From: Oliver Upton Date: Wed, 5 Mar 2025 20:26:35 +0000 (-0800) Subject: KVM: arm64: Move PMUVer filtering into KVM code X-Git-Tag: v6.15-rc1~195^2~2^2~3^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=56290316a443709957f958e4e40bc93e0213bcc3;p=thirdparty%2Fkernel%2Flinux.git KVM: arm64: Move PMUVer filtering into KVM code The supported guest PMU version on a particular platform is ultimately a KVM decision. Move PMUVer filtering into KVM code. Tested-by: Janne Grunau Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20250305202641.428114-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 0eff048848b84..c4326f1cb9176 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -525,29 +525,6 @@ cpuid_feature_extract_unsigned_field(u64 features, int field) return cpuid_feature_extract_unsigned_field_width(features, field, 4); } -/* - * Fields that identify the version of the Performance Monitors Extension do - * not follow the standard ID scheme. See ARM DDI 0487E.a page D13-2825, - * "Alternative ID scheme used for the Performance Monitors Extension version". - */ -static inline u64 __attribute_const__ -cpuid_feature_cap_perfmon_field(u64 features, int field, u64 cap) -{ - u64 val = cpuid_feature_extract_unsigned_field(features, field); - u64 mask = GENMASK_ULL(field + 3, field); - - /* Treat IMPLEMENTATION DEFINED functionality as unimplemented */ - if (val == ID_AA64DFR0_EL1_PMUVer_IMP_DEF) - val = 0; - - if (val > cap) { - features &= ~mask; - features |= (cap << field) & mask; - } - - return features; -} - static inline u64 arm64_ftr_mask(const struct arm64_ftr_bits *ftrp) { return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift); diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index fee3d0003d544..0a2023aabe184 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -1226,13 +1226,16 @@ int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) u8 kvm_arm_pmu_get_pmuver_limit(void) { - u64 tmp; + unsigned int pmuver; - tmp = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1); - tmp = cpuid_feature_cap_perfmon_field(tmp, - ID_AA64DFR0_EL1_PMUVer_SHIFT, - ID_AA64DFR0_EL1_PMUVer_V3P5); - return FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), tmp); + pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, + read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1)); + + /* Treat IMPLEMENTATION DEFINED functionality as unimplemented */ + if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF) + return 0; + + return min(pmuver, ID_AA64DFR0_EL1_PMUVer_V3P5); } /**