LXR linux/tools/testing/selftests/kvm/x86_64/sync_regs

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Test for x86 KVM_CAP_SYNC_REGS
   4 *
   5 * Copyright (C) 2018, Google LLC.
   6 *
   7 * Verifies expected behavior of x86 KVM_CAP_SYNC_REGS functionality,
   8 * including requesting an invalid register set, updates to/from values
   9 * in kvm_run.s.regs when kvm_valid_regs and kvm_dirty_regs are toggled.
  10 */
  11
  12#define _GNU_SOURCE /* for program_invocation_short_name */
  13#include <fcntl.h>
  14#include <stdio.h>
  15#include <stdlib.h>
  16#include <string.h>
  17#include <sys/ioctl.h>
  18
  19#include "test_util.h"
  20#include "kvm_util.h"
  21#include "processor.h"
  22
  23#define VCPU_ID 5
  24
  25#define UCALL_PIO_PORT ((uint16_t)0x1000)
  26
  27struct ucall uc_none = {
  28        .cmd = UCALL_NONE,
  29};
  30
  31/*
  32 * ucall is embedded here to protect against compiler reshuffling registers
  33 * before calling a function. In this test we only need to get KVM_EXIT_IO
  34 * vmexit and preserve RBX, no additional information is needed.
  35 */
  36void guest_code(void)
  37{
  38        asm volatile("1: in %[port], %%al\n"
  39                     "add $0x1, %%rbx\n"
  40                     "jmp 1b"
  41                     : : [port] "d" (UCALL_PIO_PORT), "D" (&uc_none)
  42                     : "rax", "rbx");
  43}
  44
  45static void compare_regs(struct kvm_regs *left, struct kvm_regs *right)
  46{
  47#define REG_COMPARE(reg) \
  48        TEST_ASSERT(left->reg == right->reg, \
  49                    "Register " #reg \
  50                    " values did not match: 0x%llx, 0x%llx\n", \
  51                    left->reg, right->reg)
  52        REG_COMPARE(rax);
  53        REG_COMPARE(rbx);
  54        REG_COMPARE(rcx);
  55        REG_COMPARE(rdx);
  56        REG_COMPARE(rsi);
  57        REG_COMPARE(rdi);
  58        REG_COMPARE(rsp);
  59        REG_COMPARE(rbp);
  60        REG_COMPARE(r8);
  61        REG_COMPARE(r9);
  62        REG_COMPARE(r10);
  63        REG_COMPARE(r11);
  64        REG_COMPARE(r12);
  65        REG_COMPARE(r13);
  66        REG_COMPARE(r14);
  67        REG_COMPARE(r15);
  68        REG_COMPARE(rip);
  69        REG_COMPARE(rflags);
  70#undef REG_COMPARE
  71}
  72
  73static void compare_sregs(struct kvm_sregs *left, struct kvm_sregs *right)
  74{
  75}
  76
  77static void compare_vcpu_events(struct kvm_vcpu_events *left,
  78                                struct kvm_vcpu_events *right)
  79{
  80}
  81
  82#define TEST_SYNC_FIELDS   (KVM_SYNC_X86_REGS|KVM_SYNC_X86_SREGS|KVM_SYNC_X86_EVENTS)
  83#define INVALID_SYNC_FIELD 0x80000000
  84
  85int main(int argc, char *argv[])
  86{
  87        struct kvm_vm *vm;
  88        struct kvm_run *run;
  89        struct kvm_regs regs;
  90        struct kvm_sregs sregs;
  91        struct kvm_vcpu_events events;
  92        int rv, cap;
  93
  94        /* Tell stdout not to buffer its content */
  95        setbuf(stdout, NULL);
  96
  97        cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
  98        if ((cap & TEST_SYNC_FIELDS) != TEST_SYNC_FIELDS) {
  99                print_skip("KVM_CAP_SYNC_REGS not supported");
 100                exit(KSFT_SKIP);
 101        }
 102        if ((cap & INVALID_SYNC_FIELD) != 0) {
 103                print_skip("The \"invalid\" field is not invalid");
 104                exit(KSFT_SKIP);
 105        }
 106
 107        /* Create VM */
 108        vm = vm_create_default(VCPU_ID, 0, guest_code);
 109
 110        run = vcpu_state(vm, VCPU_ID);
 111
 112        /* Request reading invalid register set from VCPU. */
 113        run->kvm_valid_regs = INVALID_SYNC_FIELD;
 114        rv = _vcpu_run(vm, VCPU_ID);
 115        TEST_ASSERT(rv < 0 && errno == EINVAL,
 116                    "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
 117                    rv);
 118        vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
 119
 120        run->kvm_valid_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
 121        rv = _vcpu_run(vm, VCPU_ID);
 122        TEST_ASSERT(rv < 0 && errno == EINVAL,
 123                    "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
 124                    rv);
 125        vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
 126
 127        /* Request setting invalid register set into VCPU. */
 128        run->kvm_dirty_regs = INVALID_SYNC_FIELD;
 129        rv = _vcpu_run(vm, VCPU_ID);
 130        TEST_ASSERT(rv < 0 && errno == EINVAL,
 131                    "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
 132                    rv);
 133        vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
 134
 135        run->kvm_dirty_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
 136        rv = _vcpu_run(vm, VCPU_ID);
 137        TEST_ASSERT(rv < 0 && errno == EINVAL,
 138                    "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
 139                    rv);
 140        vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
 141
 142        /* Request and verify all valid register sets. */
 143        /* TODO: BUILD TIME CHECK: TEST_ASSERT(KVM_SYNC_X86_NUM_FIELDS != 3); */
 144        run->kvm_valid_regs = TEST_SYNC_FIELDS;
 145        rv = _vcpu_run(vm, VCPU_ID);
 146        TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 147                    "Unexpected exit reason: %u (%s),\n",
 148                    run->exit_reason,
 149                    exit_reason_str(run->exit_reason));
 150
 151        vcpu_regs_get(vm, VCPU_ID, &regs);
 152        compare_regs(&regs, &run->s.regs.regs);
 153
 154        vcpu_sregs_get(vm, VCPU_ID, &sregs);
 155        compare_sregs(&sregs, &run->s.regs.sregs);
 156
 157        vcpu_events_get(vm, VCPU_ID, &events);
 158        compare_vcpu_events(&events, &run->s.regs.events);
 159
 160        /* Set and verify various register values. */
 161        run->s.regs.regs.rbx = 0xBAD1DEA;
 162        run->s.regs.sregs.apic_base = 1 << 11;
 163        /* TODO run->s.regs.events.XYZ = ABC; */
 164
 165        run->kvm_valid_regs = TEST_SYNC_FIELDS;
 166        run->kvm_dirty_regs = KVM_SYNC_X86_REGS | KVM_SYNC_X86_SREGS;
 167        rv = _vcpu_run(vm, VCPU_ID);
 168        TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 169                    "Unexpected exit reason: %u (%s),\n",
 170                    run->exit_reason,
 171                    exit_reason_str(run->exit_reason));
 172        TEST_ASSERT(run->s.regs.regs.rbx == 0xBAD1DEA + 1,
 173                    "rbx sync regs value incorrect 0x%llx.",
 174                    run->s.regs.regs.rbx);
 175        TEST_ASSERT(run->s.regs.sregs.apic_base == 1 << 11,
 176                    "apic_base sync regs value incorrect 0x%llx.",
 177                    run->s.regs.sregs.apic_base);
 178
 179        vcpu_regs_get(vm, VCPU_ID, &regs);
 180        compare_regs(&regs, &run->s.regs.regs);
 181
 182        vcpu_sregs_get(vm, VCPU_ID, &sregs);
 183        compare_sregs(&sregs, &run->s.regs.sregs);
 184
 185        vcpu_events_get(vm, VCPU_ID, &events);
 186        compare_vcpu_events(&events, &run->s.regs.events);
 187
 188        /* Clear kvm_dirty_regs bits, verify new s.regs values are
 189         * overwritten with existing guest values.
 190         */
 191        run->kvm_valid_regs = TEST_SYNC_FIELDS;
 192        run->kvm_dirty_regs = 0;
 193        run->s.regs.regs.rbx = 0xDEADBEEF;
 194        rv = _vcpu_run(vm, VCPU_ID);
 195        TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 196                    "Unexpected exit reason: %u (%s),\n",
 197                    run->exit_reason,
 198                    exit_reason_str(run->exit_reason));
 199        TEST_ASSERT(run->s.regs.regs.rbx != 0xDEADBEEF,
 200                    "rbx sync regs value incorrect 0x%llx.",
 201                    run->s.regs.regs.rbx);
 202
 203        /* Clear kvm_valid_regs bits and kvm_dirty_bits.
 204         * Verify s.regs values are not overwritten with existing guest values
 205         * and that guest values are not overwritten with kvm_sync_regs values.
 206         */
 207        run->kvm_valid_regs = 0;
 208        run->kvm_dirty_regs = 0;
 209        run->s.regs.regs.rbx = 0xAAAA;
 210        regs.rbx = 0xBAC0;
 211        vcpu_regs_set(vm, VCPU_ID, &regs);
 212        rv = _vcpu_run(vm, VCPU_ID);
 213        TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 214                    "Unexpected exit reason: %u (%s),\n",
 215                    run->exit_reason,
 216                    exit_reason_str(run->exit_reason));
 217        TEST_ASSERT(run->s.regs.regs.rbx == 0xAAAA,
 218                    "rbx sync regs value incorrect 0x%llx.",
 219                    run->s.regs.regs.rbx);
 220        vcpu_regs_get(vm, VCPU_ID, &regs);
 221        TEST_ASSERT(regs.rbx == 0xBAC0 + 1,
 222                    "rbx guest value incorrect 0x%llx.",
 223                    regs.rbx);
 224
 225        /* Clear kvm_valid_regs bits. Verify s.regs values are not overwritten
 226         * with existing guest values but that guest values are overwritten
 227         * with kvm_sync_regs values.
 228         */
 229        run->kvm_valid_regs = 0;
 230        run->kvm_dirty_regs = TEST_SYNC_FIELDS;
 231        run->s.regs.regs.rbx = 0xBBBB;
 232        rv = _vcpu_run(vm, VCPU_ID);
 233        TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 234                    "Unexpected exit reason: %u (%s),\n",
 235                    run->exit_reason,
 236                    exit_reason_str(run->exit_reason));
 237        TEST_ASSERT(run->s.regs.regs.rbx == 0xBBBB,
 238                    "rbx sync regs value incorrect 0x%llx.",
 239                    run->s.regs.regs.rbx);
 240        vcpu_regs_get(vm, VCPU_ID, &regs);
 241        TEST_ASSERT(regs.rbx == 0xBBBB + 1,
 242                    "rbx guest value incorrect 0x%llx.",
 243                    regs.rbx);
 244
 245        kvm_vm_free(vm);
 246
 247        return 0;
 248}
 249