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