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