aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLike Xu <[email protected]>2023-06-02 18:10:55 -0700
committerSean Christopherson <[email protected]>2023-06-06 17:31:44 -0700
commit1c2bf8a6b045a6ac4e75a7a07fde70db63e5a380 (patch)
tree8bf7f1b2e759dd2f19e65aa636cb0f11a71aa8de
parentd338d8789e64b2d8ed2f82f9364c415d6efa118d (diff)
KVM: x86/pmu: Constrain the num of guest counters with kvm_pmu_cap
Cap the number of general purpose counters enumerated on AMD to what KVM actually supports, i.e. don't allow userspace to coerce KVM into thinking there are more counters than actually exist, e.g. by enumerating X86_FEATURE_PERFCTR_CORE in guest CPUID when its not supported. Suggested-by: Sean Christopherson <[email protected]> Signed-off-by: Like Xu <[email protected]> [sean: massage changelog] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sean Christopherson <[email protected]>
-rw-r--r--arch/x86/kvm/svm/pmu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index e5c69062a909..c03958063a76 100644
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -170,6 +170,9 @@ static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
else
pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
+ pmu->nr_arch_gp_counters = min_t(unsigned int, pmu->nr_arch_gp_counters,
+ kvm_pmu_cap.num_counters_gp);
+
pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
pmu->reserved_bits = 0xfffffff000280000ull;
pmu->raw_event_mask = AMD64_RAW_EVENT_MASK;