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