tools/testing/selftests/kvm/get-reg-list.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Check for KVM_GET_REG_LIST regressions.
   4  *
   5  * Copyright (C) 2020, Red Hat, Inc.
   6  *
   7  * When attempting to migrate from a host with an older kernel to a host
   8  * with a newer kernel we allow the newer kernel on the destination to
   9  * list new registers with get-reg-list. We assume they'll be unused, at
  10  * least until the guest reboots, and so they're relatively harmless.
  11  * However, if the destination host with the newer kernel is missing
  12  * registers which the source host with the older kernel has, then that's
  13  * a regression in get-reg-list. This test checks for that regression by
  14  * checking the current list against a blessed list. We should never have
  15  * missing registers, but if new ones appear then they can probably be
  16  * added to the blessed list. A completely new blessed list can be created
  17  * by running the test with the --list command line argument.
  18  *
  19  * The blessed list should be created from the oldest possible kernel.
  20  */
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <sys/types.h>
  26 #include <sys/wait.h>
  27 #include "kvm_util.h"
  28 #include "test_util.h"
  29 #include "processor.h"
  30
  31 static struct kvm_reg_list *reg_list;
  32 static __u64 *blessed_reg, blessed_n;
  33
  34 extern struct vcpu_reg_list *vcpu_configs[];
  35 extern int vcpu_configs_n;
  36
  37 #define for_each_reg(i)                                                         \
  38         for ((i) = 0; (i) < reg_list->n; ++(i))
  39
  40 #define for_each_reg_filtered(i)                                                \
  41         for_each_reg(i)                                                         \
  42                 if (!filter_reg(reg_list->reg[i]))
  43
  44 #define for_each_missing_reg(i)                                                 \
  45         for ((i) = 0; (i) < blessed_n; ++(i))                                   \
  46                 if (!find_reg(reg_list->reg, reg_list->n, blessed_reg[i]))      \
  47                         if (check_supported_reg(vcpu, blessed_reg[i]))
  48
  49 #define for_each_new_reg(i)                                                     \
  50         for_each_reg_filtered(i)                                                \
  51                 if (!find_reg(blessed_reg, blessed_n, reg_list->reg[i]))
  52
  53 #define for_each_present_blessed_reg(i)                                         \
  54         for_each_reg(i)                                                         \
  55                 if (find_reg(blessed_reg, blessed_n, reg_list->reg[i]))
  56
  57 static const char *config_name(struct vcpu_reg_list *c)
  58 {
  59         struct vcpu_reg_sublist *s;
  60         int len = 0;
  61
  62         if (c->name)
  63                 return c->name;
  64
  65         for_each_sublist(c, s)
  66                 len += strlen(s->name) + 1;
  67
  68         c->name = malloc(len);
  69
  70         len = 0;
  71         for_each_sublist(c, s) {
  72                 if (!strcmp(s->name, "base"))
  73                         continue;
  74                 if (len)
  75                         c->name[len++] = '+';
  76                 strcpy(c->name + len, s->name);
  77                 len += strlen(s->name);
  78         }
  79         c->name[len] = '\0';
  80
  81         return c->name;
  82 }
  83
  84 bool __weak check_supported_reg(struct kvm_vcpu *vcpu, __u64 reg)
  85 {
  86         return true;
  87 }
  88
  89 bool __weak filter_reg(__u64 reg)
  90 {
  91         return false;
  92 }
  93
  94 static bool find_reg(__u64 regs[], __u64 nr_regs, __u64 reg)
  95 {
  96         int i;
  97
  98         for (i = 0; i < nr_regs; ++i)
  99                 if (reg == regs[i])
 100                         return true;
 101         return false;
 102 }
 103
 104 void __weak print_reg(const char *prefix, __u64 id)
 105 {
 106         printf("\t0x%llx,\n", id);
 107 }
 108
 109 bool __weak check_reject_set(int err)
 110 {
 111         return true;
 112 }
 113
 114 void __weak finalize_vcpu(struct kvm_vcpu *vcpu, struct vcpu_reg_list *c)
 115 {
 116 }
 117
 118 #ifdef __aarch64__
 119 static void prepare_vcpu_init(struct vcpu_reg_list *c, struct kvm_vcpu_init *init)
 120 {
 121         struct vcpu_reg_sublist *s;
 122
 123         for_each_sublist(c, s)
 124                 if (s->capability)
 125                         init->features[s->feature / 32] |= 1 << (s->feature % 32);
 126 }
 127
 128 static struct kvm_vcpu *vcpu_config_get_vcpu(struct vcpu_reg_list *c, struct kvm_vm *vm)
 129 {
 130         struct kvm_vcpu_init init = { .target = -1, };
 131         struct kvm_vcpu *vcpu;
 132
 133         prepare_vcpu_init(c, &init);
 134         vcpu = __vm_vcpu_add(vm, 0);
 135         aarch64_vcpu_setup(vcpu, &init);
 136
 137         return vcpu;
 138 }
 139 #else
 140 static struct kvm_vcpu *vcpu_config_get_vcpu(struct vcpu_reg_list *c, struct kvm_vm *vm)
 141 {
 142         return __vm_vcpu_add(vm, 0);
 143 }
 144 #endif
 145
 146 static void check_supported(struct vcpu_reg_list *c)
 147 {
 148         struct vcpu_reg_sublist *s;
 149
 150         for_each_sublist(c, s) {
 151                 if (!s->capability)
 152                         continue;
 153
 154                 __TEST_REQUIRE(kvm_has_cap(s->capability),
 155                                "%s: %s not available, skipping tests\n",
 156                                config_name(c), s->name);
 157         }
 158 }
 159
 160 static bool print_list;
 161 static bool print_filtered;
 162
 163 static void run_test(struct vcpu_reg_list *c)
 164 {
 165         int new_regs = 0, missing_regs = 0, i, n;
 166         int failed_get = 0, failed_set = 0, failed_reject = 0;
 167         int skipped_set = 0;
 168         struct kvm_vcpu *vcpu;
 169         struct kvm_vm *vm;
 170         struct vcpu_reg_sublist *s;
 171
 172         check_supported(c);
 173
 174         vm = vm_create_barebones();
 175         vcpu = vcpu_config_get_vcpu(c, vm);
 176         finalize_vcpu(vcpu, c);
 177
 178         reg_list = vcpu_get_reg_list(vcpu);
 179
 180         if (print_list || print_filtered) {
 181                 putchar('\n');
 182                 for_each_reg(i) {
 183                         __u64 id = reg_list->reg[i];
 184                         if ((print_list && !filter_reg(id)) ||
 185                             (print_filtered && filter_reg(id)))
 186                                 print_reg(config_name(c), id);
 187                 }
 188                 putchar('\n');
 189                 return;
 190         }
 191
 192         for_each_sublist(c, s)
 193                 blessed_n += s->regs_n;
 194         blessed_reg = calloc(blessed_n, sizeof(__u64));
 195
 196         n = 0;
 197         for_each_sublist(c, s) {
 198                 for (i = 0; i < s->regs_n; ++i)
 199                         blessed_reg[n++] = s->regs[i];
 200         }
 201
 202         /*
 203          * We only test that we can get the register and then write back the
 204          * same value. Some registers may allow other values to be written
 205          * back, but others only allow some bits to be changed, and at least
 206          * for ID registers set will fail if the value does not exactly match
 207          * what was returned by get. If registers that allow other values to
 208          * be written need to have the other values tested, then we should
 209          * create a new set of tests for those in a new independent test
 210          * executable.
 211          *
 212          * Only do the get/set tests on present, blessed list registers,
 213          * since we don't know the capabilities of any new registers.
 214          */
 215         for_each_present_blessed_reg(i) {
 216                 uint8_t addr[2048 / 8];
 217                 struct kvm_one_reg reg = {
 218                         .id = reg_list->reg[i],
 219                         .addr = (__u64)&addr,
 220                 };
 221                 bool reject_reg = false, skip_reg = false;
 222                 int ret;
 223
 224                 ret = __vcpu_get_reg(vcpu, reg_list->reg[i], &addr);
 225                 if (ret) {
 226                         printf("%s: Failed to get ", config_name(c));
 227                         print_reg(config_name(c), reg.id);
 228                         putchar('\n');
 229                         ++failed_get;
 230                 }
 231
 232                 for_each_sublist(c, s) {
 233                         /* rejects_set registers are rejected for set operation */
 234                         if (s->rejects_set && find_reg(s->rejects_set, s->rejects_set_n, reg.id)) {
 235                                 reject_reg = true;
 236                                 ret = __vcpu_ioctl(vcpu, KVM_SET_ONE_REG, &reg);
 237                                 if (ret != -1 || !check_reject_set(errno)) {
 238                                         printf("%s: Failed to reject (ret=%d, errno=%d) ", config_name(c), ret, errno);
 239                                         print_reg(config_name(c), reg.id);
 240                                         putchar('\n');
 241                                         ++failed_reject;
 242                                 }
 243                                 break;
 244                         }
 245
 246                         /* skips_set registers are skipped for set operation */
 247                         if (s->skips_set && find_reg(s->skips_set, s->skips_set_n, reg.id)) {
 248                                 skip_reg = true;
 249                                 ++skipped_set;
 250                                 break;
 251                         }
 252                 }
 253
 254                 if (!reject_reg && !skip_reg) {
 255                         ret = __vcpu_ioctl(vcpu, KVM_SET_ONE_REG, &reg);
 256                         if (ret) {
 257                                 printf("%s: Failed to set ", config_name(c));
 258                                 print_reg(config_name(c), reg.id);
 259                                 putchar('\n');
 260                                 ++failed_set;
 261                         }
 262                 }
 263         }
 264
 265         for_each_new_reg(i)
 266                 ++new_regs;
 267
 268         for_each_missing_reg(i)
 269                 ++missing_regs;
 270
 271         if (new_regs || missing_regs) {
 272                 n = 0;
 273                 for_each_reg_filtered(i)
 274                         ++n;
 275
 276                 printf("%s: Number blessed registers: %5lld\n", config_name(c), blessed_n);
 277                 printf("%s: Number registers:         %5lld (includes %lld filtered registers)\n",
 278                        config_name(c), reg_list->n, reg_list->n - n);
 279         }
 280
 281         if (new_regs) {
 282                 printf("\n%s: There are %d new registers.\n"
 283                        "Consider adding them to the blessed reg "
 284                        "list with the following lines:\n\n", config_name(c), new_regs);
 285                 for_each_new_reg(i)
 286                         print_reg(config_name(c), reg_list->reg[i]);
 287                 putchar('\n');
 288         }
 289
 290         if (missing_regs) {
 291                 printf("\n%s: There are %d missing registers.\n"
 292                        "The following lines are missing registers:\n\n", config_name(c), missing_regs);
 293                 for_each_missing_reg(i)
 294                         print_reg(config_name(c), blessed_reg[i]);
 295                 putchar('\n');
 296         }
 297
 298         TEST_ASSERT(!missing_regs && !failed_get && !failed_set && !failed_reject,
 299                     "%s: There are %d missing registers; %d registers failed get; "
 300                     "%d registers failed set; %d registers failed reject; %d registers skipped set",
 301                     config_name(c), missing_regs, failed_get, failed_set, failed_reject, skipped_set);
 302
 303         pr_info("%s: PASS\n", config_name(c));
 304         blessed_n = 0;
 305         free(blessed_reg);
 306         free(reg_list);
 307         kvm_vm_free(vm);
 308 }
 309
 310 static void help(void)
 311 {
 312         struct vcpu_reg_list *c;
 313         int i;
 314
 315         printf(
 316         "\n"
 317         "usage: get-reg-list [--config=<selection>] [--list] [--list-filtered]\n\n"
 318         " --config=<selection>        Used to select a specific vcpu configuration for the test/listing\n"
 319         "                             '<selection>' may be\n");
 320
 321         for (i = 0; i < vcpu_configs_n; ++i) {
 322                 c = vcpu_configs[i];
 323                 printf(
 324         "                               '%s'\n", config_name(c));
 325         }
 326
 327         printf(
 328         "\n"
 329         " --list                      Print the register list rather than test it (requires --config)\n"
 330         " --list-filtered             Print registers that would normally be filtered out (requires --config)\n"
 331         "\n"
 332         );
 333 }
 334
 335 static struct vcpu_reg_list *parse_config(const char *config)
 336 {
 337         struct vcpu_reg_list *c = NULL;
 338         int i;
 339
 340         if (config[8] != '=')
 341                 help(), exit(1);
 342
 343         for (i = 0; i < vcpu_configs_n; ++i) {
 344                 c = vcpu_configs[i];
 345                 if (strcmp(config_name(c), &config[9]) == 0)
 346                         break;
 347         }
 348
 349         if (i == vcpu_configs_n)
 350                 help(), exit(1);
 351
 352         return c;
 353 }
 354
 355 int main(int ac, char **av)
 356 {
 357         struct vcpu_reg_list *c, *sel = NULL;
 358         int i, ret = 0;
 359         pid_t pid;
 360
 361         for (i = 1; i < ac; ++i) {
 362                 if (strncmp(av[i], "--config", 8) == 0)
 363                         sel = parse_config(av[i]);
 364                 else if (strcmp(av[i], "--list") == 0)
 365                         print_list = true;
 366                 else if (strcmp(av[i], "--list-filtered") == 0)
 367                         print_filtered = true;
 368                 else if (strcmp(av[i], "--help") == 0 || strcmp(av[1], "-h") == 0)
 369                         help(), exit(0);
 370                 else
 371                         help(), exit(1);
 372         }
 373
 374         if (print_list || print_filtered) {
 375                 /*
 376                  * We only want to print the register list of a single config.
 377                  */
 378                 if (!sel)
 379                         help(), exit(1);
 380         }
 381
 382         for (i = 0; i < vcpu_configs_n; ++i) {
 383                 c = vcpu_configs[i];
 384                 if (sel && c != sel)
 385                         continue;
 386
 387                 pid = fork();
 388
 389                 if (!pid) {
 390                         run_test(c);
 391                         exit(0);
 392                 } else {
 393                         int wstatus;
 394                         pid_t wpid = wait(&wstatus);
 395                         TEST_ASSERT(wpid == pid && WIFEXITED(wstatus), "wait: Unexpected return");
 396                         if (WEXITSTATUS(wstatus) && WEXITSTATUS(wstatus) != KSFT_SKIP)
 397                                 ret = KSFT_FAIL;
 398                 }
 399         }
 400
 401         return ret;
 402 }