180 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * KVM dirty page logging test4 *5 * Copyright (C) 2018, Red Hat, Inc.6 */7#include <stdio.h>8#include <stdlib.h>9#include <linux/bitmap.h>10#include <linux/bitops.h>11 12#include "test_util.h"13#include "kvm_util.h"14#include "processor.h"15#include "vmx.h"16 17/* The memory slot index to track dirty pages */18#define TEST_MEM_SLOT_INDEX 119#define TEST_MEM_PAGES 320 21/* L1 guest test virtual memory offset */22#define GUEST_TEST_MEM 0xc000000023 24/* L2 guest test virtual memory offset */25#define NESTED_TEST_MEM1 0xc000100026#define NESTED_TEST_MEM2 0xc000200027 28static void l2_guest_code(u64 *a, u64 *b)29{30 READ_ONCE(*a);31 WRITE_ONCE(*a, 1);32 GUEST_SYNC(true);33 GUEST_SYNC(false);34 35 WRITE_ONCE(*b, 1);36 GUEST_SYNC(true);37 WRITE_ONCE(*b, 1);38 GUEST_SYNC(true);39 GUEST_SYNC(false);40 41 /* Exit to L1 and never come back. */42 vmcall();43}44 45static void l2_guest_code_ept_enabled(void)46{47 l2_guest_code((u64 *)NESTED_TEST_MEM1, (u64 *)NESTED_TEST_MEM2);48}49 50static void l2_guest_code_ept_disabled(void)51{52 /* Access the same L1 GPAs as l2_guest_code_ept_enabled() */53 l2_guest_code((u64 *)GUEST_TEST_MEM, (u64 *)GUEST_TEST_MEM);54}55 56void l1_guest_code(struct vmx_pages *vmx)57{58#define L2_GUEST_STACK_SIZE 6459 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];60 void *l2_rip;61 62 GUEST_ASSERT(vmx->vmcs_gpa);63 GUEST_ASSERT(prepare_for_vmx_operation(vmx));64 GUEST_ASSERT(load_vmcs(vmx));65 66 if (vmx->eptp_gpa)67 l2_rip = l2_guest_code_ept_enabled;68 else69 l2_rip = l2_guest_code_ept_disabled;70 71 prepare_vmcs(vmx, l2_rip, &l2_guest_stack[L2_GUEST_STACK_SIZE]);72 73 GUEST_SYNC(false);74 GUEST_ASSERT(!vmlaunch());75 GUEST_SYNC(false);76 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);77 GUEST_DONE();78}79 80static void test_vmx_dirty_log(bool enable_ept)81{82 vm_vaddr_t vmx_pages_gva = 0;83 struct vmx_pages *vmx;84 unsigned long *bmap;85 uint64_t *host_test_mem;86 87 struct kvm_vcpu *vcpu;88 struct kvm_vm *vm;89 struct ucall uc;90 bool done = false;91 92 pr_info("Nested EPT: %s\n", enable_ept ? "enabled" : "disabled");93 94 /* Create VM */95 vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);96 vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva);97 vcpu_args_set(vcpu, 1, vmx_pages_gva);98 99 /* Add an extra memory slot for testing dirty logging */100 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,101 GUEST_TEST_MEM,102 TEST_MEM_SLOT_INDEX,103 TEST_MEM_PAGES,104 KVM_MEM_LOG_DIRTY_PAGES);105 106 /*107 * Add an identity map for GVA range [0xc0000000, 0xc0002000). This108 * affects both L1 and L2. However...109 */110 virt_map(vm, GUEST_TEST_MEM, GUEST_TEST_MEM, TEST_MEM_PAGES);111 112 /*113 * ... pages in the L2 GPA range [0xc0001000, 0xc0003000) will map to114 * 0xc0000000.115 *116 * Note that prepare_eptp should be called only L1's GPA map is done,117 * meaning after the last call to virt_map.118 *119 * When EPT is disabled, the L2 guest code will still access the same L1120 * GPAs as the EPT enabled case.121 */122 if (enable_ept) {123 prepare_eptp(vmx, vm, 0);124 nested_map_memslot(vmx, vm, 0);125 nested_map(vmx, vm, NESTED_TEST_MEM1, GUEST_TEST_MEM, 4096);126 nested_map(vmx, vm, NESTED_TEST_MEM2, GUEST_TEST_MEM, 4096);127 }128 129 bmap = bitmap_zalloc(TEST_MEM_PAGES);130 host_test_mem = addr_gpa2hva(vm, GUEST_TEST_MEM);131 132 while (!done) {133 memset(host_test_mem, 0xaa, TEST_MEM_PAGES * 4096);134 vcpu_run(vcpu);135 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);136 137 switch (get_ucall(vcpu, &uc)) {138 case UCALL_ABORT:139 REPORT_GUEST_ASSERT(uc);140 /* NOT REACHED */141 case UCALL_SYNC:142 /*143 * The nested guest wrote at offset 0x1000 in the memslot, but the144 * dirty bitmap must be filled in according to L1 GPA, not L2.145 */146 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);147 if (uc.args[1]) {148 TEST_ASSERT(test_bit(0, bmap), "Page 0 incorrectly reported clean");149 TEST_ASSERT(host_test_mem[0] == 1, "Page 0 not written by guest");150 } else {151 TEST_ASSERT(!test_bit(0, bmap), "Page 0 incorrectly reported dirty");152 TEST_ASSERT(host_test_mem[0] == 0xaaaaaaaaaaaaaaaaULL, "Page 0 written by guest");153 }154 155 TEST_ASSERT(!test_bit(1, bmap), "Page 1 incorrectly reported dirty");156 TEST_ASSERT(host_test_mem[4096 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 1 written by guest");157 TEST_ASSERT(!test_bit(2, bmap), "Page 2 incorrectly reported dirty");158 TEST_ASSERT(host_test_mem[8192 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 2 written by guest");159 break;160 case UCALL_DONE:161 done = true;162 break;163 default:164 TEST_FAIL("Unknown ucall %lu", uc.cmd);165 }166 }167}168 169int main(int argc, char *argv[])170{171 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));172 173 test_vmx_dirty_log(/*enable_ept=*/false);174 175 if (kvm_cpu_has_ept())176 test_vmx_dirty_log(/*enable_ept=*/true);177 178 return 0;179}180