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 "hw/boards.h"
  14 #include "qmp-commands.h"
  15 #include "hw/s390x/storage-keys.h"
  16 #include "qapi/error.h"
  17 #include "qapi/qmp/qdict.h"
  18 #include "qemu/error-report.h"
  19 #include "sysemu/kvm.h"
  20 #include "migration/register.h"
  21
  22 #define S390_SKEYS_BUFFER_SIZE 131072  /* Room for 128k storage keys */
  23 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
  24 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
  25 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
  26
  27 S390SKeysState *s390_get_skeys_device(void)
  28 {
  29     S390SKeysState *ss;
  30
  31     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
  32     assert(ss);
  33     return ss;
  34 }
  35
  36 void s390_skeys_init(void)
  37 {
  38     Object *obj;
  39
  40     if (kvm_enabled()) {
  41         obj = object_new(TYPE_KVM_S390_SKEYS);
  42     } else {
  43         obj = object_new(TYPE_QEMU_S390_SKEYS);
  44     }
  45     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
  46                               obj, NULL);
  47     object_unref(obj);
  48
  49     qdev_init_nofail(DEVICE(obj));
  50 }
  51
  52 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
  53                        uint64_t count, Error **errp)
  54 {
  55     uint64_t curpage = startgfn;
  56     uint64_t maxpage = curpage + count - 1;
  57
  58     for (; curpage <= maxpage; curpage++) {
  59         uint8_t acc = (*keys & 0xF0) >> 4;
  60         int fp =  (*keys & 0x08);
  61         int ref = (*keys & 0x04);
  62         int ch = (*keys & 0x02);
  63         int res = (*keys & 0x01);
  64
  65         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
  66                 " ch=%d, reserved=%d\n",
  67                 curpage, *keys, acc, fp, ref, ch, res);
  68         keys++;
  69     }
  70 }
  71
  72 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
  73 {
  74     S390SKeysState *ss = s390_get_skeys_device();
  75     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
  76     uint64_t addr = qdict_get_int(qdict, "addr");
  77     uint8_t key;
  78     int r;
  79
  80     /* Quick check to see if guest is using storage keys*/
  81     if (!skeyclass->skeys_enabled(ss)) {
  82         monitor_printf(mon, "Error: This guest is not using storage keys\n");
  83         return;
  84     }
  85
  86     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
  87     if (r < 0) {
  88         monitor_printf(mon, "Error: %s\n", strerror(-r));
  89         return;
  90     }
  91
  92     monitor_printf(mon, "  key: 0x%X\n", key);
  93 }
  94
  95 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
  96 {
  97     const char *filename = qdict_get_str(qdict, "filename");
  98     Error *err = NULL;
  99
 100     qmp_dump_skeys(filename, &err);
 101     if (err) {
 102         error_report_err(err);
 103     }
 104 }
 105
 106 void qmp_dump_skeys(const char *filename, Error **errp)
 107 {
 108     S390SKeysState *ss = s390_get_skeys_device();
 109     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 110     const uint64_t total_count = ram_size / TARGET_PAGE_SIZE;
 111     uint64_t handled_count = 0, cur_count;
 112     Error *lerr = NULL;
 113     vaddr cur_gfn = 0;
 114     uint8_t *buf;
 115     int ret;
 116     int fd;
 117     FILE *f;
 118
 119     /* Quick check to see if guest is using storage keys*/
 120     if (!skeyclass->skeys_enabled(ss)) {
 121         error_setg(errp, "This guest is not using storage keys - "
 122                          "nothing to dump");
 123         return;
 124     }
 125
 126     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 127     if (fd < 0) {
 128         error_setg_file_open(errp, errno, filename);
 129         return;
 130     }
 131     f = fdopen(fd, "wb");
 132     if (!f) {
 133         close(fd);
 134         error_setg_file_open(errp, errno, filename);
 135         return;
 136     }
 137
 138     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 139     if (!buf) {
 140         error_setg(errp, "Could not allocate memory");
 141         goto out;
 142     }
 143
 144     /* we'll only dump initial memory for now */
 145     while (handled_count < total_count) {
 146         /* Calculate how many keys to ask for & handle overflow case */
 147         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
 148
 149         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
 150         if (ret < 0) {
 151             error_setg(errp, "get_keys error %d", ret);
 152             goto out_free;
 153         }
 154
 155         /* write keys to stream */
 156         write_keys(f, buf, cur_gfn, cur_count, &lerr);
 157         if (lerr) {
 158             goto out_free;
 159         }
 160
 161         cur_gfn += cur_count;
 162         handled_count += cur_count;
 163     }
 164
 165 out_free:
 166     error_propagate(errp, lerr);
 167     g_free(buf);
 168 out:
 169     fclose(f);
 170 }
 171
 172 static void qemu_s390_skeys_init(Object *obj)
 173 {
 174     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
 175     MachineState *machine = MACHINE(qdev_get_machine());
 176
 177     skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
 178     skeys->keydata = g_malloc0(skeys->key_count);
 179 }
 180
 181 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
 182 {
 183     return 1;
 184 }
 185
 186 /*
 187  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
 188  * will have to make sure that the given gfn belongs to a memory region and not
 189  * a memory hole.
 190  */
 191 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
 192                               uint64_t count, uint8_t *keys)
 193 {
 194     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 195     int i;
 196
 197     /* Check for uint64 overflow and access beyond end of key data */
 198     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 199         error_report("Error: Setting storage keys for page beyond the end "
 200                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 201                      start_gfn, count);
 202         return -EINVAL;
 203     }
 204
 205     for (i = 0; i < count; i++) {
 206         skeydev->keydata[start_gfn + i] = keys[i];
 207     }
 208     return 0;
 209 }
 210
 211 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
 212                                uint64_t count, uint8_t *keys)
 213 {
 214     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
 215     int i;
 216
 217     /* Check for uint64 overflow and access beyond end of key data */
 218     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
 219         error_report("Error: Getting storage keys for page beyond the end "
 220                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
 221                      start_gfn, count);
 222         return -EINVAL;
 223     }
 224
 225     for (i = 0; i < count; i++) {
 226         keys[i] = skeydev->keydata[start_gfn + i];
 227     }
 228     return 0;
 229 }
 230
 231 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
 232 {
 233     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
 234     DeviceClass *dc = DEVICE_CLASS(oc);
 235
 236     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
 237     skeyclass->get_skeys = qemu_s390_skeys_get;
 238     skeyclass->set_skeys = qemu_s390_skeys_set;
 239
 240     /* Reason: Internal device (only one skeys device for the whole memory) */
 241     dc->user_creatable = false;
 242 }
 243
 244 static const TypeInfo qemu_s390_skeys_info = {
 245     .name          = TYPE_QEMU_S390_SKEYS,
 246     .parent        = TYPE_S390_SKEYS,
 247     .instance_init = qemu_s390_skeys_init,
 248     .instance_size = sizeof(QEMUS390SKeysState),
 249     .class_init    = qemu_s390_skeys_class_init,
 250     .class_size    = sizeof(S390SKeysClass),
 251 };
 252
 253 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
 254 {
 255     S390SKeysState *ss = S390_SKEYS(opaque);
 256     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 257     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
 258     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
 259     vaddr cur_gfn = 0;
 260     int error = 0;
 261     uint8_t *buf;
 262
 263     if (!skeyclass->skeys_enabled(ss)) {
 264         goto end_stream;
 265     }
 266
 267     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 268     if (!buf) {
 269         error_report("storage key save could not allocate memory");
 270         goto end_stream;
 271     }
 272
 273     /* We only support initial memory. Standby memory is not handled yet. */
 274     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
 275     qemu_put_be64(f, pages_left);
 276
 277     while (pages_left) {
 278         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
 279
 280         if (!error) {
 281             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
 282             if (error) {
 283                 /*
 284                  * If error: we want to fill the stream with valid data instead
 285                  * of stopping early so we pad the stream with 0x00 values and
 286                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
 287                  * reading side.
 288                  */
 289                 error_report("S390_GET_KEYS error %d", error);
 290                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
 291                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
 292             }
 293         }
 294
 295         qemu_put_buffer(f, buf, read_count);
 296         cur_gfn += read_count;
 297         pages_left -= read_count;
 298     }
 299
 300     g_free(buf);
 301 end_stream:
 302     qemu_put_be64(f, eos);
 303 }
 304
 305 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
 306 {
 307     S390SKeysState *ss = S390_SKEYS(opaque);
 308     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 309     int ret = 0;
 310
 311     while (!ret) {
 312         ram_addr_t addr;
 313         int flags;
 314
 315         addr = qemu_get_be64(f);
 316         flags = addr & ~TARGET_PAGE_MASK;
 317         addr &= TARGET_PAGE_MASK;
 318
 319         switch (flags) {
 320         case S390_SKEYS_SAVE_FLAG_SKEYS: {
 321             const uint64_t total_count = qemu_get_be64(f);
 322             uint64_t handled_count = 0, cur_count;
 323             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
 324             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 325
 326             if (!buf) {
 327                 error_report("storage key load could not allocate memory");
 328                 ret = -ENOMEM;
 329                 break;
 330             }
 331
 332             while (handled_count < total_count) {
 333                 cur_count = MIN(total_count - handled_count,
 334                                 S390_SKEYS_BUFFER_SIZE);
 335                 qemu_get_buffer(f, buf, cur_count);
 336
 337                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
 338                 if (ret < 0) {
 339                     error_report("S390_SET_KEYS error %d", ret);
 340                     break;
 341                 }
 342                 handled_count += cur_count;
 343                 cur_gfn += cur_count;
 344             }
 345             g_free(buf);
 346             break;
 347         }
 348         case S390_SKEYS_SAVE_FLAG_ERROR: {
 349             error_report("Storage key data is incomplete");
 350             ret = -EINVAL;
 351             break;
 352         }
 353         case S390_SKEYS_SAVE_FLAG_EOS:
 354             /* normal exit */
 355             return 0;
 356         default:
 357             error_report("Unexpected storage key flag data: %#x", flags);
 358             ret = -EINVAL;
 359         }
 360     }
 361
 362     return ret;
 363 }
 364
 365 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
 366 {
 367     S390SKeysState *ss = S390_SKEYS(obj);
 368
 369     return ss->migration_enabled;
 370 }
 371
 372 static SaveVMHandlers savevm_s390_storage_keys = {
 373     .save_state = s390_storage_keys_save,
 374     .load_state = s390_storage_keys_load,
 375 };
 376
 377 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
 378                                             Error **errp)
 379 {
 380     S390SKeysState *ss = S390_SKEYS(obj);
 381
 382     /* Prevent double registration of savevm handler */
 383     if (ss->migration_enabled == value) {
 384         return;
 385     }
 386
 387     ss->migration_enabled = value;
 388
 389     if (ss->migration_enabled) {
 390         register_savevm_live(NULL, TYPE_S390_SKEYS, 0, 1,
 391                              &savevm_s390_storage_keys, ss);
 392     } else {
 393         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
 394     }
 395 }
 396
 397 static void s390_skeys_instance_init(Object *obj)
 398 {
 399     object_property_add_bool(obj, "migration-enabled",
 400                              s390_skeys_get_migration_enabled,
 401                              s390_skeys_set_migration_enabled, NULL);
 402     object_property_set_bool(obj, true, "migration-enabled", NULL);
 403 }
 404
 405 static void s390_skeys_class_init(ObjectClass *oc, void *data)
 406 {
 407     DeviceClass *dc = DEVICE_CLASS(oc);
 408
 409     dc->hotpluggable = false;
 410     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 411 }
 412
 413 static const TypeInfo s390_skeys_info = {
 414     .name          = TYPE_S390_SKEYS,
 415     .parent        = TYPE_DEVICE,
 416     .instance_init = s390_skeys_instance_init,
 417     .instance_size = sizeof(S390SKeysState),
 418     .class_init    = s390_skeys_class_init,
 419     .class_size    = sizeof(S390SKeysClass),
 420     .abstract = true,
 421 };
 422
 423 static void qemu_s390_skeys_register_types(void)
 424 {
 425     type_register_static(&s390_skeys_info);
 426     type_register_static(&qemu_s390_skeys_info);
 427 }
 428
 429 type_init(qemu_s390_skeys_register_types)