// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2025, Google LLC.
 *
 * This test verifies that L1 fails to enter L2 with an invalid CR3, and
 * succeeds otherwise.
 */
#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)
{
        vmcall();
}

static void l1_svm_code(struct svm_test_data *svm)
{
        unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
        uintptr_t save_cr3;

        generic_svm_setup(svm, l2_guest_code,
                          &l2_guest_stack[L2_GUEST_STACK_SIZE]);

        /* Try to run L2 with invalid CR3 and make sure it fails */
        save_cr3 = svm->vmcb->save.cr3;
        svm->vmcb->save.cr3 = -1ull;
        run_guest(svm->vmcb, svm->vmcb_gpa);
        GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_ERR);

        /* Now restore CR3 and make sure L2 runs successfully */
        svm->vmcb->save.cr3 = save_cr3;
        run_guest(svm->vmcb, svm->vmcb_gpa);
        GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_VMMCALL);

        GUEST_DONE();
}

static void l1_vmx_code(struct vmx_pages *vmx_pages)
{
        unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
        uintptr_t save_cr3;

        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]);

        /* Try to run L2 with invalid CR3 and make sure it fails */
        save_cr3 = vmreadz(GUEST_CR3);
        vmwrite(GUEST_CR3, -1ull);
        GUEST_ASSERT(!vmlaunch());
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) ==
                     (EXIT_REASON_FAILED_VMENTRY | EXIT_REASON_INVALID_STATE));

        /* Now restore CR3 and make sure L2 runs successfully */
        vmwrite(GUEST_CR3, save_cr3);
        GUEST_ASSERT(!vmlaunch());
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

        GUEST_DONE();
}

static void l1_guest_code(void *data)
{
        if (this_cpu_has(X86_FEATURE_VMX))
                l1_vmx_code(data);
        else
                l1_svm_code(data);
}

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

        TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX) ||
                     kvm_cpu_has(X86_FEATURE_SVM));

        vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);

        if (kvm_cpu_has(X86_FEATURE_VMX))
                vcpu_alloc_vmx(vm, &guest_gva);
        else
                vcpu_alloc_svm(vm, &guest_gva);

        vcpu_args_set(vcpu, 1, guest_gva);

        for (;;) {
                struct ucall uc;

                vcpu_run(vcpu);
                TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

                switch (get_ucall(vcpu, &uc)) {
                case UCALL_ABORT:
                        REPORT_GUEST_ASSERT(uc);
                case UCALL_SYNC:
                        break;
                case UCALL_DONE:
                        goto done;
                default:
                        TEST_FAIL("Unknown ucall %lu", uc.cmd);
                }
        }

done:
        kvm_vm_free(vm);
        return 0;
}