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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * vmx_apic_access_test4 *5 * Copyright (C) 2020, Google LLC.6 *7 * This work is licensed under the terms of the GNU GPL, version 2.8 *9 * The first subtest simply checks to see that an L2 guest can be10 * launched with a valid APIC-access address that is backed by a11 * page of L1 physical memory.12 *13 * The second subtest sets the APIC-access address to a (valid) L114 * physical address that is not backed by memory. KVM can't handle15 * this situation, so resuming L2 should result in a KVM exit for16 * internal error (emulation). This is not an architectural17 * requirement. It is just a shortcoming of KVM. The internal error18 * is unfortunate, but it's better than what used to happen!19 */20 21#include "test_util.h"22#include "kvm_util.h"23#include "processor.h"24#include "vmx.h"25 26#include <string.h>27#include <sys/ioctl.h>28 29#include "kselftest.h"30 31static void l2_guest_code(void)32{33 /* Exit to L1 */34 __asm__ __volatile__("vmcall");35}36 37static void l1_guest_code(struct vmx_pages *vmx_pages, unsigned long high_gpa)38{39#define L2_GUEST_STACK_SIZE 6440 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];41 uint32_t control;42 43 GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));44 GUEST_ASSERT(load_vmcs(vmx_pages));45 46 /* Prepare the VMCS for L2 execution. */47 prepare_vmcs(vmx_pages, l2_guest_code,48 &l2_guest_stack[L2_GUEST_STACK_SIZE]);49 control = vmreadz(CPU_BASED_VM_EXEC_CONTROL);50 control |= CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;51 vmwrite(CPU_BASED_VM_EXEC_CONTROL, control);52 control = vmreadz(SECONDARY_VM_EXEC_CONTROL);53 control |= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;54 vmwrite(SECONDARY_VM_EXEC_CONTROL, control);55 vmwrite(APIC_ACCESS_ADDR, vmx_pages->apic_access_gpa);56 57 /* Try to launch L2 with the memory-backed APIC-access address. */58 GUEST_SYNC(vmreadz(APIC_ACCESS_ADDR));59 GUEST_ASSERT(!vmlaunch());60 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);61 62 vmwrite(APIC_ACCESS_ADDR, high_gpa);63 64 /* Try to resume L2 with the unbacked APIC-access address. */65 GUEST_SYNC(vmreadz(APIC_ACCESS_ADDR));66 GUEST_ASSERT(!vmresume());67 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);68 69 GUEST_DONE();70}71 72int main(int argc, char *argv[])73{74 unsigned long apic_access_addr = ~0ul;75 vm_vaddr_t vmx_pages_gva;76 unsigned long high_gpa;77 struct vmx_pages *vmx;78 bool done = false;79 80 struct kvm_vcpu *vcpu;81 struct kvm_vm *vm;82 83 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));84 85 vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);86 87 high_gpa = (vm->max_gfn - 1) << vm->page_shift;88 89 vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva);90 prepare_virtualize_apic_accesses(vmx, vm);91 vcpu_args_set(vcpu, 2, vmx_pages_gva, high_gpa);92 93 while (!done) {94 volatile struct kvm_run *run = vcpu->run;95 struct ucall uc;96 97 vcpu_run(vcpu);98 if (apic_access_addr == high_gpa) {99 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTERNAL_ERROR);100 TEST_ASSERT(run->internal.suberror ==101 KVM_INTERNAL_ERROR_EMULATION,102 "Got internal suberror other than KVM_INTERNAL_ERROR_EMULATION: %u",103 run->internal.suberror);104 break;105 }106 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);107 108 switch (get_ucall(vcpu, &uc)) {109 case UCALL_ABORT:110 REPORT_GUEST_ASSERT(uc);111 /* NOT REACHED */112 case UCALL_SYNC:113 apic_access_addr = uc.args[1];114 break;115 case UCALL_DONE:116 done = true;117 break;118 default:119 TEST_ASSERT(false, "Unknown ucall %lu", uc.cmd);120 }121 }122 kvm_vm_free(vm);123 return 0;124}125