Track the mask of "unavailable" PMU events as a 32-bit value. While bits
31:9 are currently reserved, silently truncating those bits is unnecessary
and asking for missed coverage. To avoid running afoul of the sanity check
in vcpu_set_cpuid_property(), explicitly adjust the mask based on the
non-reserved bits as reported by KVM's supported CPUID.
Opportunistically update the "all ones" testcase to pass -1u instead of
0xff.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
tools/testing/selftests/kvm/x86/pmu_counters_test.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86/pmu_counters_test.c b/tools/testing/selftests/kvm/x86/pmu_counters_test.c
index 8aaaf25b6111..cfeed0103341 100644
--- a/tools/testing/selftests/kvm/x86/pmu_counters_test.c
+++ b/tools/testing/selftests/kvm/x86/pmu_counters_test.c
@@ -311,7 +311,7 @@ static void guest_test_arch_events(void)
}
static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities,
- uint8_t length, uint8_t unavailable_mask)
+ uint8_t length, uint32_t unavailable_mask)
{
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
@@ -320,6 +320,9 @@ static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities,
if (!pmu_version)
return;
+ unavailable_mask = GENMASK(X86_PROPERTY_PMU_EVENTS_MASK.hi_bit,
+ X86_PROPERTY_PMU_EVENTS_MASK.lo_bit);
+
vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_test_arch_events,
pmu_version, perf_capabilities);
@@ -630,7 +633,7 @@ static void test_intel_counters(void)
*/
for (j = 0; j <= NR_INTEL_ARCH_EVENTS + 1; j++) {
test_arch_events(v, perf_caps[i], j, 0);
- test_arch_events(v, perf_caps[i], j, 0xff);
+ test_arch_events(v, perf_caps[i], j, -1u);
for (k = 0; k < NR_INTEL_ARCH_EVENTS; k++)
test_arch_events(v, perf_caps[i], j, BIT(k));
--
2.51.0.470.ga7dc726c21-goog
On 9/19/2025 8:45 AM, Sean Christopherson wrote: > Track the mask of "unavailable" PMU events as a 32-bit value. While bits > 31:9 are currently reserved, silently truncating those bits is unnecessary > and asking for missed coverage. To avoid running afoul of the sanity check > in vcpu_set_cpuid_property(), explicitly adjust the mask based on the > non-reserved bits as reported by KVM's supported CPUID. > > Opportunistically update the "all ones" testcase to pass -1u instead of > 0xff. > > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > tools/testing/selftests/kvm/x86/pmu_counters_test.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/kvm/x86/pmu_counters_test.c b/tools/testing/selftests/kvm/x86/pmu_counters_test.c > index 8aaaf25b6111..cfeed0103341 100644 > --- a/tools/testing/selftests/kvm/x86/pmu_counters_test.c > +++ b/tools/testing/selftests/kvm/x86/pmu_counters_test.c > @@ -311,7 +311,7 @@ static void guest_test_arch_events(void) > } > > static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities, > - uint8_t length, uint8_t unavailable_mask) > + uint8_t length, uint32_t unavailable_mask) > { > struct kvm_vcpu *vcpu; > struct kvm_vm *vm; > @@ -320,6 +320,9 @@ static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities, > if (!pmu_version) > return; > > + unavailable_mask = GENMASK(X86_PROPERTY_PMU_EVENTS_MASK.hi_bit, > + X86_PROPERTY_PMU_EVENTS_MASK.lo_bit); Should be "unavailable_mask &="? Otherwise the incoming argument "unavailable_mask" would be overwritten unconditionally. > + > vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_test_arch_events, > pmu_version, perf_capabilities); > > @@ -630,7 +633,7 @@ static void test_intel_counters(void) > */ > for (j = 0; j <= NR_INTEL_ARCH_EVENTS + 1; j++) { > test_arch_events(v, perf_caps[i], j, 0); > - test_arch_events(v, perf_caps[i], j, 0xff); > + test_arch_events(v, perf_caps[i], j, -1u); > > for (k = 0; k < NR_INTEL_ARCH_EVENTS; k++) > test_arch_events(v, perf_caps[i], j, BIT(k));
On Fri, Sep 19, 2025, Dapeng Mi wrote: > On 9/19/2025 8:45 AM, Sean Christopherson wrote: > > diff --git a/tools/testing/selftests/kvm/x86/pmu_counters_test.c b/tools/testing/selftests/kvm/x86/pmu_counters_test.c > > index 8aaaf25b6111..cfeed0103341 100644 > > --- a/tools/testing/selftests/kvm/x86/pmu_counters_test.c > > +++ b/tools/testing/selftests/kvm/x86/pmu_counters_test.c > > @@ -311,7 +311,7 @@ static void guest_test_arch_events(void) > > } > > > > static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities, > > - uint8_t length, uint8_t unavailable_mask) > > + uint8_t length, uint32_t unavailable_mask) > > { > > struct kvm_vcpu *vcpu; > > struct kvm_vm *vm; > > @@ -320,6 +320,9 @@ static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities, > > if (!pmu_version) > > return; > > > > + unavailable_mask = GENMASK(X86_PROPERTY_PMU_EVENTS_MASK.hi_bit, > > + X86_PROPERTY_PMU_EVENTS_MASK.lo_bit); > > Should be "unavailable_mask &="? Otherwise the incoming argument > "unavailable_mask" would be overwritten unconditionally. /facepalm Yes, definitely supposed to be &=.
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