2d3661847aa6a8d6dfe1 /arch/arm64/include | |
| parent | 0ad2507d5d93f39619fc42372c347d6006b64319 (diff) | |
KVM: arm64: Set HCR_EL2.TID1 unconditionally
commit 90807748ca3a ("KVM: arm64: Hide SME system registers from
guests") added trap handling for SMIDR_EL1, treating it as UNDEFINED as
KVM does not support SME. This is right for the most part, however KVM
needs to set HCR_EL2.TID1 to _actually_ trap the register.
Unfortunately, this comes with some collateral damage as TID1 forces
REVIDR_EL1 and AIDR_EL1 to trap as well. KVM has long treated these
registers as "invariant" which is an awful term for the following:
- Userspace sees the boot CPU values on all vCPUs
- The guest sees the hardware values of the CPU on which a vCPU is
scheduled
Keep the plates spinning by adding trap handling for the affected
registers and repaint all of the "invariant" crud into terms of
identifying an implementation. Yes, at this point we only need to
set TID1 on SME hardware, but REVIDR_EL1 and AIDR_EL1 are about to
become mutable anyway.
Cc: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 90807748ca3a ("KVM: arm64: Hide SME system registers from guests")
[maz: handle traps from 32bit]
Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225005401.679536-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/kvm_arm.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 8d94a6c0ed5c..b01c01e55de5 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -92,12 +92,12 @@ * SWIO: Turn set/way invalidates into set/way clean+invalidate * PTW: Take a stage2 fault if a stage1 walk steps in device memory * TID3: Trap EL1 reads of group 3 ID registers - * TID2: Trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and CSSELR_EL1 + * TID1: Trap REVIDR_EL1, AIDR_EL1, and SMIDR_EL1 */ #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \ HCR_BSU_IS | HCR_FB | HCR_TACR | \ HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \ - HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3) + HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3 | HCR_TID1) #define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA) #define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC) #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) |