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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2018, Red Hat, Inc.
   4  *
   5  * Tests for Enlightened VMCS, including nested guest state.
   6  */
   7 #define _GNU_SOURCE /* for program_invocation_short_name */
   8 #include <fcntl.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <sys/ioctl.h>
  13
  14 #include "test_util.h"
  15
  16 #include "kvm_util.h"
  17
  18 #include "vmx.h"
  19
  20 #define VCPU_ID         5
  21 #define NMI_VECTOR      2
  22
  23 static int ud_count;
  24
  25 void enable_x2apic(void)
  26 {
  27         uint32_t spiv_reg = APIC_BASE_MSR + (APIC_SPIV >> 4);
  28
  29         wrmsr(MSR_IA32_APICBASE, rdmsr(MSR_IA32_APICBASE) |
  30               MSR_IA32_APICBASE_ENABLE | MSR_IA32_APICBASE_EXTD);
  31         wrmsr(spiv_reg, rdmsr(spiv_reg) | APIC_SPIV_APIC_ENABLED);
  32 }
  33
  34 static void guest_ud_handler(struct ex_regs *regs)
  35 {
  36         ud_count++;
  37         regs->rip += 3; /* VMLAUNCH */
  38 }
  39
  40 static void guest_nmi_handler(struct ex_regs *regs)
  41 {
  42 }
  43
  44 void l2_guest_code(void)
  45 {
  46         GUEST_SYNC(7);
  47
  48         GUEST_SYNC(8);
  49
  50         /* Forced exit to L1 upon restore */
  51         GUEST_SYNC(9);
  52
  53         /* Done, exit to L1 and never come back.  */
  54         vmcall();
  55 }
  56
  57 void guest_code(struct vmx_pages *vmx_pages)
  58 {
  59 #define L2_GUEST_STACK_SIZE 64
  60         unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
  61
  62         enable_x2apic();
  63
  64         GUEST_SYNC(1);
  65         GUEST_SYNC(2);
  66
  67         enable_vp_assist(vmx_pages->vp_assist_gpa, vmx_pages->vp_assist);
  68
  69         GUEST_ASSERT(vmx_pages->vmcs_gpa);
  70         GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
  71         GUEST_SYNC(3);
  72         GUEST_ASSERT(load_vmcs(vmx_pages));
  73         GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
  74
  75         GUEST_SYNC(4);
  76         GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
  77
  78         prepare_vmcs(vmx_pages, l2_guest_code,
  79                      &l2_guest_stack[L2_GUEST_STACK_SIZE]);
  80
  81         GUEST_SYNC(5);
  82         GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
  83         current_evmcs->revision_id = -1u;
  84         GUEST_ASSERT(vmlaunch());
  85         current_evmcs->revision_id = EVMCS_VERSION;
  86         GUEST_SYNC(6);
  87
  88         current_evmcs->pin_based_vm_exec_control |=
  89                 PIN_BASED_NMI_EXITING;
  90         GUEST_ASSERT(!vmlaunch());
  91         GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
  92
  93         /*
  94          * NMI forces L2->L1 exit, resuming L2 and hope that EVMCS is
  95          * up-to-date (RIP points where it should and not at the beginning
  96          * of l2_guest_code(). GUEST_SYNC(9) checkes that.
  97          */
  98         GUEST_ASSERT(!vmresume());
  99
 100         GUEST_SYNC(10);
 101
 102         GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
 103         GUEST_SYNC(11);
 104
 105         /* Try enlightened vmptrld with an incorrect GPA */
 106         evmcs_vmptrld(0xdeadbeef, vmx_pages->enlightened_vmcs);
 107         GUEST_ASSERT(vmlaunch());
 108         GUEST_ASSERT(ud_count == 1);
 109         GUEST_DONE();
 110 }
 111
 112 void inject_nmi(struct kvm_vm *vm)
 113 {
 114         struct kvm_vcpu_events events;
 115
 116         vcpu_events_get(vm, VCPU_ID, &events);
 117
 118         events.nmi.pending = 1;
 119         events.flags |= KVM_VCPUEVENT_VALID_NMI_PENDING;
 120
 121         vcpu_events_set(vm, VCPU_ID, &events);
 122 }
 123
 124 int main(int argc, char *argv[])
 125 {
 126         vm_vaddr_t vmx_pages_gva = 0;
 127
 128         struct kvm_regs regs1, regs2;
 129         struct kvm_vm *vm;
 130         struct kvm_run *run;
 131         struct kvm_x86_state *state;
 132         struct ucall uc;
 133         int stage;
 134
 135         /* Create VM */
 136         vm = vm_create_default(VCPU_ID, 0, guest_code);
 137
 138         if (!nested_vmx_supported() ||
 139             !kvm_check_cap(KVM_CAP_NESTED_STATE) ||
 140             !kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 141                 print_skip("Enlightened VMCS is unsupported");
 142                 exit(KSFT_SKIP);
 143         }
 144
 145         vcpu_set_hv_cpuid(vm, VCPU_ID);
 146         vcpu_enable_evmcs(vm, VCPU_ID);
 147
 148         run = vcpu_state(vm, VCPU_ID);
 149
 150         vcpu_regs_get(vm, VCPU_ID, &regs1);
 151
 152         vcpu_alloc_vmx(vm, &vmx_pages_gva);
 153         vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
 154
 155         vm_init_descriptor_tables(vm);
 156         vcpu_init_descriptor_tables(vm, VCPU_ID);
 157         vm_handle_exception(vm, UD_VECTOR, guest_ud_handler);
 158         vm_handle_exception(vm, NMI_VECTOR, guest_nmi_handler);
 159
 160         pr_info("Running L1 which uses EVMCS to run L2\n");
 161
 162         for (stage = 1;; stage++) {
 163                 _vcpu_run(vm, VCPU_ID);
 164                 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 165                             "Stage %d: unexpected exit reason: %u (%s),\n",
 166                             stage, run->exit_reason,
 167                             exit_reason_str(run->exit_reason));
 168
 169                 switch (get_ucall(vm, VCPU_ID, &uc)) {
 170                 case UCALL_ABORT:
 171                         TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
 172                                   __FILE__, uc.args[1]);
 173                         /* NOT REACHED */
 174                 case UCALL_SYNC:
 175                         break;
 176                 case UCALL_DONE:
 177                         goto done;
 178                 default:
 179                         TEST_FAIL("Unknown ucall %lu", uc.cmd);
 180                 }
 181
 182                 /* UCALL_SYNC is handled here.  */
 183                 TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
 184                             uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
 185                             stage, (ulong)uc.args[1]);
 186
 187                 state = vcpu_save_state(vm, VCPU_ID);
 188                 memset(&regs1, 0, sizeof(regs1));
 189                 vcpu_regs_get(vm, VCPU_ID, &regs1);
 190
 191                 kvm_vm_release(vm);
 192
 193                 /* Restore state in a new VM.  */
 194                 kvm_vm_restart(vm, O_RDWR);
 195                 vm_vcpu_add(vm, VCPU_ID);
 196                 vcpu_set_hv_cpuid(vm, VCPU_ID);
 197                 vcpu_enable_evmcs(vm, VCPU_ID);
 198                 vcpu_load_state(vm, VCPU_ID, state);
 199                 run = vcpu_state(vm, VCPU_ID);
 200                 free(state);
 201
 202                 memset(&regs2, 0, sizeof(regs2));
 203                 vcpu_regs_get(vm, VCPU_ID, &regs2);
 204                 TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)),
 205                             "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
 206                             (ulong) regs2.rdi, (ulong) regs2.rsi);
 207
 208                 /* Force immediate L2->L1 exit before resuming */
 209                 if (stage == 8) {
 210                         pr_info("Injecting NMI into L1 before L2 had a chance to run after restore\n");
 211                         inject_nmi(vm);
 212                 }
 213         }
 214
 215 done:
 216         kvm_vm_free(vm);
 217 }