diff options
| author | Marc Zyngier <maz@kernel.org> | 2023-05-15 18:00:16 +0100 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-05-21 19:09:44 +0000 |
| commit | c876c3f182a5cc16711962efdd9bf56b9fb84317 (patch) | |
| tree | def0af915d57007414ae8617bb0324515951fa4d /arch/arm64/kernel/cpufeature.c | |
| parent | f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6 (diff) | |
KVM: arm64: Relax trapping of CTR_EL0 when FEAT_EVT is available
CTR_EL0 can often be used in userspace, and it would be nice if
KVM didn't have to emulate it unnecessarily.
While it isn't possible to trap the cache configuration registers
independently from CTR_EL0 in the base ARMv8.0 architecture, FEAT_EVT
allows these cache configuration registers (CCSIDR_EL1, CCSIDR2_EL1,
CLIDR_EL1 and CSSELR_EL1) to be trapped independently by setting
HCR_EL2.TID4.
Switch to using TID4 instead of TID2 in the cases where FEAT_EVT
is available *and* that KVM doesn't need to sanitise CTR_EL0 to
paper over mismatched cache configurations.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230515170016.965378-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 7d7128c65161..4a2ab3f366de 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2641,6 +2641,17 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .cpu_enable = cpu_enable_dit, ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, DIT, IMP) }, + { + .desc = "Enhanced Virtualization Traps", + .capability = ARM64_HAS_EVT, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .sys_reg = SYS_ID_AA64MMFR2_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64MMFR2_EL1_EVT_SHIFT, + .field_width = 4, + .min_field_value = ID_AA64MMFR2_EL1_EVT_IMP, + .matches = has_cpuid_feature, + }, {}, }; |