diff options
author | Sean Christopherson <seanjc@google.com> | 2023-01-25 02:49:00 +0300 |
---|---|---|
committer | Sean Christopherson <seanjc@google.com> | 2023-01-27 05:03:42 +0300 |
commit | 8911ce66697e04ce7e92753dbf5645f748e27e12 (patch) | |
tree | e34fece68393ccf1c987390adc3d9488c7dfe4f8 /arch/x86/kvm/pmu.h | |
parent | 2a3003e9507c0315e0642247230899485c488ff8 (diff) | |
download | linux-8911ce66697e04ce7e92753dbf5645f748e27e12.tar.xz |
KVM: x86/pmu: Cap kvm_pmu_cap.num_counters_gp at KVM's internal max
Limit kvm_pmu_cap.num_counters_gp during kvm_init_pmu_capability() based
on the vendor PMU capabilities so that consuming num_counters_gp naturally
does the right thing. This fixes a mostly theoretical bug where KVM could
over-report its PMU support in KVM_GET_SUPPORTED_CPUID for leaf 0xA, e.g.
if the number of counters reported by perf is greater than KVM's
hardcoded internal limit. Incorporating input from the AMD PMU also
avoids over-reporting MSRs to save when running on AMD.
Link: https://lore.kernel.org/r/20230124234905.3774678-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/pmu.h')
-rw-r--r-- | arch/x86/kvm/pmu.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h index 080a3bbbeda3..79988dafb15b 100644 --- a/arch/x86/kvm/pmu.h +++ b/arch/x86/kvm/pmu.h @@ -36,6 +36,7 @@ struct kvm_pmu_ops { void (*cleanup)(struct kvm_vcpu *vcpu); const u64 EVENTSEL_EVENT; + const int MAX_NR_GP_COUNTERS; }; void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops); @@ -157,7 +158,7 @@ static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc) extern struct x86_pmu_capability kvm_pmu_cap; -static inline void kvm_init_pmu_capability(void) +static inline void kvm_init_pmu_capability(const struct kvm_pmu_ops *pmu_ops) { bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL; @@ -176,6 +177,8 @@ static inline void kvm_init_pmu_capability(void) } kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2); + kvm_pmu_cap.num_counters_gp = min(kvm_pmu_cap.num_counters_gp, + pmu_ops->MAX_NR_GP_COUNTERS); kvm_pmu_cap.num_counters_fixed = min(kvm_pmu_cap.num_counters_fixed, KVM_PMC_MAX_FIXED); } |