root/tools/testing/selftests/kvm/x86/svm_nested_clear_efer_svme.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2026, Google LLC.
 */
#include "kvm_util.h"
#include "vmx.h"
#include "svm_util.h"
#include "kselftest.h"


#define L2_GUEST_STACK_SIZE 64

static void l2_guest_code(void)
{
        unsigned long efer = rdmsr(MSR_EFER);

        /* generic_svm_setup() initializes EFER_SVME set for L2 */
        GUEST_ASSERT(efer & EFER_SVME);
        wrmsr(MSR_EFER, efer & ~EFER_SVME);

        /* Unreachable, L1 should be shutdown */
        GUEST_ASSERT(0);
}

static void l1_guest_code(struct svm_test_data *svm)
{
        unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];

        generic_svm_setup(svm, l2_guest_code,
                          &l2_guest_stack[L2_GUEST_STACK_SIZE]);
        run_guest(svm->vmcb, svm->vmcb_gpa);

        /* Unreachable, L1 should be shutdown */
        GUEST_ASSERT(0);
}

int main(int argc, char *argv[])
{
        struct kvm_vcpu *vcpu;
        struct kvm_vm *vm;
        gva_t nested_gva = 0;

        TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));

        vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);

        vcpu_alloc_svm(vm, &nested_gva);
        vcpu_args_set(vcpu, 1, nested_gva);

        vcpu_run(vcpu);
        TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_SHUTDOWN);

        kvm_vm_free(vm);
        return 0;
}