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