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 #include "migration/register.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     DeviceClass *dc = DEVICE_CLASS(oc);
 233
 234     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
 235     skeyclass->get_skeys = qemu_s390_skeys_get;
 236     skeyclass->set_skeys = qemu_s390_skeys_set;
 237
 238     /* Reason: Internal device (only one skeys device for the whole memory) */
 239     dc->user_creatable = false;
 240 }
 241
 242 static const TypeInfo qemu_s390_skeys_info = {
 243     .name          = TYPE_QEMU_S390_SKEYS,
 244     .parent        = TYPE_S390_SKEYS,
 245     .instance_init = qemu_s390_skeys_init,
 246     .instance_size = sizeof(QEMUS390SKeysState),
 247     .class_init    = qemu_s390_skeys_class_init,
 248     .class_size    = sizeof(S390SKeysClass),
 249 };
 250
 251 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
 252 {
 253     S390SKeysState *ss = S390_SKEYS(opaque);
 254     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 255     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
 256     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
 257     vaddr cur_gfn = 0;
 258     int error = 0;
 259     uint8_t *buf;
 260
 261     if (!skeyclass->skeys_enabled(ss)) {
 262         goto end_stream;
 263     }
 264
 265     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 266     if (!buf) {
 267         error_report("storage key save could not allocate memory");
 268         goto end_stream;
 269     }
 270
 271     /* We only support initial memory. Standby memory is not handled yet. */
 272     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
 273     qemu_put_be64(f, pages_left);
 274
 275     while (pages_left) {
 276         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
 277
 278         if (!error) {
 279             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
 280             if (error) {
 281                 /*
 282                  * If error: we want to fill the stream with valid data instead
 283                  * of stopping early so we pad the stream with 0x00 values and
 284                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
 285                  * reading side.
 286                  */
 287                 error_report("S390_GET_KEYS error %d", error);
 288                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
 289                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
 290             }
 291         }
 292
 293         qemu_put_buffer(f, buf, read_count);
 294         cur_gfn += read_count;
 295         pages_left -= read_count;
 296     }
 297
 298     g_free(buf);
 299 end_stream:
 300     qemu_put_be64(f, eos);
 301 }
 302
 303 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
 304 {
 305     S390SKeysState *ss = S390_SKEYS(opaque);
 306     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
 307     int ret = 0;
 308
 309     while (!ret) {
 310         ram_addr_t addr;
 311         int flags;
 312
 313         addr = qemu_get_be64(f);
 314         flags = addr & ~TARGET_PAGE_MASK;
 315         addr &= TARGET_PAGE_MASK;
 316
 317         switch (flags) {
 318         case S390_SKEYS_SAVE_FLAG_SKEYS: {
 319             const uint64_t total_count = qemu_get_be64(f);
 320             uint64_t handled_count = 0, cur_count;
 321             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
 322             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
 323
 324             if (!buf) {
 325                 error_report("storage key load could not allocate memory");
 326                 ret = -ENOMEM;
 327                 break;
 328             }
 329
 330             while (handled_count < total_count) {
 331                 cur_count = MIN(total_count - handled_count,
 332                                 S390_SKEYS_BUFFER_SIZE);
 333                 qemu_get_buffer(f, buf, cur_count);
 334
 335                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
 336                 if (ret < 0) {
 337                     error_report("S390_SET_KEYS error %d", ret);
 338                     break;
 339                 }
 340                 handled_count += cur_count;
 341                 cur_gfn += cur_count;
 342             }
 343             g_free(buf);
 344             break;
 345         }
 346         case S390_SKEYS_SAVE_FLAG_ERROR: {
 347             error_report("Storage key data is incomplete");
 348             ret = -EINVAL;
 349             break;
 350         }
 351         case S390_SKEYS_SAVE_FLAG_EOS:
 352             /* normal exit */
 353             return 0;
 354         default:
 355             error_report("Unexpected storage key flag data: %#x", flags);
 356             ret = -EINVAL;
 357         }
 358     }
 359
 360     return ret;
 361 }
 362
 363 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
 364 {
 365     S390SKeysState *ss = S390_SKEYS(obj);
 366
 367     return ss->migration_enabled;
 368 }
 369
 370 static SaveVMHandlers savevm_s390_storage_keys = {
 371     .save_state = s390_storage_keys_save,
 372     .load_state = s390_storage_keys_load,
 373 };
 374
 375 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
 376                                             Error **errp)
 377 {
 378     S390SKeysState *ss = S390_SKEYS(obj);
 379
 380     /* Prevent double registration of savevm handler */
 381     if (ss->migration_enabled == value) {
 382         return;
 383     }
 384
 385     ss->migration_enabled = value;
 386
 387     if (ss->migration_enabled) {
 388         register_savevm_live(NULL, TYPE_S390_SKEYS, 0, 1,
 389                              &savevm_s390_storage_keys, ss);
 390     } else {
 391         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
 392     }
 393 }
 394
 395 static void s390_skeys_instance_init(Object *obj)
 396 {
 397     object_property_add_bool(obj, "migration-enabled",
 398                              s390_skeys_get_migration_enabled,
 399                              s390_skeys_set_migration_enabled, NULL);
 400     object_property_set_bool(obj, true, "migration-enabled", NULL);
 401 }
 402
 403 static void s390_skeys_class_init(ObjectClass *oc, void *data)
 404 {
 405     DeviceClass *dc = DEVICE_CLASS(oc);
 406
 407     dc->hotpluggable = false;
 408     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 409 }
 410
 411 static const TypeInfo s390_skeys_info = {
 412     .name          = TYPE_S390_SKEYS,
 413     .parent        = TYPE_DEVICE,
 414     .instance_init = s390_skeys_instance_init,
 415     .instance_size = sizeof(S390SKeysState),
 416     .class_init    = s390_skeys_class_init,
 417     .class_size    = sizeof(S390SKeysClass),
 418     .abstract = true,
 419 };
 420
 421 static void qemu_s390_skeys_register_types(void)
 422 {
 423     type_register_static(&s390_skeys_info);
 424     type_register_static(&qemu_s390_skeys_info);
 425 }
 426
 427 type_init(qemu_s390_skeys_register_types)