Assert that the number of known fixed_pmc_events matches the max number of
fixed counters supported by KVM, and clean up related code.
Opportunistically extend setup_fixed_pmc_eventsel()'s use of
array_index_nospec() to cover fixed_counters, as nr_arch_fixed_counters is
set based on userspace input (but capped using KVM-controlled values).
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/pmu_intel.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index f281e634af3c..c0b0a721b97f 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -527,16 +527,17 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
static void setup_fixed_pmc_eventsel(struct kvm_pmu *pmu)
{
- size_t size = ARRAY_SIZE(fixed_pmc_events);
- struct kvm_pmc *pmc;
- u32 event;
int i;
+ BUILD_BUG_ON(ARRAY_SIZE(fixed_pmc_events) != KVM_PMC_MAX_FIXED);
+
for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
- pmc = &pmu->fixed_counters[i];
- event = fixed_pmc_events[array_index_nospec(i, size)];
+ int index = array_index_nospec(i, KVM_PMC_MAX_FIXED);
+ struct kvm_pmc *pmc = &pmu->fixed_counters[index];
+ u32 event = fixed_pmc_events[index];
+
pmc->eventsel = (intel_arch_events[event].unit_mask << 8) |
- intel_arch_events[event].eventsel;
+ intel_arch_events[event].eventsel;
}
}
@@ -597,10 +598,8 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
if (pmu->version == 1) {
pmu->nr_arch_fixed_counters = 0;
} else {
- pmu->nr_arch_fixed_counters =
- min3(ARRAY_SIZE(fixed_pmc_events),
- (size_t) edx.split.num_counters_fixed,
- (size_t)kvm_pmu_cap.num_counters_fixed);
+ pmu->nr_arch_fixed_counters = min_t(int, edx.split.num_counters_fixed,
+ kvm_pmu_cap.num_counters_fixed);
edx.split.bit_width_fixed = min_t(int, edx.split.bit_width_fixed,
kvm_pmu_cap.bit_width_fixed);
pmu->counter_bitmask[KVM_PMC_FIXED] =
--
2.41.0.162.gfafddb0af9-goog
