KVM: selftests: Extend vmx_tsc_adjust_test to cover SVM

Add SVM L1 code to run the nested guest, and allow the test to run with
SVM as well as VMX.

Reviewed-by: Jim Mattson <jmattson@google.com>

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-8-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: yosrym93

tools/testing/selftests/kvm/Makefile.kvm

@@ -92,6 +92,7 @@ TEST_GEN_PROGS_x86 += x86/nested_close_kvm_test
 TEST_GEN_PROGS_x86 += x86/nested_emulation_test
 TEST_GEN_PROGS_x86 += x86/nested_exceptions_test
 TEST_GEN_PROGS_x86 += x86/nested_invalid_cr3_test
+TEST_GEN_PROGS_x86 += x86/nested_tsc_adjust_test
 TEST_GEN_PROGS_x86 += x86/nested_tsc_scaling_test
 TEST_GEN_PROGS_x86 += x86/platform_info_test
 TEST_GEN_PROGS_x86 += x86/pmu_counters_test
@@ -119,7 +120,6 @@ TEST_GEN_PROGS_x86 += x86/vmx_exception_with_invalid_guest_state
 TEST_GEN_PROGS_x86 += x86/vmx_msrs_test
 TEST_GEN_PROGS_x86 += x86/vmx_invalid_nested_guest_state
 TEST_GEN_PROGS_x86 += x86/vmx_set_nested_state_test
-TEST_GEN_PROGS_x86 += x86/vmx_tsc_adjust_test
 TEST_GEN_PROGS_x86 += x86/apic_bus_clock_test
 TEST_GEN_PROGS_x86 += x86/xapic_ipi_test
 TEST_GEN_PROGS_x86 += x86/xapic_state_test

tools/testing/selftests/kvm/x86/vmx_tsc_adjust_test.c renamed to tools/testing/selftests/kvm/x86/nested_tsc_adjust_test.c

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * vmx_tsc_adjust_test
- *
  * Copyright (C) 2018, Google LLC.
  *
  * IA32_TSC_ADJUST test
@@ -22,6 +20,7 @@
 #include "kvm_util.h"
 #include "processor.h"
 #include "vmx.h"
+#include "svm_util.h"
 
 #include <string.h>
 #include <sys/ioctl.h>
@@ -35,6 +34,8 @@
 #define TSC_ADJUST_VALUE (1ll << 32)
 #define TSC_OFFSET_VALUE -(1ll << 48)
 
+#define L2_GUEST_STACK_SIZE 64
+
 enum {
 	PORT_ABORT = 0x1000,
 	PORT_REPORT,
@@ -72,32 +73,47 @@ static void l2_guest_code(void)
 	__asm__ __volatile__("vmcall");
 }
 
-static void l1_guest_code(struct vmx_pages *vmx_pages)
+static void l1_guest_code(void *data)
 {
-#define L2_GUEST_STACK_SIZE 64
 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
-	uint32_t control;
 
+	/* Set TSC from L1 and make sure TSC_ADJUST is updated correctly */
 	GUEST_ASSERT(rdtsc() < TSC_ADJUST_VALUE);
 	wrmsr(MSR_IA32_TSC, rdtsc() - TSC_ADJUST_VALUE);
 	check_ia32_tsc_adjust(-1 * TSC_ADJUST_VALUE);
 
-	GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
-	GUEST_ASSERT(load_vmcs(vmx_pages));
-
-	/* Prepare the VMCS for L2 execution. */
-	prepare_vmcs(vmx_pages, l2_guest_code,
-		     &l2_guest_stack[L2_GUEST_STACK_SIZE]);
-	control = vmreadz(CPU_BASED_VM_EXEC_CONTROL);
-	control |= CPU_BASED_USE_MSR_BITMAPS | CPU_BASED_USE_TSC_OFFSETTING;
-	vmwrite(CPU_BASED_VM_EXEC_CONTROL, control);
-	vmwrite(TSC_OFFSET, TSC_OFFSET_VALUE);
-
-	GUEST_ASSERT(!vmlaunch());
-	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
+	/*
+	 * Run L2 with TSC_OFFSET. L2 will write to TSC, and L1 is not
+	 * intercepting the write so it should update L1's TSC_ADJUST.
+	 */
+	if (this_cpu_has(X86_FEATURE_VMX)) {
+		struct vmx_pages *vmx_pages = data;
+		uint32_t control;
+
+		GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
+		GUEST_ASSERT(load_vmcs(vmx_pages));
+
+		prepare_vmcs(vmx_pages, l2_guest_code,
+			     &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+		control = vmreadz(CPU_BASED_VM_EXEC_CONTROL);
+		control |= CPU_BASED_USE_MSR_BITMAPS | CPU_BASED_USE_TSC_OFFSETTING;
+		vmwrite(CPU_BASED_VM_EXEC_CONTROL, control);
+		vmwrite(TSC_OFFSET, TSC_OFFSET_VALUE);
+
+		GUEST_ASSERT(!vmlaunch());
+		GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
+	} else {
+		struct svm_test_data *svm = data;
+
+		generic_svm_setup(svm, l2_guest_code,
+				  &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+
+		svm->vmcb->control.tsc_offset = TSC_OFFSET_VALUE;
+		run_guest(svm->vmcb, svm->vmcb_gpa);
+		GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_VMMCALL);
+	}
 
 	check_ia32_tsc_adjust(-2 * TSC_ADJUST_VALUE);
-
 	GUEST_DONE();
 }
 
@@ -109,16 +125,19 @@ static void report(int64_t val)
 
 int main(int argc, char *argv[])
 {
-	vm_vaddr_t vmx_pages_gva;
+	vm_vaddr_t nested_gva;
 	struct kvm_vcpu *vcpu;
 
-	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
+	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX) ||
+		     kvm_cpu_has(X86_FEATURE_SVM));
 
-	vm = vm_create_with_one_vcpu(&vcpu, (void *) l1_guest_code);
+	vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
+	if (kvm_cpu_has(X86_FEATURE_VMX))
+		vcpu_alloc_vmx(vm, &nested_gva);
+	else
+		vcpu_alloc_svm(vm, &nested_gva);
 
-	/* Allocate VMX pages and shared descriptors (vmx_pages). */
-	vcpu_alloc_vmx(vm, &vmx_pages_gva);
-	vcpu_args_set(vcpu, 1, vmx_pages_gva);
+	vcpu_args_set(vcpu, 1, nested_gva);
 
 	for (;;) {
 		struct ucall uc;