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Diffstat (limited to 'tools/testing/selftests/kvm/x86_64/pmu_counters_test.c')
-rw-r--r--tools/testing/selftests/kvm/x86_64/pmu_counters_test.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
index 29609b52f8fa0..26c85815f7e98 100644
--- a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
+++ b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
@@ -416,12 +416,30 @@ static void guest_rd_wr_counters(uint32_t base_msr, uint8_t nr_possible_counters
static void guest_test_gp_counters(void)
{
+ uint8_t pmu_version = guest_get_pmu_version();
uint8_t nr_gp_counters = 0;
uint32_t base_msr;
- if (guest_get_pmu_version())
+ if (pmu_version)
nr_gp_counters = this_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS);
+ /*
+ * For v2+ PMUs, PERF_GLOBAL_CTRL's architectural post-RESET value is
+ * "Sets bits n-1:0 and clears the upper bits", where 'n' is the number
+ * of GP counters. If there are no GP counters, require KVM to leave
+ * PERF_GLOBAL_CTRL '0'. This edge case isn't covered by the SDM, but
+ * follow the spirit of the architecture and only globally enable GP
+ * counters, of which there are none.
+ */
+ if (pmu_version > 1) {
+ uint64_t global_ctrl = rdmsr(MSR_CORE_PERF_GLOBAL_CTRL);
+
+ if (nr_gp_counters)
+ GUEST_ASSERT_EQ(global_ctrl, GENMASK_ULL(nr_gp_counters - 1, 0));
+ else
+ GUEST_ASSERT_EQ(global_ctrl, 0);
+ }
+
if (this_cpu_has(X86_FEATURE_PDCM) &&
rdmsr(MSR_IA32_PERF_CAPABILITIES) & PMU_CAP_FW_WRITES)
base_msr = MSR_IA32_PMC0;