1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2025, Google LLC. 4 * 5 * This test verifies that L1 fails to enter L2 with an invalid CR3, and 6 * succeeds otherwise. 7 */ 8 #include "kvm_util.h" 9 #include "vmx.h" 10 #include "svm_util.h" 11 #include "kselftest.h" 12 13 14 #define L2_GUEST_STACK_SIZE 64 15 16 static void l2_guest_code(void) 17 { 18 vmcall(); 19 } 20 21 static void l1_svm_code(struct svm_test_data *svm) 22 { 23 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; 24 uintptr_t save_cr3; 25 26 generic_svm_setup(svm, l2_guest_code, 27 &l2_guest_stack[L2_GUEST_STACK_SIZE]); 28 29 /* Try to run L2 with invalid CR3 and make sure it fails */ 30 save_cr3 = svm->vmcb->save.cr3; 31 svm->vmcb->save.cr3 = -1ull; 32 run_guest(svm->vmcb, svm->vmcb_gpa); 33 GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_ERR); 34 35 /* Now restore CR3 and make sure L2 runs successfully */ 36 svm->vmcb->save.cr3 = save_cr3; 37 run_guest(svm->vmcb, svm->vmcb_gpa); 38 GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_VMMCALL); 39 40 GUEST_DONE(); 41 } 42 43 static void l1_vmx_code(struct vmx_pages *vmx_pages) 44 { 45 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; 46 uintptr_t save_cr3; 47 48 GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages)); 49 GUEST_ASSERT(load_vmcs(vmx_pages)); 50 51 prepare_vmcs(vmx_pages, l2_guest_code, 52 &l2_guest_stack[L2_GUEST_STACK_SIZE]); 53 54 /* Try to run L2 with invalid CR3 and make sure it fails */ 55 save_cr3 = vmreadz(GUEST_CR3); 56 vmwrite(GUEST_CR3, -1ull); 57 GUEST_ASSERT(!vmlaunch()); 58 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == 59 (EXIT_REASON_FAILED_VMENTRY | EXIT_REASON_INVALID_STATE)); 60 61 /* Now restore CR3 and make sure L2 runs successfully */ 62 vmwrite(GUEST_CR3, save_cr3); 63 GUEST_ASSERT(!vmlaunch()); 64 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); 65 66 GUEST_DONE(); 67 } 68 69 static void l1_guest_code(void *data) 70 { 71 if (this_cpu_has(X86_FEATURE_VMX)) 72 l1_vmx_code(data); 73 else 74 l1_svm_code(data); 75 } 76 77 int main(int argc, char *argv[]) 78 { 79 struct kvm_vcpu *vcpu; 80 struct kvm_vm *vm; 81 vm_vaddr_t guest_gva = 0; 82 83 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX) || 84 kvm_cpu_has(X86_FEATURE_SVM)); 85 86 vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code); 87 88 if (kvm_cpu_has(X86_FEATURE_VMX)) 89 vcpu_alloc_vmx(vm, &guest_gva); 90 else 91 vcpu_alloc_svm(vm, &guest_gva); 92 93 vcpu_args_set(vcpu, 1, guest_gva); 94 95 for (;;) { 96 struct ucall uc; 97 98 vcpu_run(vcpu); 99 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); 100 101 switch (get_ucall(vcpu, &uc)) { 102 case UCALL_ABORT: 103 REPORT_GUEST_ASSERT(uc); 104 case UCALL_SYNC: 105 break; 106 case UCALL_DONE: 107 goto done; 108 default: 109 TEST_FAIL("Unknown ucall %lu", uc.cmd); 110 } 111 } 112 113 done: 114 kvm_vm_free(vm); 115 return 0; 116 } 117