From c7d7c76ecf78f93b2bd7d40bccabc813c1ed0a49 Mon Sep 17 00:00:00 2001 From: Jinrong Liang Date: Tue, 9 Jan 2024 15:02:39 -0800 Subject: [PATCH] KVM: selftests: Test consistency of CPUID with num of fixed counters Extend the PMU counters test to verify KVM emulation of fixed counters in addition to general purpose counters. Fixed counters add an extra wrinkle in the form of an extra supported bitmask. Thus quoth the SDM: fixed-function performance counter 'i' is supported if ECX[i] || (EDX[4:0] > i) Test that KVM handles a counter being available through either method. Reviewed-by: Dapeng Mi Co-developed-by: Like Xu Signed-off-by: Like Xu Signed-off-by: Jinrong Liang Co-developed-by: Sean Christopherson Tested-by: Dapeng Mi Link: https://lore.kernel.org/r/20240109230250.424295-20-seanjc@google.com Signed-off-by: Sean Christopherson --- .../selftests/kvm/x86_64/pmu_counters_test.c | 60 ++++++++++++++++++- 1 file changed, 57 insertions(+), 3 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 863418842ef85..b07294af71a3b 100644 --- a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c +++ b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c @@ -290,7 +290,7 @@ __GUEST_ASSERT(expect_gp ? vector == GP_VECTOR : !vector, \ msr, expected_val, val); static void guest_rd_wr_counters(uint32_t base_msr, uint8_t nr_possible_counters, - uint8_t nr_counters) + uint8_t nr_counters, uint32_t or_mask) { uint8_t i; @@ -301,7 +301,13 @@ static void guest_rd_wr_counters(uint32_t base_msr, uint8_t nr_possible_counters */ const uint64_t test_val = 0xffff; const uint32_t msr = base_msr + i; - const bool expect_success = i < nr_counters; + + /* + * Fixed counters are supported if the counter is less than the + * number of enumerated contiguous counters *or* the counter is + * explicitly enumerated in the supported counters mask. + */ + const bool expect_success = i < nr_counters || (or_mask & BIT(i)); /* * KVM drops writes to MSR_P6_PERFCTR[0|1] if the counters are @@ -343,7 +349,7 @@ static void guest_test_gp_counters(void) else base_msr = MSR_IA32_PERFCTR0; - guest_rd_wr_counters(base_msr, MAX_NR_GP_COUNTERS, nr_gp_counters); + guest_rd_wr_counters(base_msr, MAX_NR_GP_COUNTERS, nr_gp_counters, 0); } static void test_gp_counters(uint8_t pmu_version, uint64_t perf_capabilities, @@ -363,9 +369,50 @@ static void test_gp_counters(uint8_t pmu_version, uint64_t perf_capabilities, kvm_vm_free(vm); } +static void guest_test_fixed_counters(void) +{ + uint64_t supported_bitmask = 0; + uint8_t nr_fixed_counters = 0; + + /* Fixed counters require Architectural vPMU Version 2+. */ + if (guest_get_pmu_version() >= 2) + nr_fixed_counters = this_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS); + + /* + * The supported bitmask for fixed counters was introduced in PMU + * version 5. + */ + if (guest_get_pmu_version() >= 5) + supported_bitmask = this_cpu_property(X86_PROPERTY_PMU_FIXED_COUNTERS_BITMASK); + + guest_rd_wr_counters(MSR_CORE_PERF_FIXED_CTR0, MAX_NR_FIXED_COUNTERS, + nr_fixed_counters, supported_bitmask); +} + +static void test_fixed_counters(uint8_t pmu_version, uint64_t perf_capabilities, + uint8_t nr_fixed_counters, + uint32_t supported_bitmask) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + + vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_test_fixed_counters, + pmu_version, perf_capabilities); + + vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_FIXED_COUNTERS_BITMASK, + supported_bitmask); + vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_NR_FIXED_COUNTERS, + nr_fixed_counters); + + run_vcpu(vcpu); + + kvm_vm_free(vm); +} + static void test_intel_counters(void) { uint8_t nr_arch_events = kvm_cpu_property(X86_PROPERTY_PMU_EBX_BIT_VECTOR_LENGTH); + uint8_t nr_fixed_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS); uint8_t nr_gp_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS); uint8_t pmu_version = kvm_cpu_property(X86_PROPERTY_PMU_VERSION); unsigned int i; @@ -435,6 +482,13 @@ static void test_intel_counters(void) v, perf_caps[i]); for (j = 0; j <= nr_gp_counters; j++) test_gp_counters(v, perf_caps[i], j); + + pr_info("Testing fixed counters, PMU version %u, perf_caps = %lx\n", + v, perf_caps[i]); + for (j = 0; j <= nr_fixed_counters; j++) { + for (k = 0; k <= (BIT(nr_fixed_counters) - 1); k++) + test_fixed_counters(v, perf_caps[i], j, k); + } } } } -- 2.30.2