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From: Vipin Sharma <vipinsh@google.com>
To: seanjc@google.com, pbonzini@redhat.com, vkuznets@redhat.com,
	dmatlack@google.com
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [Patch v3 07/13] KVM: selftests: Test Hyper-V invariant TSC control
Date: Mon,  5 Dec 2022 11:14:24 -0800	[thread overview]
Message-ID: <20221205191430.2455108-8-vipinsh@google.com> (raw)
In-Reply-To: <20221205191430.2455108-1-vipinsh@google.com>

From: Vitaly Kuznetsov <vkuznets@redhat.com>

Add a test for the newly introduced Hyper-V invariant TSC control feature:
- HV_X64_MSR_TSC_INVARIANT_CONTROL is not available without
 HV_ACCESS_TSC_INVARIANT CPUID bit set and available with it.
- BIT(0) of HV_X64_MSR_TSC_INVARIANT_CONTROL controls the filtering of
architectural invariant TSC (CPUID.80000007H:EDX[8]) bit.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 .../selftests/kvm/include/x86_64/hyperv.h     |  3 ++
 .../selftests/kvm/include/x86_64/processor.h  |  1 +
 .../selftests/kvm/x86_64/hyperv_features.c    | 47 +++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86_64/hyperv.h b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
index ab455c4efc66..28eb99046475 100644
--- a/tools/testing/selftests/kvm/include/x86_64/hyperv.h
+++ b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
@@ -335,4 +335,7 @@ struct hyperv_test_pages {
 struct hyperv_test_pages *vcpu_alloc_hyperv_test_pages(struct kvm_vm *vm,
 						       vm_vaddr_t *p_hv_pages_gva);
 
+/* HV_X64_MSR_TSC_INVARIANT_CONTROL bits */
+#define HV_INVARIANT_TSC_EXPOSED               BIT_ULL(0)
+
 #endif /* !SELFTEST_KVM_HYPERV_H */
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 5d310abe6c3f..80cbb9218f19 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -134,6 +134,7 @@ struct kvm_x86_cpu_feature {
 #define	X86_FEATURE_GBPAGES		KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 26)
 #define	X86_FEATURE_RDTSCP		KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 27)
 #define	X86_FEATURE_LM			KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 29)
+#define	X86_FEATURE_INVTSC		KVM_X86_CPU_FEATURE(0x80000007, 0, EDX, 8)
 #define	X86_FEATURE_RDPRU		KVM_X86_CPU_FEATURE(0x80000008, 0, EBX, 4)
 #define	X86_FEATURE_AMD_IBPB		KVM_X86_CPU_FEATURE(0x80000008, 0, EBX, 12)
 #define	X86_FEATURE_NPT			KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 0)
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_features.c b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
index b00240963974..258267df8e2a 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_features.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
@@ -63,6 +63,16 @@ static void guest_msr(struct msr_data *msr)
 	if (msr->write)
 		GUEST_ASSERT_3(msr_val == msr->write_val, msr->idx,
 			       msr_val, msr->write_val);
+
+	/* Invariant TSC bit appears when TSC invariant control MSR is written to */
+	if (msr->idx == HV_X64_MSR_TSC_INVARIANT_CONTROL) {
+		if (!this_cpu_has(HV_ACCESS_TSC_INVARIANT))
+			GUEST_ASSERT(this_cpu_has(X86_FEATURE_INVTSC));
+		else
+			GUEST_ASSERT(this_cpu_has(X86_FEATURE_INVTSC) ==
+				     !!(msr_val & HV_INVARIANT_TSC_EXPOSED));
+	}
+
 done:
 	GUEST_DONE();
 }
@@ -118,6 +128,7 @@ static void guest_test_msrs_access(void)
 	int stage = 0;
 	vm_vaddr_t msr_gva;
 	struct msr_data *msr;
+	bool has_invtsc = kvm_cpu_has(X86_FEATURE_INVTSC);
 
 	while (true) {
 		vm = vm_create_with_one_vcpu(&vcpu, guest_msr);
@@ -435,6 +446,42 @@ static void guest_test_msrs_access(void)
 			break;
 
 		case 44:
+			/* MSR is not available when CPUID feature bit is unset */
+			if (!has_invtsc)
+				continue;
+			msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL;
+			msr->write = false;
+			msr->fault_expected = true;
+			break;
+		case 45:
+			/* MSR is vailable when CPUID feature bit is set */
+			if (!has_invtsc)
+				continue;
+			vcpu_set_cpuid_feature(vcpu, HV_ACCESS_TSC_INVARIANT);
+			msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL;
+			msr->write = false;
+			msr->fault_expected = false;
+			break;
+		case 46:
+			/* Writing bits other than 0 is forbidden */
+			if (!has_invtsc)
+				continue;
+			msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL;
+			msr->write = true;
+			msr->write_val = 0xdeadbeef;
+			msr->fault_expected = true;
+			break;
+		case 47:
+			/* Setting bit 0 enables the feature */
+			if (!has_invtsc)
+				continue;
+			msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL;
+			msr->write = true;
+			msr->write_val = 1;
+			msr->fault_expected = false;
+			break;
+
+		default:
 			kvm_vm_free(vm);
 			return;
 		}
-- 
2.39.0.rc0.267.gcb52ba06e7-goog


  parent reply	other threads:[~2022-12-05 19:15 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-05 19:14 [Patch v3 00/13] Add Hyper-v extended hypercall support in KVM Vipin Sharma
2022-12-05 19:14 ` [Patch v3 01/13] x86/hyperv: Add HV_EXPOSE_INVARIANT_TSC define Vipin Sharma
2022-12-05 19:14 ` [Patch v3 02/13] KVM: x86: Add a KVM-only leaf for CPUID_8000_0007_EDX Vipin Sharma
2022-12-05 19:14 ` [Patch v3 03/13] KVM: x86: Hyper-V invariant TSC control Vipin Sharma
2022-12-05 19:14 ` [Patch v3 04/13] KVM: selftests: Rename 'msr->available' to 'msr->fault_exepected' in hyperv_features test Vipin Sharma
2022-12-05 19:14 ` [Patch v3 05/13] KVM: selftests: Convert hyperv_features test to using KVM_X86_CPU_FEATURE() Vipin Sharma
2022-12-05 19:14 ` [Patch v3 06/13] KVM: selftests: Test that values written to Hyper-V MSRs are preserved Vipin Sharma
2022-12-05 19:14 ` Vipin Sharma [this message]
2022-12-05 19:14 ` [Patch v3 08/13] KVM: x86: hyper-v: Use common code for hypercall userspace exit Vipin Sharma
2022-12-05 19:14 ` [Patch v3 09/13] KVM: x86: hyper-v: Add extended hypercall support in Hyper-v Vipin Sharma
2022-12-05 19:14 ` [Patch v3 10/13] KVM: selftests: Test Hyper-V extended hypercall enablement Vipin Sharma
2022-12-05 19:14 ` [Patch v3 11/13] KVM: selftests: Replace hardcoded Linux OS id with HYPERV_LINUX_OS_ID Vipin Sharma
2022-12-05 19:14 ` [Patch v3 12/13] KVM: selftests: Make vCPU exit reason test assertion common Vipin Sharma
2022-12-09 21:50   ` David Matlack
2022-12-10  1:48     ` Sean Christopherson
2022-12-12 16:00       ` Vipin Sharma
2022-12-05 19:14 ` [Patch v3 13/13] KVM: selftests: Test Hyper-V extended hypercall exit to userspace Vipin Sharma
2022-12-09 22:05   ` David Matlack
2022-12-10  1:39     ` Sean Christopherson
2022-12-10 16:57       ` David Matlack

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