linux-kernel - [PATCH v3 07/11] KVM: selftests: Test Intel supported fixed counters bit mask

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Date:   Mon, 14 Aug 2023 19:51:04 +0800
From:   Jinrong Liang <ljr.kernel@...il.com>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     Paolo Bonzini <pbonzini@...hat.com>, Like Xu <likexu@...cent.com>,
        David Matlack <dmatlack@...gle.com>,
        Aaron Lewis <aaronlewis@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jinrong Liang <cloudliang@...cent.com>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 07/11] KVM: selftests: Test Intel supported fixed counters bit mask

From: Jinrong Liang <cloudliang@...cent.com>

Add a test to check that fixed counters enabled via guest
CPUID.0xA.ECX (instead of EDX[04:00]) work as normal as usual.

Co-developed-by: Like Xu <likexu@...cent.com>
Signed-off-by: Like Xu <likexu@...cent.com>
Signed-off-by: Jinrong Liang <cloudliang@...cent.com>
---
 .../kvm/x86_64/pmu_basic_functionality_test.c | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c b/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
index db1c1230700a..3bbf3bd2846b 100644
--- a/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
+++ b/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
@@ -282,6 +282,65 @@ static void intel_test_counters_num(void)
 	}
 }
 
+static void intel_guest_run_fixed_counters(void)
+{
+	uint64_t supported_bitmask = this_cpu_property(X86_PROPERTY_PMU_FIXED_COUNTERS_BITMASK);
+	uint32_t nr_fixed_counter = this_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS);
+	uint64_t msr_val;
+	unsigned int i;
+	bool expected;
+
+	for (i = 0; i < nr_fixed_counter; i++) {
+		expected = supported_bitmask & BIT_ULL(i) || i < nr_fixed_counter;
+
+		wrmsr_safe(MSR_CORE_PERF_FIXED_CTR0 + i, 0);
+		wrmsr_safe(MSR_CORE_PERF_FIXED_CTR_CTRL, BIT_ULL(4 * i));
+		wrmsr_safe(MSR_CORE_PERF_GLOBAL_CTRL, BIT_ULL(INTEL_PMC_IDX_FIXED + i));
+		__asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES}));
+		wrmsr_safe(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+		rdmsr_safe(MSR_CORE_PERF_FIXED_CTR0 + i, &msr_val);
+
+		GUEST_ASSERT(expected == !!msr_val);
+	}
+
+	GUEST_DONE();
+}
+
+static void test_fixed_counters_setup(struct kvm_vcpu *vcpu,
+				      uint32_t fixed_bitmask,
+				      uint8_t edx_fixed_num)
+{
+	int ret;
+
+	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_FIXED_COUNTERS_BITMASK,
+				fixed_bitmask);
+	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_NR_FIXED_COUNTERS,
+				edx_fixed_num);
+
+	do {
+		ret = run_vcpu(vcpu, NULL);
+	} while (ret != UCALL_DONE);
+}
+
+static void intel_test_fixed_counters(void)
+{
+	uint8_t nr_fixed_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS);
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	uint32_t ecx;
+	uint8_t edx;
+
+	for (edx = 0; edx <= nr_fixed_counters; edx++) {
+		/* KVM doesn't emulate more fixed counters than it can support. */
+		for (ecx = 0; ecx <= (BIT_ULL(nr_fixed_counters) - 1); ecx++) {
+			vm = pmu_vm_create_with_one_vcpu(&vcpu,
+							 intel_guest_run_fixed_counters);
+			test_fixed_counters_setup(vcpu, ecx, edx);
+			kvm_vm_free(vm);
+		}
+	}
+}
+
 int main(int argc, char *argv[])
 {
 	TEST_REQUIRE(get_kvm_param_bool("enable_pmu"));
@@ -293,6 +352,7 @@ int main(int argc, char *argv[])
 
 	intel_test_arch_events();
 	intel_test_counters_num();
+	intel_test_fixed_counters();
 
 	return 0;
 }
-- 
2.39.3