tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * KVM dirty page logging test
   4  *
   5  * Copyright (C) 2018, Red Hat, Inc.
   6  */
   7
   8 #define _GNU_SOURCE /* for program_invocation_name */
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <linux/bitmap.h>
  13 #include <linux/bitops.h>
  14
  15 #include "test_util.h"
  16 #include "kvm_util.h"
  17 #include "processor.h"
  18 #include "vmx.h"
  19
  20 /* The memory slot index to track dirty pages */
  21 #define TEST_MEM_SLOT_INDEX             1
  22 #define TEST_MEM_PAGES                  3
  23
  24 /* L1 guest test virtual memory offset */
  25 #define GUEST_TEST_MEM                  0xc0000000
  26
  27 /* L2 guest test virtual memory offset */
  28 #define NESTED_TEST_MEM1                0xc0001000
  29 #define NESTED_TEST_MEM2                0xc0002000
  30
  31 static void l2_guest_code(void)
  32 {
  33         *(volatile uint64_t *)NESTED_TEST_MEM1;
  34         *(volatile uint64_t *)NESTED_TEST_MEM1 = 1;
  35         GUEST_SYNC(true);
  36         GUEST_SYNC(false);
  37
  38         *(volatile uint64_t *)NESTED_TEST_MEM2 = 1;
  39         GUEST_SYNC(true);
  40         *(volatile uint64_t *)NESTED_TEST_MEM2 = 1;
  41         GUEST_SYNC(true);
  42         GUEST_SYNC(false);
  43
  44         /* Exit to L1 and never come back.  */
  45         vmcall();
  46 }
  47
  48 void l1_guest_code(struct vmx_pages *vmx)
  49 {
  50 #define L2_GUEST_STACK_SIZE 64
  51         unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
  52
  53         GUEST_ASSERT(vmx->vmcs_gpa);
  54         GUEST_ASSERT(prepare_for_vmx_operation(vmx));
  55         GUEST_ASSERT(load_vmcs(vmx));
  56
  57         prepare_vmcs(vmx, l2_guest_code,
  58                      &l2_guest_stack[L2_GUEST_STACK_SIZE]);
  59
  60         GUEST_SYNC(false);
  61         GUEST_ASSERT(!vmlaunch());
  62         GUEST_SYNC(false);
  63         GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
  64         GUEST_DONE();
  65 }
  66
  67 int main(int argc, char *argv[])
  68 {
  69         vm_vaddr_t vmx_pages_gva = 0;
  70         struct vmx_pages *vmx;
  71         unsigned long *bmap;
  72         uint64_t *host_test_mem;
  73
  74         struct kvm_vcpu *vcpu;
  75         struct kvm_vm *vm;
  76         struct ucall uc;
  77         bool done = false;
  78
  79         TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
  80         TEST_REQUIRE(kvm_cpu_has_ept());
  81
  82         /* Create VM */
  83         vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
  84         vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva);
  85         vcpu_args_set(vcpu, 1, vmx_pages_gva);
  86
  87         /* Add an extra memory slot for testing dirty logging */
  88         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
  89                                     GUEST_TEST_MEM,
  90                                     TEST_MEM_SLOT_INDEX,
  91                                     TEST_MEM_PAGES,
  92                                     KVM_MEM_LOG_DIRTY_PAGES);
  93
  94         /*
  95          * Add an identity map for GVA range [0xc0000000, 0xc0002000).  This
  96          * affects both L1 and L2.  However...
  97          */
  98         virt_map(vm, GUEST_TEST_MEM, GUEST_TEST_MEM, TEST_MEM_PAGES);
  99
 100         /*
 101          * ... pages in the L2 GPA range [0xc0001000, 0xc0003000) will map to
 102          * 0xc0000000.
 103          *
 104          * Note that prepare_eptp should be called only L1's GPA map is done,
 105          * meaning after the last call to virt_map.
 106          */
 107         prepare_eptp(vmx, vm, 0);
 108         nested_map_memslot(vmx, vm, 0);
 109         nested_map(vmx, vm, NESTED_TEST_MEM1, GUEST_TEST_MEM, 4096);
 110         nested_map(vmx, vm, NESTED_TEST_MEM2, GUEST_TEST_MEM, 4096);
 111
 112         bmap = bitmap_zalloc(TEST_MEM_PAGES);
 113         host_test_mem = addr_gpa2hva(vm, GUEST_TEST_MEM);
 114
 115         while (!done) {
 116                 memset(host_test_mem, 0xaa, TEST_MEM_PAGES * 4096);
 117                 vcpu_run(vcpu);
 118                 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
 119
 120                 switch (get_ucall(vcpu, &uc)) {
 121                 case UCALL_ABORT:
 122                         REPORT_GUEST_ASSERT(uc);
 123                         /* NOT REACHED */
 124                 case UCALL_SYNC:
 125                         /*
 126                          * The nested guest wrote at offset 0x1000 in the memslot, but the
 127                          * dirty bitmap must be filled in according to L1 GPA, not L2.
 128                          */
 129                         kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
 130                         if (uc.args[1]) {
 131                                 TEST_ASSERT(test_bit(0, bmap), "Page 0 incorrectly reported clean");
 132                                 TEST_ASSERT(host_test_mem[0] == 1, "Page 0 not written by guest");
 133                         } else {
 134                                 TEST_ASSERT(!test_bit(0, bmap), "Page 0 incorrectly reported dirty");
 135                                 TEST_ASSERT(host_test_mem[0] == 0xaaaaaaaaaaaaaaaaULL, "Page 0 written by guest");
 136                         }
 137
 138                         TEST_ASSERT(!test_bit(1, bmap), "Page 1 incorrectly reported dirty");
 139                         TEST_ASSERT(host_test_mem[4096 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 1 written by guest");
 140                         TEST_ASSERT(!test_bit(2, bmap), "Page 2 incorrectly reported dirty");
 141                         TEST_ASSERT(host_test_mem[8192 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 2 written by guest");
 142                         break;
 143                 case UCALL_DONE:
 144                         done = true;
 145                         break;
 146                 default:
 147                         TEST_FAIL("Unknown ucall %lu", uc.cmd);
 148                 }
 149         }
 150 }