On Fri, Jun 20, 2025 at 10:13:01PM +0000, Colton Lewis wrote:
Add a capability for FEAT_HPMN0, whether MDCR_EL2.HPMN can specify 0 counters reserved for the guest.
This required changing HPMN0 to an UnsignedEnum in tools/sysreg because otherwise not all the appropriate macros are generated to add it to arm64_cpu_capabilities_arm64_features.
Signed-off-by: Colton Lewis coltonlewis@google.com
arch/arm64/kernel/cpufeature.c | 8 ++++++++ arch/arm64/tools/cpucaps | 1 + arch/arm64/tools/sysreg | 6 +++--- 3 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index b34044e20128..278294fdc97d 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -548,6 +548,7 @@ static const struct arm64_ftr_bits ftr_id_mmfr0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
- ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_HPMN0_SHIFT, 4, 0), S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_DoubleLock_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_PMSVer_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_EL1_CTX_CMPs_SHIFT, 4, 0),
@@ -2896,6 +2897,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, ARM64_CPUID_FIELDS(ID_AA64MMFR0_EL1, FGT, FGT2) },
- {
.desc = "Allow MDCR_EL2.HPMN = 0",
This feedback still stands...
.desc = "HPMN0",
[*] https://lore.kernel.org/kvm/aD4ijUaSGm9b2g5H@linux.dev/
.type = ARM64_CPUCAP_SYSTEM_FEATURE,.capability = ARM64_HAS_HPMN0,.matches = has_cpuid_feature,ARM64_CPUID_FIELDS(ID_AA64DFR0_EL1, HPMN0, IMP)- },
#ifdef CONFIG_ARM64_SME { .desc = "Scalable Matrix Extension", diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 10effd4cff6b..5b196ba21629 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -39,6 +39,7 @@ HAS_GIC_CPUIF_SYSREGS HAS_GIC_PRIO_MASKING HAS_GIC_PRIO_RELAXED_SYNC HAS_HCR_NV1 +HAS_HPMN0 HAS_HCX HAS_LDAPR HAS_LPA2 diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg index 8a8cf6874298..d29742481754 100644 --- a/arch/arm64/tools/sysreg +++ b/arch/arm64/tools/sysreg @@ -1531,9 +1531,9 @@ EndEnum EndSysreg Sysreg ID_AA64DFR0_EL1 3 0 0 5 0 -Enum 63:60 HPMN0
- 0b0000 UNPREDICTABLE
- 0b0001 DEF
+UnsignedEnum 63:60 HPMN0
- 0b0000 NI
- 0b0001 IMP
EndEnum UnsignedEnum 59:56 ExtTrcBuff 0b0000 NI -- 2.50.0.714.g196bf9f422-goog