linux-kernel - [PATCH 11/11] KVM: selftests: Enable TSC scaling in evmcs selftest

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Message-Id: <20220621155830.60115-12-vkuznets@redhat.com>
Date:   Tue, 21 Jun 2022 17:58:30 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>
Cc:     Anirudh Rayabharam <anrayabh@...ux.microsoft.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 11/11] KVM: selftests: Enable TSC scaling in evmcs selftest

The updated Enlightened VMCS v1 definition enables TSC scaling, test
that SECONDARY_EXEC_TSC_SCALING can now be enabled.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 .../testing/selftests/kvm/x86_64/evmcs_test.c | 31 +++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
index a546d1cad146..b25e6f57b41c 100644
--- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
@@ -18,6 +18,9 @@
 
 #include "vmx.h"
 
+/* Test flags */
+#define HOST_HAS_TSC_SCALING BIT(0)
+
 static int ud_count;
 
 static void guest_ud_handler(struct ex_regs *regs)
@@ -64,11 +67,14 @@ void l2_guest_code(void)
 	vmcall();
 	rdmsr_gs_base(); /* intercepted */
 
+	/* TSC scaling */
+	vmcall();
+
 	/* Done, exit to L1 and never come back.  */
 	vmcall();
 }
 
-void guest_code(struct vmx_pages *vmx_pages)
+void guest_code(struct vmx_pages *vmx_pages, u64 test_flags)
 {
 #define L2_GUEST_STACK_SIZE 64
 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
@@ -150,6 +156,18 @@ void guest_code(struct vmx_pages *vmx_pages)
 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
 	GUEST_SYNC(11);
 
+	if (test_flags & HOST_HAS_TSC_SCALING) {
+		GUEST_ASSERT((rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2) >> 32) &
+			     SECONDARY_EXEC_TSC_SCALING);
+		/* Try enabling TSC scaling */
+		vmwrite(SECONDARY_VM_EXEC_CONTROL, vmreadz(SECONDARY_VM_EXEC_CONTROL) |
+			SECONDARY_EXEC_TSC_SCALING);
+		vmwrite(TSC_MULTIPLIER, 1);
+	}
+	GUEST_ASSERT(!vmresume());
+	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
+	GUEST_SYNC(12);
+
 	/* Try enlightened vmptrld with an incorrect GPA */
 	evmcs_vmptrld(0xdeadbeef, vmx_pages->enlightened_vmcs);
 	GUEST_ASSERT(vmlaunch());
@@ -204,6 +222,7 @@ int main(int argc, char *argv[])
 	struct kvm_vm *vm;
 	struct kvm_run *run;
 	struct ucall uc;
+	u64 test_flags = 0;
 	int stage;
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
@@ -212,11 +231,19 @@ int main(int argc, char *argv[])
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE));
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS2));
 
+	if ((kvm_get_feature_msr(MSR_IA32_VMX_PROCBASED_CTLS2) >> 32) &
+	    SECONDARY_EXEC_TSC_SCALING) {
+		test_flags |= HOST_HAS_TSC_SCALING;
+		pr_info("TSC scaling is supported, adding to test\n");
+	} else {
+		pr_info("TSC scaling is not supported\n");
+	}
+
 	vcpu_set_hv_cpuid(vcpu);
 	vcpu_enable_evmcs(vcpu);
 
 	vcpu_alloc_vmx(vm, &vmx_pages_gva);
-	vcpu_args_set(vcpu, 1, vmx_pages_gva);
+	vcpu_args_set(vcpu, 2, vmx_pages_gva, test_flags);
 
 	vm_init_descriptor_tables(vm);
 	vcpu_init_descriptor_tables(vcpu);
-- 
2.35.3