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