On 9/1/2023 3:28 PM, Xiong Zhang wrote:
vPMU v5 adds fixed counter enumeration, which allows user space to
specify which fixed counters are supported through emulated
CPUID.0Ah.ECX.
This commit adds a test case which specify the max fixed counter
supported only, so guest can access the max fixed counter only, #GP
exception will be happen once guest access other fixed counters.
Signed-off-by: Xiong Zhang <xiong.y.zhang@xxxxxxxxx>
---
.../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 84 +++++++++++++++++++
1 file changed, 84 insertions(+)
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
index ebbcb0a3f743..e37dc39164fe 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
since we added new test cases in this file, this file is not just test
'perf_capablities' anymore, we may change the file name
vmx_pmu_caps_test.c to a more generic name like "vmx_pmu_test.c" or
something else.
@@ -18,6 +18,8 @@
#include "kvm_util.h"
#include "vmx.h"
+uint8_t fixed_counter_num;
+
union perf_capabilities {
struct {
u64 lbr_format:6;
@@ -233,6 +235,86 @@ static void test_lbr_perf_capabilities(union perf_capabilities host_cap)
kvm_vm_free(vm);
}
+static void guest_v5_code(void)
+{
+ uint8_t vector, i;
+ uint64_t val;
+
+ for (i = 0; i < fixed_counter_num; i++) {
+ vector = rdmsr_safe(MSR_CORE_PERF_FIXED_CTR0 + i, &val);
+
+ /*
+ * Only the max fixed counter is supported, #GP will be generated
+ * when guest access other fixed counters.
+ */
+ if (i == fixed_counter_num - 1)
+ __GUEST_ASSERT(vector != GP_VECTOR,
+ "Max Fixed counter is accessible, but get #GP");
+ else
+ __GUEST_ASSERT(vector == GP_VECTOR,
+ "Fixed counter isn't accessible, but access is ok");
+ }
+
+ GUEST_DONE();
+}
+
+#define PMU_NR_FIXED_COUNTERS_MASK 0x1f
+
+static void test_fixed_counter_enumeration(void)
+{
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+ int r;
+ struct kvm_cpuid_entry2 *ent;
+ struct ucall uc;
+ uint32_t fixed_counter_bit_mask;
+
+ if (kvm_cpu_property(X86_PROPERTY_PMU_VERSION) != 5)
+ return;
We'd better check if the version is less than 5 here, since we might
have higher version than 5 in the future.
+
+ vm = vm_create_with_one_vcpu(&vcpu, guest_v5_code);
+ vm_init_descriptor_tables(vm);
+ vcpu_init_descriptor_tables(vcpu);
+
+ ent = vcpu_get_cpuid_entry(vcpu, 0xa);
+ fixed_counter_num = ent->edx & PMU_NR_FIXED_COUNTERS_MASK;
+ TEST_ASSERT(fixed_counter_num > 0, "fixed counter isn't supported");
+ fixed_counter_bit_mask = (1ul << fixed_counter_num) - 1;
+ TEST_ASSERT(ent->ecx == fixed_counter_bit_mask,
+ "cpuid.0xa.ecx != %x", fixed_counter_bit_mask);
+
+ /* Fixed counter 0 isn't in ecx, but in edx, set_cpuid should be error. */
+ ent->ecx &= ~0x1;
+ r = __vcpu_set_cpuid(vcpu);
+ TEST_ASSERT(r, "Setting in-consistency cpuid.0xa.ecx and edx success");
+
+ if (fixed_counter_num == 1) {
+ kvm_vm_free(vm);
+ return;
+ }
+
+ /* Support the max Fixed Counter only */
+ ent->ecx = 1UL << (fixed_counter_num - 1);
+ ent->edx &= ~(u32)PMU_NR_FIXED_COUNTERS_MASK;
+
+ r = __vcpu_set_cpuid(vcpu);
+ TEST_ASSERT(!r, "Setting modified cpuid.0xa.ecx and edx failed");
+
+ vcpu_run(vcpu);
+
+ switch (get_ucall(vcpu, &uc)) {
+ case UCALL_ABORT:
+ REPORT_GUEST_ASSERT(uc);
+ break;
+ case UCALL_DONE:
+ break;
+ default:
+ TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+ }
+
+ kvm_vm_free(vm);
+}
+
int main(int argc, char *argv[])
{
union perf_capabilities host_cap;
@@ -253,4 +335,6 @@ int main(int argc, char *argv[])
test_immutable_perf_capabilities(host_cap);
test_guest_wrmsr_perf_capabilities(host_cap);
test_lbr_perf_capabilities(host_cap);
+
+ test_fixed_counter_enumeration();
}
