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/s390x/storage-keys.h"
  16 #include "qapi/error.h"
  17 #include "qapi/qapi-commands-misc-target.h"
  18 #include "qapi/qmp/qdict.h"
  19 #include "qemu/error-report.h"
  20 #include "sysemu/kvm.h"
  21 #include "migration/qemu-file-types.h"
  22 #include "migration/register.h"
  23
  24 #define S390_SKEYS_BUFFER_SIZE (128 * KiB)  /* Room for 128k storage keys */
  25 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
  26 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
  27 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
  28
  29 S390SKeysState *s390_get_skeys_device(void)
  30 {
  31     S390SKeysState *ss;
  32
  33     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
  34     assert(ss);
  35     return ss;
  36 }
  37
  38 void s390_skeys_init(void)
  39 {
  40     Object *obj;
  41
  42     if (kvm_enabled()) {
  43         obj = object_new(TYPE_KVM_S390_SKEYS);
  44     } else {
  45         obj = object_new(TYPE_QEMU_S390_SKEYS);
  46     }
  47     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
  48                               obj);
  49     object_unref(obj);
  50
  51     qdev_realize(DEVICE(obj), NULL, &error_fatal);
  52 }
  53
  54 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
  55                        uint64_t count, Error **errp)
  56 {
  57     uint64_t curpage = startgfn;
  58     uint64_t maxpage = curpage + count - 1;
  59
  60     for (; curpage <= maxpage; curpage++) {
  61         uint8_t acc = (*keys & 0xF0) >> 4;
  62         int fp =  (*keys & 0x08);
  63         int ref = (*keys & 0x04);
  64         int ch = (*keys & 0x02);
  65         int res = (*keys & 0x01);
  66
  67         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
  68                 " ch=%d, reserved=%d\n",
  69                 curpage, *keys, acc, fp, ref, ch, res);
  70         keys++;
  71     }
  72 }
  73
  74 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
  75 {
  76     S390SKeysState *ss = s390_get_skeys_device();
  77     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
  78     uint64_t addr = qdict_get_int(qdict, "addr");
  79     uint8_t key;
  80     int r;
  81
  82     /* Quick check to see if guest is using storage keys*/
  83     if (!skeyclass->skeys_enabled(ss)) {
  84         monitor_printf(mon, "Error: This guest is not using storage keys\n");
  85         return;
  86     }
  87
  88     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
  89     if (r < 0) {
  90         monitor_printf(mon, "Error: %s\n", strerror(-r));
  91         return;
  92     }
  93
  94     monitor_printf(mon, "  key: 0x%X\n", key);
  95 }
  96
  97 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
  98 {
  99     const char *filename = qdict_get_str(qdict, "filename");
 100     Error *err = NULL;
 101
 102     qmp_dump_skeys(filename, &err);
 103     if (err) {
 104         error_report_err(err);
 105     }
 106 }
 107
 108 void qmp_dump_skeys(const char *filename, Error **errp)
 109 {
 110     S390SKeysState *ss = s390_get_skeys_device();
 111     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 112     const uint64_t total_count = ram_size / TARGET_PAGE_SIZE;
 113     uint64_t handled_count = 0, cur_count;
 114     Error *lerr = NULL;
 115     vaddr cur_gfn = 0;
 116     uint8_t *buf;
 117     int ret;
 118     int fd;
 119     FILE *f;
 120
 121     /* Quick check to see if guest is using storage keys*/
 122     if (!skeyclass->skeys_enabled(ss)) {
 123         error_setg(errp, "This guest is not using storage keys - "
 124                          "nothing to dump");
 125         return;
 126     }
 127
 128     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 129     if (fd < 0) {
 130         error_setg_file_open(errp, errno, filename);
 131         return;
 132     }
 133     f = fdopen(fd, "wb");
 134     if (!f) {
 135         close(fd);
 136         error_setg_file_open(errp, errno, filename);
 137         return;
 138     }
 139
 140     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 141     if (!buf) {
 142         error_setg(errp, "Could not allocate memory");
 143         goto out;
 144     }
 145
 146     /* we'll only dump initial memory for now */
 147     while (handled_count < total_count) {
 148         /* Calculate how many keys to ask for & handle overflow case */
 149         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
 150
 151         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
 152         if (ret < 0) {
 153             error_setg(errp, "get_keys error %d", ret);
 154             goto out_free;
 155         }
 156
 157         /* write keys to stream */
 158         write_keys(f, buf, cur_gfn, cur_count, &lerr);
 159         if (lerr) {
 160             goto out_free;
 161         }
 162
 163         cur_gfn += cur_count;
 164         handled_count += cur_count;
 165     }
 166
 167 out_free:
 168     error_propagate(errp, lerr);
 169     g_free(buf);
 170 out:
 171     fclose(f);
 172 }
 173
 174 static void qemu_s390_skeys_init(Object *obj)
 175 {
 176     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
 177     MachineState *machine = MACHINE(qdev_get_machine());
 178
 179     skeys->key_count = machine->ram_size / TARGET_PAGE_SIZE;
 180     skeys->keydata = g_malloc0(skeys->key_count);
 181 }
 182
 183 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
 184 {
 185     return 1;
 186 }
 187
 188 /*
 189  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
 190  * will have to make sure that the given gfn belongs to a memory region and not
 191  * a memory hole.
 192  */
 193 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
 194                               uint64_t count, uint8_t *keys)
 195 {
 196     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 197     int i;
 198
 199     /* Check for uint64 overflow and access beyond end of key data */
 200     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 201         error_report("Error: Setting storage keys for page beyond the end "
 202                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 203                      start_gfn, count);
 204         return -EINVAL;
 205     }
 206
 207     for (i = 0; i < count; i++) {
 208         skeydev->keydata[start_gfn + i] = keys[i];
 209     }
 210     return 0;
 211 }
 212
 213 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
 214                                uint64_t count, uint8_t *keys)
 215 {
 216     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 217     int i;
 218
 219     /* Check for uint64 overflow and access beyond end of key data */
 220     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 221         error_report("Error: Getting storage keys for page beyond the end "
 222                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 223                      start_gfn, count);
 224         return -EINVAL;
 225     }
 226
 227     for (i = 0; i < count; i++) {
 228         keys[i] = skeydev->keydata[start_gfn + i];
 229     }
 230     return 0;
 231 }
 232
 233 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
 234 {
 235     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
 236     DeviceClass *dc = DEVICE_CLASS(oc);
 237
 238     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
 239     skeyclass->get_skeys = qemu_s390_skeys_get;
 240     skeyclass->set_skeys = qemu_s390_skeys_set;
 241
 242     /* Reason: Internal device (only one skeys device for the whole memory) */
 243     dc->user_creatable = false;
 244 }
 245
 246 static const TypeInfo qemu_s390_skeys_info = {
 247     .name          = TYPE_QEMU_S390_SKEYS,
 248     .parent        = TYPE_S390_SKEYS,
 249     .instance_init = qemu_s390_skeys_init,
 250     .instance_size = sizeof(QEMUS390SKeysState),
 251     .class_init    = qemu_s390_skeys_class_init,
 252     .class_size    = sizeof(S390SKeysClass),
 253 };
 254
 255 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
 256 {
 257     S390SKeysState *ss = S390_SKEYS(opaque);
 258     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 259     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
 260     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
 261     vaddr cur_gfn = 0;
 262     int error = 0;
 263     uint8_t *buf;
 264
 265     if (!skeyclass->skeys_enabled(ss)) {
 266         goto end_stream;
 267     }
 268
 269     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 270     if (!buf) {
 271         error_report("storage key save could not allocate memory");
 272         goto end_stream;
 273     }
 274
 275     /* We only support initial memory. Standby memory is not handled yet. */
 276     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
 277     qemu_put_be64(f, pages_left);
 278
 279     while (pages_left) {
 280         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
 281
 282         if (!error) {
 283             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
 284             if (error) {
 285                 /*
 286                  * If error: we want to fill the stream with valid data instead
 287                  * of stopping early so we pad the stream with 0x00 values and
 288                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
 289                  * reading side.
 290                  */
 291                 error_report("S390_GET_KEYS error %d", error);
 292                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
 293                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
 294             }
 295         }
 296
 297         qemu_put_buffer(f, buf, read_count);
 298         cur_gfn += read_count;
 299         pages_left -= read_count;
 300     }
 301
 302     g_free(buf);
 303 end_stream:
 304     qemu_put_be64(f, eos);
 305 }
 306
 307 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
 308 {
 309     S390SKeysState *ss = S390_SKEYS(opaque);
 310     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 311     int ret = 0;
 312
 313     while (!ret) {
 314         ram_addr_t addr;
 315         int flags;
 316
 317         addr = qemu_get_be64(f);
 318         flags = addr & ~TARGET_PAGE_MASK;
 319         addr &= TARGET_PAGE_MASK;
 320
 321         switch (flags) {
 322         case S390_SKEYS_SAVE_FLAG_SKEYS: {
 323             const uint64_t total_count = qemu_get_be64(f);
 324             uint64_t handled_count = 0, cur_count;
 325             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
 326             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 327
 328             if (!buf) {
 329                 error_report("storage key load could not allocate memory");
 330                 ret = -ENOMEM;
 331                 break;
 332             }
 333
 334             while (handled_count < total_count) {
 335                 cur_count = MIN(total_count - handled_count,
 336                                 S390_SKEYS_BUFFER_SIZE);
 337                 qemu_get_buffer(f, buf, cur_count);
 338
 339                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
 340                 if (ret < 0) {
 341                     error_report("S390_SET_KEYS error %d", ret);
 342                     break;
 343                 }
 344                 handled_count += cur_count;
 345                 cur_gfn += cur_count;
 346             }
 347             g_free(buf);
 348             break;
 349         }
 350         case S390_SKEYS_SAVE_FLAG_ERROR: {
 351             error_report("Storage key data is incomplete");
 352             ret = -EINVAL;
 353             break;
 354         }
 355         case S390_SKEYS_SAVE_FLAG_EOS:
 356             /* normal exit */
 357             return 0;
 358         default:
 359             error_report("Unexpected storage key flag data: %#x", flags);
 360             ret = -EINVAL;
 361         }
 362     }
 363
 364     return ret;
 365 }
 366
 367 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
 368 {
 369     S390SKeysState *ss = S390_SKEYS(obj);
 370
 371     return ss->migration_enabled;
 372 }
 373
 374 static SaveVMHandlers savevm_s390_storage_keys = {
 375     .save_state = s390_storage_keys_save,
 376     .load_state = s390_storage_keys_load,
 377 };
 378
 379 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
 380                                             Error **errp)
 381 {
 382     S390SKeysState *ss = S390_SKEYS(obj);
 383
 384     /* Prevent double registration of savevm handler */
 385     if (ss->migration_enabled == value) {
 386         return;
 387     }
 388
 389     ss->migration_enabled = value;
 390
 391     if (ss->migration_enabled) {
 392         register_savevm_live(TYPE_S390_SKEYS, 0, 1,
 393                              &savevm_s390_storage_keys, ss);
 394     } else {
 395         unregister_savevm(VMSTATE_IF(ss), TYPE_S390_SKEYS, ss);
 396     }
 397 }
 398
 399 static void s390_skeys_instance_init(Object *obj)
 400 {
 401     object_property_add_bool(obj, "migration-enabled",
 402                              s390_skeys_get_migration_enabled,
 403                              s390_skeys_set_migration_enabled);
 404     object_property_set_bool(obj, "migration-enabled", true, NULL);
 405 }
 406
 407 static void s390_skeys_class_init(ObjectClass *oc, void *data)
 408 {
 409     DeviceClass *dc = DEVICE_CLASS(oc);
 410
 411     dc->hotpluggable = false;
 412     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 413 }
 414
 415 static const TypeInfo s390_skeys_info = {
 416     .name          = TYPE_S390_SKEYS,
 417     .parent        = TYPE_DEVICE,
 418     .instance_init = s390_skeys_instance_init,
 419     .instance_size = sizeof(S390SKeysState),
 420     .class_init    = s390_skeys_class_init,
 421     .class_size    = sizeof(S390SKeysClass),
 422     .abstract = true,
 423 };
 424
 425 static void qemu_s390_skeys_register_types(void)
 426 {
 427     type_register_static(&s390_skeys_info);
 428     type_register_static(&qemu_s390_skeys_info);
 429 }
 430
 431 type_init(qemu_s390_skeys_register_types)