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     MachineState *ms = MACHINE(qdev_get_machine());
 113     const uint64_t total_count = ms->ram_size / TARGET_PAGE_SIZE;
 114     uint64_t handled_count = 0, cur_count;
 115     Error *lerr = NULL;
 116     vaddr cur_gfn = 0;
 117     uint8_t *buf;
 118     int ret;
 119     int fd;
 120     FILE *f;
 121
 122     /* Quick check to see if guest is using storage keys*/
 123     if (!skeyclass->skeys_enabled(ss)) {
 124         error_setg(errp, "This guest is not using storage keys - "
 125                          "nothing to dump");
 126         return;
 127     }
 128
 129     fd = qemu_open_old(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 130     if (fd < 0) {
 131         error_setg_file_open(errp, errno, filename);
 132         return;
 133     }
 134     f = fdopen(fd, "wb");
 135     if (!f) {
 136         close(fd);
 137         error_setg_file_open(errp, errno, filename);
 138         return;
 139     }
 140
 141     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 142     if (!buf) {
 143         error_setg(errp, "Could not allocate memory");
 144         goto out;
 145     }
 146
 147     /* we'll only dump initial memory for now */
 148     while (handled_count < total_count) {
 149         /* Calculate how many keys to ask for & handle overflow case */
 150         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
 151
 152         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
 153         if (ret < 0) {
 154             error_setg(errp, "get_keys error %d", ret);
 155             goto out_free;
 156         }
 157
 158         /* write keys to stream */
 159         write_keys(f, buf, cur_gfn, cur_count, &lerr);
 160         if (lerr) {
 161             goto out_free;
 162         }
 163
 164         cur_gfn += cur_count;
 165         handled_count += cur_count;
 166     }
 167
 168 out_free:
 169     error_propagate(errp, lerr);
 170     g_free(buf);
 171 out:
 172     fclose(f);
 173 }
 174
 175 static void qemu_s390_skeys_init(Object *obj)
 176 {
 177     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
 178     MachineState *machine = MACHINE(qdev_get_machine());
 179
 180     skeys->key_count = machine->ram_size / TARGET_PAGE_SIZE;
 181     skeys->keydata = g_malloc0(skeys->key_count);
 182 }
 183
 184 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
 185 {
 186     return 1;
 187 }
 188
 189 /*
 190  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
 191  * will have to make sure that the given gfn belongs to a memory region and not
 192  * a memory hole.
 193  */
 194 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
 195                               uint64_t count, uint8_t *keys)
 196 {
 197     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 198     int i;
 199
 200     /* Check for uint64 overflow and access beyond end of key data */
 201     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 202         error_report("Error: Setting storage keys for page beyond the end "
 203                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 204                      start_gfn, count);
 205         return -EINVAL;
 206     }
 207
 208     for (i = 0; i < count; i++) {
 209         skeydev->keydata[start_gfn + i] = keys[i];
 210     }
 211     return 0;
 212 }
 213
 214 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
 215                                uint64_t count, uint8_t *keys)
 216 {
 217     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 218     int i;
 219
 220     /* Check for uint64 overflow and access beyond end of key data */
 221     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 222         error_report("Error: Getting storage keys for page beyond the end "
 223                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 224                      start_gfn, count);
 225         return -EINVAL;
 226     }
 227
 228     for (i = 0; i < count; i++) {
 229         keys[i] = skeydev->keydata[start_gfn + i];
 230     }
 231     return 0;
 232 }
 233
 234 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
 235 {
 236     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
 237     DeviceClass *dc = DEVICE_CLASS(oc);
 238
 239     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
 240     skeyclass->get_skeys = qemu_s390_skeys_get;
 241     skeyclass->set_skeys = qemu_s390_skeys_set;
 242
 243     /* Reason: Internal device (only one skeys device for the whole memory) */
 244     dc->user_creatable = false;
 245 }
 246
 247 static const TypeInfo qemu_s390_skeys_info = {
 248     .name          = TYPE_QEMU_S390_SKEYS,
 249     .parent        = TYPE_S390_SKEYS,
 250     .instance_init = qemu_s390_skeys_init,
 251     .instance_size = sizeof(QEMUS390SKeysState),
 252     .class_init    = qemu_s390_skeys_class_init,
 253     .class_size    = sizeof(S390SKeysClass),
 254 };
 255
 256 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
 257 {
 258     S390SKeysState *ss = S390_SKEYS(opaque);
 259     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 260     MachineState *ms = MACHINE(qdev_get_machine());
 261     uint64_t pages_left = ms->ram_size / TARGET_PAGE_SIZE;
 262     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
 263     vaddr cur_gfn = 0;
 264     int error = 0;
 265     uint8_t *buf;
 266
 267     if (!skeyclass->skeys_enabled(ss)) {
 268         goto end_stream;
 269     }
 270
 271     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 272     if (!buf) {
 273         error_report("storage key save could not allocate memory");
 274         goto end_stream;
 275     }
 276
 277     /* We only support initial memory. Standby memory is not handled yet. */
 278     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
 279     qemu_put_be64(f, pages_left);
 280
 281     while (pages_left) {
 282         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
 283
 284         if (!error) {
 285             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
 286             if (error) {
 287                 /*
 288                  * If error: we want to fill the stream with valid data instead
 289                  * of stopping early so we pad the stream with 0x00 values and
 290                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
 291                  * reading side.
 292                  */
 293                 error_report("S390_GET_KEYS error %d", error);
 294                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
 295                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
 296             }
 297         }
 298
 299         qemu_put_buffer(f, buf, read_count);
 300         cur_gfn += read_count;
 301         pages_left -= read_count;
 302     }
 303
 304     g_free(buf);
 305 end_stream:
 306     qemu_put_be64(f, eos);
 307 }
 308
 309 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
 310 {
 311     S390SKeysState *ss = S390_SKEYS(opaque);
 312     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 313     int ret = 0;
 314
 315     while (!ret) {
 316         ram_addr_t addr;
 317         int flags;
 318
 319         addr = qemu_get_be64(f);
 320         flags = addr & ~TARGET_PAGE_MASK;
 321         addr &= TARGET_PAGE_MASK;
 322
 323         switch (flags) {
 324         case S390_SKEYS_SAVE_FLAG_SKEYS: {
 325             const uint64_t total_count = qemu_get_be64(f);
 326             uint64_t handled_count = 0, cur_count;
 327             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
 328             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 329
 330             if (!buf) {
 331                 error_report("storage key load could not allocate memory");
 332                 ret = -ENOMEM;
 333                 break;
 334             }
 335
 336             while (handled_count < total_count) {
 337                 cur_count = MIN(total_count - handled_count,
 338                                 S390_SKEYS_BUFFER_SIZE);
 339                 qemu_get_buffer(f, buf, cur_count);
 340
 341                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
 342                 if (ret < 0) {
 343                     error_report("S390_SET_KEYS error %d", ret);
 344                     break;
 345                 }
 346                 handled_count += cur_count;
 347                 cur_gfn += cur_count;
 348             }
 349             g_free(buf);
 350             break;
 351         }
 352         case S390_SKEYS_SAVE_FLAG_ERROR: {
 353             error_report("Storage key data is incomplete");
 354             ret = -EINVAL;
 355             break;
 356         }
 357         case S390_SKEYS_SAVE_FLAG_EOS:
 358             /* normal exit */
 359             return 0;
 360         default:
 361             error_report("Unexpected storage key flag data: %#x", flags);
 362             ret = -EINVAL;
 363         }
 364     }
 365
 366     return ret;
 367 }
 368
 369 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
 370 {
 371     S390SKeysState *ss = S390_SKEYS(obj);
 372
 373     return ss->migration_enabled;
 374 }
 375
 376 static SaveVMHandlers savevm_s390_storage_keys = {
 377     .save_state = s390_storage_keys_save,
 378     .load_state = s390_storage_keys_load,
 379 };
 380
 381 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
 382                                             Error **errp)
 383 {
 384     S390SKeysState *ss = S390_SKEYS(obj);
 385
 386     /* Prevent double registration of savevm handler */
 387     if (ss->migration_enabled == value) {
 388         return;
 389     }
 390
 391     ss->migration_enabled = value;
 392
 393     if (ss->migration_enabled) {
 394         register_savevm_live(TYPE_S390_SKEYS, 0, 1,
 395                              &savevm_s390_storage_keys, ss);
 396     } else {
 397         unregister_savevm(VMSTATE_IF(ss), TYPE_S390_SKEYS, ss);
 398     }
 399 }
 400
 401 static void s390_skeys_instance_init(Object *obj)
 402 {
 403     object_property_add_bool(obj, "migration-enabled",
 404                              s390_skeys_get_migration_enabled,
 405                              s390_skeys_set_migration_enabled);
 406     object_property_set_bool(obj, "migration-enabled", true, NULL);
 407 }
 408
 409 static void s390_skeys_class_init(ObjectClass *oc, void *data)
 410 {
 411     DeviceClass *dc = DEVICE_CLASS(oc);
 412
 413     dc->hotpluggable = false;
 414     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 415 }
 416
 417 static const TypeInfo s390_skeys_info = {
 418     .name          = TYPE_S390_SKEYS,
 419     .parent        = TYPE_DEVICE,
 420     .instance_init = s390_skeys_instance_init,
 421     .instance_size = sizeof(S390SKeysState),
 422     .class_init    = s390_skeys_class_init,
 423     .class_size    = sizeof(S390SKeysClass),
 424     .abstract = true,
 425 };
 426
 427 static void qemu_s390_skeys_register_types(void)
 428 {
 429     type_register_static(&s390_skeys_info);
 430     type_register_static(&qemu_s390_skeys_info);
 431 }
 432
 433 type_init(qemu_s390_skeys_register_types)