hw/s390x/s390-skeys.c

   1 /*
   2  * s390 storage key device
   3  *
   4  * Copyright 2015 IBM Corp.
   5  * Author(s): Jason J. Herne <jjherne@linux.vnet.ibm.com>
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2 or (at
   8  * your option) any later version. See the COPYING file in the top-level
   9  * directory.
  10  */
  11
  12 #include "qemu/osdep.h"
  13 #include "qemu/units.h"
  14 #include "hw/boards.h"
  15 #include "hw/qdev-properties.h"
  16 #include "hw/s390x/storage-keys.h"
  17 #include "qapi/error.h"
  18 #include "qapi/qapi-commands-misc-target.h"
  19 #include "qapi/qmp/qdict.h"
  20 #include "qemu/error-report.h"
  21 #include "sysemu/memory_mapping.h"
  22 #include "exec/address-spaces.h"
  23 #include "sysemu/kvm.h"
  24 #include "migration/qemu-file-types.h"
  25 #include "migration/register.h"
  26 #include "trace.h"
  27
  28 #define S390_SKEYS_BUFFER_SIZE (128 * KiB)  /* Room for 128k storage keys */
  29 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
  30 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
  31 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
  32
  33 S390SKeysState *s390_get_skeys_device(void)
  34 {
  35     S390SKeysState *ss;
  36
  37     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
  38     assert(ss);
  39     return ss;
  40 }
  41
  42 void s390_skeys_init(void)
  43 {
  44     Object *obj;
  45
  46     if (kvm_enabled()) {
  47         obj = object_new(TYPE_KVM_S390_SKEYS);
  48     } else {
  49         obj = object_new(TYPE_QEMU_S390_SKEYS);
  50     }
  51     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
  52                               obj);
  53     object_unref(obj);
  54
  55     qdev_realize(DEVICE(obj), NULL, &error_fatal);
  56 }
  57
  58 int s390_skeys_get(S390SKeysState *ks, uint64_t start_gfn,
  59                    uint64_t count, uint8_t *keys)
  60 {
  61     S390SKeysClass *kc = S390_SKEYS_GET_CLASS(ks);
  62     int rc;
  63
  64     rc = kc->get_skeys(ks, start_gfn, count, keys);
  65     if (rc) {
  66         trace_s390_skeys_get_nonzero(rc);
  67     }
  68     return rc;
  69 }
  70
  71 int s390_skeys_set(S390SKeysState *ks, uint64_t start_gfn,
  72                    uint64_t count, uint8_t *keys)
  73 {
  74     S390SKeysClass *kc = S390_SKEYS_GET_CLASS(ks);
  75     int rc;
  76
  77     rc = kc->set_skeys(ks, start_gfn, count, keys);
  78     if (rc) {
  79         trace_s390_skeys_set_nonzero(rc);
  80     }
  81     return rc;
  82 }
  83
  84 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
  85                        uint64_t count, Error **errp)
  86 {
  87     uint64_t curpage = startgfn;
  88     uint64_t maxpage = curpage + count - 1;
  89
  90     for (; curpage <= maxpage; curpage++) {
  91         uint8_t acc = (*keys & 0xF0) >> 4;
  92         int fp =  (*keys & 0x08);
  93         int ref = (*keys & 0x04);
  94         int ch = (*keys & 0x02);
  95         int res = (*keys & 0x01);
  96
  97         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
  98                 " ch=%d, reserved=%d\n",
  99                 curpage, *keys, acc, fp, ref, ch, res);
 100         keys++;
 101     }
 102 }
 103
 104 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
 105 {
 106     S390SKeysState *ss = s390_get_skeys_device();
 107     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 108     uint64_t addr = qdict_get_int(qdict, "addr");
 109     uint8_t key;
 110     int r;
 111
 112     /* Quick check to see if guest is using storage keys*/
 113     if (!skeyclass->skeys_are_enabled(ss)) {
 114         monitor_printf(mon, "Error: This guest is not using storage keys\n");
 115         return;
 116     }
 117
 118     if (!address_space_access_valid(&address_space_memory,
 119                                     addr & TARGET_PAGE_MASK, TARGET_PAGE_SIZE,
 120                                     false, MEMTXATTRS_UNSPECIFIED)) {
 121         monitor_printf(mon, "Error: The given address is not valid\n");
 122         return;
 123     }
 124
 125     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
 126     if (r < 0) {
 127         monitor_printf(mon, "Error: %s\n", strerror(-r));
 128         return;
 129     }
 130
 131     monitor_printf(mon, "  key: 0x%X\n", key);
 132 }
 133
 134 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
 135 {
 136     const char *filename = qdict_get_str(qdict, "filename");
 137     Error *err = NULL;
 138
 139     qmp_dump_skeys(filename, &err);
 140     if (err) {
 141         error_report_err(err);
 142     }
 143 }
 144
 145 void qmp_dump_skeys(const char *filename, Error **errp)
 146 {
 147     S390SKeysState *ss = s390_get_skeys_device();
 148     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 149     GuestPhysBlockList guest_phys_blocks;
 150     GuestPhysBlock *block;
 151     uint64_t pages, gfn;
 152     Error *lerr = NULL;
 153     uint8_t *buf;
 154     int ret;
 155     int fd;
 156     FILE *f;
 157
 158     /* Quick check to see if guest is using storage keys*/
 159     if (!skeyclass->skeys_are_enabled(ss)) {
 160         error_setg(errp, "This guest is not using storage keys - "
 161                          "nothing to dump");
 162         return;
 163     }
 164
 165     fd = qemu_open_old(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 166     if (fd < 0) {
 167         error_setg_file_open(errp, errno, filename);
 168         return;
 169     }
 170     f = fdopen(fd, "wb");
 171     if (!f) {
 172         close(fd);
 173         error_setg_file_open(errp, errno, filename);
 174         return;
 175     }
 176
 177     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 178     if (!buf) {
 179         error_setg(errp, "Could not allocate memory");
 180         goto out;
 181     }
 182
 183     assert(bql_locked());
 184     guest_phys_blocks_init(&guest_phys_blocks);
 185     guest_phys_blocks_append(&guest_phys_blocks);
 186
 187     QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) {
 188         assert(QEMU_IS_ALIGNED(block->target_start, TARGET_PAGE_SIZE));
 189         assert(QEMU_IS_ALIGNED(block->target_end, TARGET_PAGE_SIZE));
 190
 191         gfn = block->target_start / TARGET_PAGE_SIZE;
 192         pages = (block->target_end - block->target_start) / TARGET_PAGE_SIZE;
 193
 194         while (pages) {
 195             const uint64_t cur_pages = MIN(pages, S390_SKEYS_BUFFER_SIZE);
 196
 197             ret = skeyclass->get_skeys(ss, gfn, cur_pages, buf);
 198             if (ret < 0) {
 199                 error_setg_errno(errp, -ret, "get_keys error");
 200                 goto out_free;
 201             }
 202
 203             /* write keys to stream */
 204             write_keys(f, buf, gfn, cur_pages, &lerr);
 205             if (lerr) {
 206                 goto out_free;
 207             }
 208
 209             gfn += cur_pages;
 210             pages -= cur_pages;
 211         }
 212     }
 213
 214 out_free:
 215     guest_phys_blocks_free(&guest_phys_blocks);
 216     error_propagate(errp, lerr);
 217     g_free(buf);
 218 out:
 219     fclose(f);
 220 }
 221
 222 static bool qemu_s390_skeys_are_enabled(S390SKeysState *ss)
 223 {
 224     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(ss);
 225
 226     /* Lockless check is sufficient. */
 227     return !!skeys->keydata;
 228 }
 229
 230 static bool qemu_s390_enable_skeys(S390SKeysState *ss)
 231 {
 232     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(ss);
 233     static gsize initialized;
 234
 235     if (likely(skeys->keydata)) {
 236         return true;
 237     }
 238
 239     /*
 240      * TODO: Modern Linux doesn't use storage keys unless running KVM guests
 241      *       that use storage keys. Therefore, we keep it simple for now.
 242      *
 243      * 1) We should initialize to "referenced+changed" for an initial
 244      *    over-indication. Let's avoid touching megabytes of data for now and
 245      *    assume that any sane user will issue a storage key instruction before
 246      *    actually relying on this data.
 247      * 2) Relying on ram_size and allocating a big array is ugly. We should
 248      *    allocate and manage storage key data per RAMBlock or optimally using
 249      *    some sparse data structure.
 250      * 3) We only ever have a single S390SKeysState, so relying on
 251      *    g_once_init_enter() is good enough.
 252      */
 253     if (g_once_init_enter(&initialized)) {
 254         MachineState *machine = MACHINE(qdev_get_machine());
 255
 256         skeys->key_count = machine->ram_size / TARGET_PAGE_SIZE;
 257         skeys->keydata = g_malloc0(skeys->key_count);
 258         g_once_init_leave(&initialized, 1);
 259     }
 260     return false;
 261 }
 262
 263 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
 264                               uint64_t count, uint8_t *keys)
 265 {
 266     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 267     int i;
 268
 269     /* Check for uint64 overflow and access beyond end of key data */
 270     if (unlikely(!skeydev->keydata || start_gfn + count > skeydev->key_count ||
 271                   start_gfn + count < count)) {
 272         error_report("Error: Setting storage keys for pages with unallocated "
 273                      "storage key memory: gfn=%" PRIx64 " count=%" PRId64,
 274                      start_gfn, count);
 275         return -EINVAL;
 276     }
 277
 278     for (i = 0; i < count; i++) {
 279         skeydev->keydata[start_gfn + i] = keys[i];
 280     }
 281     return 0;
 282 }
 283
 284 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
 285                                uint64_t count, uint8_t *keys)
 286 {
 287     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 288     int i;
 289
 290     /* Check for uint64 overflow and access beyond end of key data */
 291     if (unlikely(!skeydev->keydata || start_gfn + count > skeydev->key_count ||
 292                   start_gfn + count < count)) {
 293         error_report("Error: Getting storage keys for pages with unallocated "
 294                      "storage key memory: gfn=%" PRIx64 " count=%" PRId64,
 295                      start_gfn, count);
 296         return -EINVAL;
 297     }
 298
 299     for (i = 0; i < count; i++) {
 300         keys[i] = skeydev->keydata[start_gfn + i];
 301     }
 302     return 0;
 303 }
 304
 305 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
 306 {
 307     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
 308     DeviceClass *dc = DEVICE_CLASS(oc);
 309
 310     skeyclass->skeys_are_enabled = qemu_s390_skeys_are_enabled;
 311     skeyclass->enable_skeys = qemu_s390_enable_skeys;
 312     skeyclass->get_skeys = qemu_s390_skeys_get;
 313     skeyclass->set_skeys = qemu_s390_skeys_set;
 314
 315     /* Reason: Internal device (only one skeys device for the whole memory) */
 316     dc->user_creatable = false;
 317 }
 318
 319 static const TypeInfo qemu_s390_skeys_info = {
 320     .name          = TYPE_QEMU_S390_SKEYS,
 321     .parent        = TYPE_S390_SKEYS,
 322     .instance_size = sizeof(QEMUS390SKeysState),
 323     .class_init    = qemu_s390_skeys_class_init,
 324     .class_size    = sizeof(S390SKeysClass),
 325 };
 326
 327 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
 328 {
 329     S390SKeysState *ss = S390_SKEYS(opaque);
 330     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 331     GuestPhysBlockList guest_phys_blocks;
 332     GuestPhysBlock *block;
 333     uint64_t pages, gfn;
 334     int error = 0;
 335     uint8_t *buf;
 336
 337     if (!skeyclass->skeys_are_enabled(ss)) {
 338         goto end_stream;
 339     }
 340
 341     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 342     if (!buf) {
 343         error_report("storage key save could not allocate memory");
 344         goto end_stream;
 345     }
 346
 347     guest_phys_blocks_init(&guest_phys_blocks);
 348     guest_phys_blocks_append(&guest_phys_blocks);
 349
 350     /* Send each contiguous physical memory range separately. */
 351     QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) {
 352         assert(QEMU_IS_ALIGNED(block->target_start, TARGET_PAGE_SIZE));
 353         assert(QEMU_IS_ALIGNED(block->target_end, TARGET_PAGE_SIZE));
 354
 355         gfn = block->target_start / TARGET_PAGE_SIZE;
 356         pages = (block->target_end - block->target_start) / TARGET_PAGE_SIZE;
 357         qemu_put_be64(f, block->target_start | S390_SKEYS_SAVE_FLAG_SKEYS);
 358         qemu_put_be64(f, pages);
 359
 360         while (pages) {
 361             const uint64_t cur_pages = MIN(pages, S390_SKEYS_BUFFER_SIZE);
 362
 363             if (!error) {
 364                 error = skeyclass->get_skeys(ss, gfn, cur_pages, buf);
 365                 if (error) {
 366                     /*
 367                      * Create a valid stream with all 0x00 and indicate
 368                      * S390_SKEYS_SAVE_FLAG_ERROR to the destination.
 369                      */
 370                     error_report("S390_GET_KEYS error %d", error);
 371                     memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
 372                 }
 373             }
 374
 375             qemu_put_buffer(f, buf, cur_pages);
 376             gfn += cur_pages;
 377             pages -= cur_pages;
 378         }
 379
 380         if (error) {
 381             break;
 382         }
 383     }
 384
 385     guest_phys_blocks_free(&guest_phys_blocks);
 386     g_free(buf);
 387 end_stream:
 388     if (error) {
 389         qemu_put_be64(f, S390_SKEYS_SAVE_FLAG_ERROR);
 390     } else {
 391         qemu_put_be64(f, S390_SKEYS_SAVE_FLAG_EOS);
 392     }
 393 }
 394
 395 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
 396 {
 397     S390SKeysState *ss = S390_SKEYS(opaque);
 398     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 399     int ret = 0;
 400
 401     /*
 402      * Make sure to lazy-enable if required to be done explicitly. No need to
 403      * flush any TLB as the VM is not running yet.
 404      */
 405     if (skeyclass->enable_skeys) {
 406         skeyclass->enable_skeys(ss);
 407     }
 408
 409     while (!ret) {
 410         ram_addr_t addr;
 411         int flags;
 412
 413         addr = qemu_get_be64(f);
 414         flags = addr & ~TARGET_PAGE_MASK;
 415         addr &= TARGET_PAGE_MASK;
 416
 417         switch (flags) {
 418         case S390_SKEYS_SAVE_FLAG_SKEYS: {
 419             const uint64_t total_count = qemu_get_be64(f);
 420             uint64_t handled_count = 0, cur_count;
 421             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
 422             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 423
 424             if (!buf) {
 425                 error_report("storage key load could not allocate memory");
 426                 ret = -ENOMEM;
 427                 break;
 428             }
 429
 430             while (handled_count < total_count) {
 431                 cur_count = MIN(total_count - handled_count,
 432                                 S390_SKEYS_BUFFER_SIZE);
 433                 qemu_get_buffer(f, buf, cur_count);
 434
 435                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
 436                 if (ret < 0) {
 437                     error_report("S390_SET_KEYS error %d", ret);
 438                     break;
 439                 }
 440                 handled_count += cur_count;
 441                 cur_gfn += cur_count;
 442             }
 443             g_free(buf);
 444             break;
 445         }
 446         case S390_SKEYS_SAVE_FLAG_ERROR: {
 447             error_report("Storage key data is incomplete");
 448             ret = -EINVAL;
 449             break;
 450         }
 451         case S390_SKEYS_SAVE_FLAG_EOS:
 452             /* normal exit */
 453             return 0;
 454         default:
 455             error_report("Unexpected storage key flag data: %#x", flags);
 456             ret = -EINVAL;
 457         }
 458     }
 459
 460     return ret;
 461 }
 462
 463 static SaveVMHandlers savevm_s390_storage_keys = {
 464     .save_state = s390_storage_keys_save,
 465     .load_state = s390_storage_keys_load,
 466 };
 467
 468 static void s390_skeys_realize(DeviceState *dev, Error **errp)
 469 {
 470     S390SKeysState *ss = S390_SKEYS(dev);
 471
 472     if (ss->migration_enabled) {
 473         register_savevm_live(TYPE_S390_SKEYS, 0, 1,
 474                              &savevm_s390_storage_keys, ss);
 475     }
 476 }
 477
 478 static Property s390_skeys_props[] = {
 479     DEFINE_PROP_BOOL("migration-enabled", S390SKeysState, migration_enabled, true),
 480     DEFINE_PROP_END_OF_LIST(),
 481 };
 482
 483 static void s390_skeys_class_init(ObjectClass *oc, void *data)
 484 {
 485     DeviceClass *dc = DEVICE_CLASS(oc);
 486
 487     dc->hotpluggable = false;
 488     dc->realize = s390_skeys_realize;
 489     device_class_set_props(dc, s390_skeys_props);
 490     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 491 }
 492
 493 static const TypeInfo s390_skeys_info = {
 494     .name          = TYPE_S390_SKEYS,
 495     .parent        = TYPE_DEVICE,
 496     .instance_size = sizeof(S390SKeysState),
 497     .class_init    = s390_skeys_class_init,
 498     .class_size    = sizeof(S390SKeysClass),
 499     .abstract = true,
 500 };
 501
 502 static void qemu_s390_skeys_register_types(void)
 503 {
 504     type_register_static(&s390_skeys_info);
 505     type_register_static(&qemu_s390_skeys_info);
 506 }
 507
 508 type_init(qemu_s390_skeys_register_types)