diff options
| -rw-r--r-- | arch/x86/kvm/vmx/pmu_intel.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 03bd188b5754..5a5dfae6055c 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -27,7 +27,6 @@ * "fast" reads, whereas the "type" is an explicit value. */ #define INTEL_RDPMC_FIXED INTEL_PMC_FIXED_RDPMC_BASE -#define INTEL_RDPMC_FAST BIT(31) #define MSR_PMC_FULL_WIDTH_BIT (MSR_IA32_PMC0 - MSR_IA32_PERFCTR0) @@ -72,10 +71,25 @@ static struct kvm_pmc *intel_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu, struct kvm_pmc *counters; unsigned int num_counters; - if (idx & INTEL_RDPMC_FAST) - *mask &= GENMASK_ULL(31, 0); + /* + * The encoding of ECX for RDPMC is different for architectural versus + * non-architecturals PMUs (PMUs with version '0'). For architectural + * PMUs, bits 31:16 specify the PMC type and bits 15:0 specify the PMC + * index. For non-architectural PMUs, bit 31 is a "fast" flag, and + * bits 30:0 specify the PMC index. + * + * Yell and reject attempts to read PMCs for a non-architectural PMU, + * as KVM doesn't support such PMUs. + */ + if (WARN_ON_ONCE(!pmu->version)) + return NULL; - idx &= ~(INTEL_RDPMC_FIXED | INTEL_RDPMC_FAST); + /* + * Fixed PMCs are supported on all architectural PMUs. Note, KVM only + * emulates fixed PMCs for PMU v2+, but the flag itself is still valid, + * i.e. let RDPMC fail due to accessing a non-existent counter. + */ + idx &= ~INTEL_RDPMC_FIXED; if (fixed) { counters = pmu->fixed_counters; num_counters = pmu->nr_arch_fixed_counters; |