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 #define VCPU_ID                         1
  21
  22 /* The memory slot index to track dirty pages */
  23 #define TEST_MEM_SLOT_INDEX             1
  24 #define TEST_MEM_PAGES                  3
  25
  26 /* L1 guest test virtual memory offset */
  27 #define GUEST_TEST_MEM                  0xc0000000
  28
  29 /* L2 guest test virtual memory offset */
  30 #define NESTED_TEST_MEM1                0xc0001000
  31 #define NESTED_TEST_MEM2                0xc0002000
  32
  33 static void l2_guest_code(void)
  34 {
  35         *(volatile uint64_t *)NESTED_TEST_MEM1;
  36         *(volatile uint64_t *)NESTED_TEST_MEM1 = 1;
  37         GUEST_SYNC(true);
  38         GUEST_SYNC(false);
  39
  40         *(volatile uint64_t *)NESTED_TEST_MEM2 = 1;
  41         GUEST_SYNC(true);
  42         *(volatile uint64_t *)NESTED_TEST_MEM2 = 1;
  43         GUEST_SYNC(true);
  44         GUEST_SYNC(false);
  45
  46         /* Exit to L1 and never come back.  */
  47         vmcall();
  48 }
  49
  50 void l1_guest_code(struct vmx_pages *vmx)
  51 {
  52 #define L2_GUEST_STACK_SIZE 64
  53         unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
  54
  55         GUEST_ASSERT(vmx->vmcs_gpa);
  56         GUEST_ASSERT(prepare_for_vmx_operation(vmx));
  57         GUEST_ASSERT(load_vmcs(vmx));
  58
  59         prepare_vmcs(vmx, l2_guest_code,
  60                      &l2_guest_stack[L2_GUEST_STACK_SIZE]);
  61
  62         GUEST_SYNC(false);
  63         GUEST_ASSERT(!vmlaunch());
  64         GUEST_SYNC(false);
  65         GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
  66         GUEST_DONE();
  67 }
  68
  69 int main(int argc, char *argv[])
  70 {
  71         vm_vaddr_t vmx_pages_gva = 0;
  72         struct vmx_pages *vmx;
  73         unsigned long *bmap;
  74         uint64_t *host_test_mem;
  75
  76         struct kvm_vm *vm;
  77         struct kvm_run *run;
  78         struct ucall uc;
  79         bool done = false;
  80
  81         nested_vmx_check_supported();
  82
  83         /* Create VM */
  84         vm = vm_create_default(VCPU_ID, 0, l1_guest_code);
  85         vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva);
  86         vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
  87         run = vcpu_state(vm, VCPU_ID);
  88
  89         /* Add an extra memory slot for testing dirty logging */
  90         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
  91                                     GUEST_TEST_MEM,
  92                                     TEST_MEM_SLOT_INDEX,
  93                                     TEST_MEM_PAGES,
  94                                     KVM_MEM_LOG_DIRTY_PAGES);
  95
  96         /*
  97          * Add an identity map for GVA range [0xc0000000, 0xc0002000).  This
  98          * affects both L1 and L2.  However...
  99          */
 100         virt_map(vm, GUEST_TEST_MEM, GUEST_TEST_MEM, TEST_MEM_PAGES, 0);
 101
 102         /*
 103          * ... pages in the L2 GPA range [0xc0001000, 0xc0003000) will map to
 104          * 0xc0000000.
 105          *
 106          * Note that prepare_eptp should be called only L1's GPA map is done,
 107          * meaning after the last call to virt_map.
 108          */
 109         prepare_eptp(vmx, vm, 0);
 110         nested_map_memslot(vmx, vm, 0, 0);
 111         nested_map(vmx, vm, NESTED_TEST_MEM1, GUEST_TEST_MEM, 4096, 0);
 112         nested_map(vmx, vm, NESTED_TEST_MEM2, GUEST_TEST_MEM, 4096, 0);
 113
 114         bmap = bitmap_alloc(TEST_MEM_PAGES);
 115         host_test_mem = addr_gpa2hva(vm, GUEST_TEST_MEM);
 116
 117         while (!done) {
 118                 memset(host_test_mem, 0xaa, TEST_MEM_PAGES * 4096);
 119                 _vcpu_run(vm, VCPU_ID);
 120                 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 121                             "Unexpected exit reason: %u (%s),\n",
 122                             run->exit_reason,
 123                             exit_reason_str(run->exit_reason));
 124
 125                 switch (get_ucall(vm, VCPU_ID, &uc)) {
 126                 case UCALL_ABORT:
 127                         TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
 128                                   __FILE__, uc.args[1]);
 129                         /* NOT REACHED */
 130                 case UCALL_SYNC:
 131                         /*
 132                          * The nested guest wrote at offset 0x1000 in the memslot, but the
 133                          * dirty bitmap must be filled in according to L1 GPA, not L2.
 134                          */
 135                         kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
 136                         if (uc.args[1]) {
 137                                 TEST_ASSERT(test_bit(0, bmap), "Page 0 incorrectly reported clean\n");
 138                                 TEST_ASSERT(host_test_mem[0] == 1, "Page 0 not written by guest\n");
 139                         } else {
 140                                 TEST_ASSERT(!test_bit(0, bmap), "Page 0 incorrectly reported dirty\n");
 141                                 TEST_ASSERT(host_test_mem[0] == 0xaaaaaaaaaaaaaaaaULL, "Page 0 written by guest\n");
 142                         }
 143
 144                         TEST_ASSERT(!test_bit(1, bmap), "Page 1 incorrectly reported dirty\n");
 145                         TEST_ASSERT(host_test_mem[4096 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 1 written by guest\n");
 146                         TEST_ASSERT(!test_bit(2, bmap), "Page 2 incorrectly reported dirty\n");
 147                         TEST_ASSERT(host_test_mem[8192 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 2 written by guest\n");
 148                         break;
 149                 case UCALL_DONE:
 150                         done = true;
 151                         break;
 152                 default:
 153                         TEST_FAIL("Unknown ucall %lu", uc.cmd);
 154                 }
 155         }
 156 }