From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Xiaoyao Li <xiaoyao.li@intel.com>,
Like Xu <like.xu.linux@gmail.com>
Subject: [PATCH v2 21/21] KVM: selftests: Verify LBRs are disabled if vPMU is disabled
Date: Fri, 10 Feb 2023 00:31:48 +0000 [thread overview]
Message-ID: <20230210003148.2646712-22-seanjc@google.com> (raw)
In-Reply-To: <20230210003148.2646712-1-seanjc@google.com>
Verify that disabling the guest's vPMU via CPUID also disables LBRs.
KVM has had at least one bug where LBRs would remain enabled even though
the intent was to disable everything PMU related.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
.../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 29 +++++++++++++++++++
1 file changed, 29 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 29aaa0419294..3009b3e5254d 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
@@ -204,6 +204,34 @@ static void test_immutable_perf_capabilities(union perf_capabilities host_cap)
kvm_vm_free(vm);
}
+/*
+ * Test that LBR MSRs are writable when LBRs are enabled, and then verify that
+ * disabling the vPMU via CPUID also disables LBR support. Set bits 2:0 of
+ * LBR_TOS as those bits are writable across all uarch implementations (arch
+ * LBRs will need to poke a different MSR).
+ */
+static void test_lbr_perf_capabilities(union perf_capabilities host_cap)
+{
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+ int r;
+
+ if (!host_cap.lbr_format)
+ return;
+
+ vm = vm_create_with_one_vcpu(&vcpu, NULL);
+
+ vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.capabilities);
+ vcpu_set_msr(vcpu, MSR_LBR_TOS, 7);
+
+ vcpu_clear_cpuid_entry(vcpu, X86_PROPERTY_PMU_VERSION.function);
+
+ r = _vcpu_set_msr(vcpu, MSR_LBR_TOS, 7);
+ TEST_ASSERT(!r, "Writing LBR_TOS should fail after disabling vPMU");
+
+ kvm_vm_free(vm);
+}
+
int main(int argc, char *argv[])
{
union perf_capabilities host_cap;
@@ -222,4 +250,5 @@ int main(int argc, char *argv[])
test_fungible_perf_capabilities(host_cap);
test_immutable_perf_capabilities(host_cap);
test_guest_wrmsr_perf_capabilities(host_cap);
+ test_lbr_perf_capabilities(host_cap);
}
--
2.39.1.581.gbfd45094c4-goog
prev parent reply other threads:[~2023-02-10 0:34 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-10 0:31 [PATCH v2 00/21] KVM: x86: Disallow writes to feature MSRs post-KVM_RUN Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 01/21] KVM: x86: Rename kvm_init_msr_list() to clarify it inits multiple lists Sean Christopherson
2023-02-14 6:34 ` Xiaoyao Li
2023-02-10 0:31 ` [PATCH v2 02/21] KVM: x86: Add a helper to query whether or not a vCPU has ever run Sean Christopherson
2023-02-14 6:35 ` Xiaoyao Li
2023-02-10 0:31 ` [PATCH v2 03/21] KVM: x86: Add macros to track first...last VMX feature MSRs Sean Christopherson
2023-02-14 10:48 ` Like Xu
2023-02-14 18:51 ` Sean Christopherson
2023-02-15 3:20 ` Xiaoyao Li
2023-02-10 0:31 ` [PATCH v2 04/21] KVM: x86: Generate set of VMX feature MSRs using first/last definitions Sean Christopherson
2023-02-14 6:36 ` Xiaoyao Li
2023-02-10 0:31 ` [PATCH v2 05/21] KVM: x86: Disallow writes to immutable feature MSRs after KVM_RUN Sean Christopherson
2023-02-10 13:01 ` Yu Zhang
2023-02-10 16:31 ` Sean Christopherson
2023-02-14 6:39 ` Xiaoyao Li
2023-02-14 11:39 ` Like Xu
2023-02-15 22:36 ` Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 06/21] KVM: x86/pmu: WARN and bug the VM if PMU is refreshed after vCPU has run Sean Christopherson
2023-02-15 11:53 ` Like Xu
2023-02-15 15:20 ` Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 07/21] KVM: x86/pmu: Zero out LBR capabilities during PMU refresh Sean Christopherson
2023-02-15 12:00 ` Like Xu
2023-02-15 15:17 ` Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 08/21] KVM: selftests: Split PMU caps sub-tests to avoid writing MSR after KVM_RUN Sean Christopherson
2023-02-14 7:27 ` Like Xu
2023-02-14 17:42 ` Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 09/21] KVM: selftests: Move 0/initial value PERF_CAPS checks to dedicated sub-test Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 10/21] KVM: selftests: Assert that full-width PMC writes are supported if PDCM=1 Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 11/21] KVM: selftests: Print out failing MSR and value in vcpu_set_msr() Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 12/21] KVM: selftests: Verify KVM preserves userspace writes to "durable" MSRs Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 13/21] KVM: selftests: Drop now-redundant checks on PERF_CAPABILITIES writes Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 14/21] KVM: selftests: Test all fungible features in PERF_CAPABILITIES Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 15/21] KVM: selftests: Test all immutable non-format bits " Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 16/21] KVM: selftests: Expand negative testing of guest writes to PERF_CAPABILITIES Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 17/21] KVM: selftests: Test post-KVM_RUN " Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 18/21] KVM: selftests: Drop "all done!" printf() from PERF_CAPABILITIES test Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 19/21] KVM: selftests: Refactor LBR_FMT test to avoid use of separate macro Sean Christopherson
2023-02-10 0:31 ` [PATCH v2 20/21] KVM: selftests: Add negative testcase for PEBS format in PERF_CAPABILITIES Sean Christopherson
2023-02-10 0:31 ` Sean Christopherson [this message]
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