qemu

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 "qemu/units.h"
14
#include "hw/boards.h"
15
#include "hw/qdev-properties.h"
16
#include "hw/s390x/storage-keys.h"
17
#include "qapi/error.h"
18
#include "qapi/qapi-commands-misc-target.h"
19
#include "qapi/qmp/qdict.h"
20
#include "qemu/error-report.h"
21
#include "sysemu/memory_mapping.h"
22
#include "exec/address-spaces.h"
23
#include "sysemu/kvm.h"
24
#include "migration/qemu-file-types.h"
25
#include "migration/register.h"
26
#include "trace.h"
27

28
#define S390_SKEYS_BUFFER_SIZE (128 * KiB)  /* Room for 128k storage keys */
29
#define S390_SKEYS_SAVE_FLAG_EOS 0x01
30
#define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
31
#define S390_SKEYS_SAVE_FLAG_ERROR 0x04
32

33
S390SKeysState *s390_get_skeys_device(void)
34
{
35
    S390SKeysState *ss;
36

37
    ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
38
    assert(ss);
39
    return ss;
40
}
41

42
void s390_skeys_init(void)
43
{
44
    Object *obj;
45

46
    if (kvm_enabled()) {
47
        obj = object_new(TYPE_KVM_S390_SKEYS);
48
    } else {
49
        obj = object_new(TYPE_QEMU_S390_SKEYS);
50
    }
51
    object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
52
                              obj);
53
    object_unref(obj);
54

55
    qdev_realize(DEVICE(obj), NULL, &error_fatal);
56
}
57

58
int s390_skeys_get(S390SKeysState *ks, uint64_t start_gfn,
59
                   uint64_t count, uint8_t *keys)
60
{
61
    S390SKeysClass *kc = S390_SKEYS_GET_CLASS(ks);
62
    int rc;
63

64
    rc = kc->get_skeys(ks, start_gfn, count, keys);
65
    if (rc) {
66
        trace_s390_skeys_get_nonzero(rc);
67
    }
68
    return rc;
69
}
70

71
int s390_skeys_set(S390SKeysState *ks, uint64_t start_gfn,
72
                   uint64_t count, uint8_t *keys)
73
{
74
    S390SKeysClass *kc = S390_SKEYS_GET_CLASS(ks);
75
    int rc;
76

77
    rc = kc->set_skeys(ks, start_gfn, count, keys);
78
    if (rc) {
79
        trace_s390_skeys_set_nonzero(rc);
80
    }
81
    return rc;
82
}
83

84
static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
85
                       uint64_t count, Error **errp)
86
{
87
    uint64_t curpage = startgfn;
88
    uint64_t maxpage = curpage + count - 1;
89

90
    for (; curpage <= maxpage; curpage++) {
91
        uint8_t acc = (*keys & 0xF0) >> 4;
92
        int fp =  (*keys & 0x08);
93
        int ref = (*keys & 0x04);
94
        int ch = (*keys & 0x02);
95
        int res = (*keys & 0x01);
96

97
        fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
98
                " ch=%d, reserved=%d\n",
99
                curpage, *keys, acc, fp, ref, ch, res);
100
        keys++;
101
    }
102
}
103

104
void hmp_info_skeys(Monitor *mon, const QDict *qdict)
105
{
106
    S390SKeysState *ss = s390_get_skeys_device();
107
    S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
108
    uint64_t addr = qdict_get_int(qdict, "addr");
109
    uint8_t key;
110
    int r;
111

112
    /* Quick check to see if guest is using storage keys*/
113
    if (!skeyclass->skeys_are_enabled(ss)) {
114
        monitor_printf(mon, "Error: This guest is not using storage keys\n");
115
        return;
116
    }
117

118
    if (!address_space_access_valid(&address_space_memory,
119
                                    addr & TARGET_PAGE_MASK, TARGET_PAGE_SIZE,
120
                                    false, MEMTXATTRS_UNSPECIFIED)) {
121
        monitor_printf(mon, "Error: The given address is not valid\n");
122
        return;
123
    }
124

125
    r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
126
    if (r < 0) {
127
        monitor_printf(mon, "Error: %s\n", strerror(-r));
128
        return;
129
    }
130

131
    monitor_printf(mon, "  key: 0x%X\n", key);
132
}
133

134
void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
135
{
136
    const char *filename = qdict_get_str(qdict, "filename");
137
    Error *err = NULL;
138

139
    qmp_dump_skeys(filename, &err);
140
    if (err) {
141
        error_report_err(err);
142
    }
143
}
144

145
void qmp_dump_skeys(const char *filename, Error **errp)
146
{
147
    S390SKeysState *ss = s390_get_skeys_device();
148
    S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
149
    GuestPhysBlockList guest_phys_blocks;
150
    GuestPhysBlock *block;
151
    uint64_t pages, gfn;
152
    Error *lerr = NULL;
153
    uint8_t *buf;
154
    int ret;
155
    int fd;
156
    FILE *f;
157

158
    /* Quick check to see if guest is using storage keys*/
159
    if (!skeyclass->skeys_are_enabled(ss)) {
160
        error_setg(errp, "This guest is not using storage keys - "
161
                         "nothing to dump");
162
        return;
163
    }
164

165
    fd = qemu_open_old(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
166
    if (fd < 0) {
167
        error_setg_file_open(errp, errno, filename);
168
        return;
169
    }
170
    f = fdopen(fd, "wb");
171
    if (!f) {
172
        close(fd);
173
        error_setg_file_open(errp, errno, filename);
174
        return;
175
    }
176

177
    buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
178
    if (!buf) {
179
        error_setg(errp, "Could not allocate memory");
180
        goto out;
181
    }
182

183
    assert(bql_locked());
184
    guest_phys_blocks_init(&guest_phys_blocks);
185
    guest_phys_blocks_append(&guest_phys_blocks);
186

187
    QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) {
188
        assert(QEMU_IS_ALIGNED(block->target_start, TARGET_PAGE_SIZE));
189
        assert(QEMU_IS_ALIGNED(block->target_end, TARGET_PAGE_SIZE));
190

191
        gfn = block->target_start / TARGET_PAGE_SIZE;
192
        pages = (block->target_end - block->target_start) / TARGET_PAGE_SIZE;
193

194
        while (pages) {
195
            const uint64_t cur_pages = MIN(pages, S390_SKEYS_BUFFER_SIZE);
196

197
            ret = skeyclass->get_skeys(ss, gfn, cur_pages, buf);
198
            if (ret < 0) {
199
                error_setg_errno(errp, -ret, "get_keys error");
200
                goto out_free;
201
            }
202

203
            /* write keys to stream */
204
            write_keys(f, buf, gfn, cur_pages, &lerr);
205
            if (lerr) {
206
                goto out_free;
207
            }
208

209
            gfn += cur_pages;
210
            pages -= cur_pages;
211
        }
212
    }
213

214
out_free:
215
    guest_phys_blocks_free(&guest_phys_blocks);
216
    error_propagate(errp, lerr);
217
    g_free(buf);
218
out:
219
    fclose(f);
220
}
221

222
static bool qemu_s390_skeys_are_enabled(S390SKeysState *ss)
223
{
224
    QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(ss);
225

226
    /* Lockless check is sufficient. */
227
    return !!skeys->keydata;
228
}
229

230
static bool qemu_s390_enable_skeys(S390SKeysState *ss)
231
{
232
    QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(ss);
233
    static gsize initialized;
234

235
    if (likely(skeys->keydata)) {
236
        return true;
237
    }
238

239
    /*
240
     * TODO: Modern Linux doesn't use storage keys unless running KVM guests
241
     *       that use storage keys. Therefore, we keep it simple for now.
242
     *
243
     * 1) We should initialize to "referenced+changed" for an initial
244
     *    over-indication. Let's avoid touching megabytes of data for now and
245
     *    assume that any sane user will issue a storage key instruction before
246
     *    actually relying on this data.
247
     * 2) Relying on ram_size and allocating a big array is ugly. We should
248
     *    allocate and manage storage key data per RAMBlock or optimally using
249
     *    some sparse data structure.
250
     * 3) We only ever have a single S390SKeysState, so relying on
251
     *    g_once_init_enter() is good enough.
252
     */
253
    if (g_once_init_enter(&initialized)) {
254
        MachineState *machine = MACHINE(qdev_get_machine());
255

256
        skeys->key_count = machine->ram_size / TARGET_PAGE_SIZE;
257
        skeys->keydata = g_malloc0(skeys->key_count);
258
        g_once_init_leave(&initialized, 1);
259
    }
260
    return false;
261
}
262

263
static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
264
                              uint64_t count, uint8_t *keys)
265
{
266
    QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
267
    int i;
268

269
    /* Check for uint64 overflow and access beyond end of key data */
270
    if (unlikely(!skeydev->keydata || start_gfn + count > skeydev->key_count ||
271
                  start_gfn + count < count)) {
272
        error_report("Error: Setting storage keys for pages with unallocated "
273
                     "storage key memory: gfn=%" PRIx64 " count=%" PRId64,
274
                     start_gfn, count);
275
        return -EINVAL;
276
    }
277

278
    for (i = 0; i < count; i++) {
279
        skeydev->keydata[start_gfn + i] = keys[i];
280
    }
281
    return 0;
282
}
283

284
static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
285
                               uint64_t count, uint8_t *keys)
286
{
287
    QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
288
    int i;
289

290
    /* Check for uint64 overflow and access beyond end of key data */
291
    if (unlikely(!skeydev->keydata || start_gfn + count > skeydev->key_count ||
292
                  start_gfn + count < count)) {
293
        error_report("Error: Getting storage keys for pages with unallocated "
294
                     "storage key memory: gfn=%" PRIx64 " count=%" PRId64,
295
                     start_gfn, count);
296
        return -EINVAL;
297
    }
298

299
    for (i = 0; i < count; i++) {
300
        keys[i] = skeydev->keydata[start_gfn + i];
301
    }
302
    return 0;
303
}
304

305
static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
306
{
307
    S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
308
    DeviceClass *dc = DEVICE_CLASS(oc);
309

310
    skeyclass->skeys_are_enabled = qemu_s390_skeys_are_enabled;
311
    skeyclass->enable_skeys = qemu_s390_enable_skeys;
312
    skeyclass->get_skeys = qemu_s390_skeys_get;
313
    skeyclass->set_skeys = qemu_s390_skeys_set;
314

315
    /* Reason: Internal device (only one skeys device for the whole memory) */
316
    dc->user_creatable = false;
317
}
318

319
static const TypeInfo qemu_s390_skeys_info = {
320
    .name          = TYPE_QEMU_S390_SKEYS,
321
    .parent        = TYPE_S390_SKEYS,
322
    .instance_size = sizeof(QEMUS390SKeysState),
323
    .class_init    = qemu_s390_skeys_class_init,
324
    .class_size    = sizeof(S390SKeysClass),
325
};
326

327
static void s390_storage_keys_save(QEMUFile *f, void *opaque)
328
{
329
    S390SKeysState *ss = S390_SKEYS(opaque);
330
    S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
331
    GuestPhysBlockList guest_phys_blocks;
332
    GuestPhysBlock *block;
333
    uint64_t pages, gfn;
334
    int error = 0;
335
    uint8_t *buf;
336

337
    if (!skeyclass->skeys_are_enabled(ss)) {
338
        goto end_stream;
339
    }
340

341
    buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
342
    if (!buf) {
343
        error_report("storage key save could not allocate memory");
344
        goto end_stream;
345
    }
346

347
    guest_phys_blocks_init(&guest_phys_blocks);
348
    guest_phys_blocks_append(&guest_phys_blocks);
349

350
    /* Send each contiguous physical memory range separately. */
351
    QTAILQ_FOREACH(block, &guest_phys_blocks.head, next) {
352
        assert(QEMU_IS_ALIGNED(block->target_start, TARGET_PAGE_SIZE));
353
        assert(QEMU_IS_ALIGNED(block->target_end, TARGET_PAGE_SIZE));
354

355
        gfn = block->target_start / TARGET_PAGE_SIZE;
356
        pages = (block->target_end - block->target_start) / TARGET_PAGE_SIZE;
357
        qemu_put_be64(f, block->target_start | S390_SKEYS_SAVE_FLAG_SKEYS);
358
        qemu_put_be64(f, pages);
359

360
        while (pages) {
361
            const uint64_t cur_pages = MIN(pages, S390_SKEYS_BUFFER_SIZE);
362

363
            if (!error) {
364
                error = skeyclass->get_skeys(ss, gfn, cur_pages, buf);
365
                if (error) {
366
                    /*
367
                     * Create a valid stream with all 0x00 and indicate
368
                     * S390_SKEYS_SAVE_FLAG_ERROR to the destination.
369
                     */
370
                    error_report("S390_GET_KEYS error %d", error);
371
                    memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
372
                }
373
            }
374

375
            qemu_put_buffer(f, buf, cur_pages);
376
            gfn += cur_pages;
377
            pages -= cur_pages;
378
        }
379

380
        if (error) {
381
            break;
382
        }
383
    }
384

385
    guest_phys_blocks_free(&guest_phys_blocks);
386
    g_free(buf);
387
end_stream:
388
    if (error) {
389
        qemu_put_be64(f, S390_SKEYS_SAVE_FLAG_ERROR);
390
    } else {
391
        qemu_put_be64(f, S390_SKEYS_SAVE_FLAG_EOS);
392
    }
393
}
394

395
static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
396
{
397
    S390SKeysState *ss = S390_SKEYS(opaque);
398
    S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
399
    int ret = 0;
400

401
    /*
402
     * Make sure to lazy-enable if required to be done explicitly. No need to
403
     * flush any TLB as the VM is not running yet.
404
     */
405
    if (skeyclass->enable_skeys) {
406
        skeyclass->enable_skeys(ss);
407
    }
408

409
    while (!ret) {
410
        ram_addr_t addr;
411
        int flags;
412

413
        addr = qemu_get_be64(f);
414
        flags = addr & ~TARGET_PAGE_MASK;
415
        addr &= TARGET_PAGE_MASK;
416

417
        switch (flags) {
418
        case S390_SKEYS_SAVE_FLAG_SKEYS: {
419
            const uint64_t total_count = qemu_get_be64(f);
420
            uint64_t handled_count = 0, cur_count;
421
            uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
422
            uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
423

424
            if (!buf) {
425
                error_report("storage key load could not allocate memory");
426
                ret = -ENOMEM;
427
                break;
428
            }
429

430
            while (handled_count < total_count) {
431
                cur_count = MIN(total_count - handled_count,
432
                                S390_SKEYS_BUFFER_SIZE);
433
                qemu_get_buffer(f, buf, cur_count);
434

435
                ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
436
                if (ret < 0) {
437
                    error_report("S390_SET_KEYS error %d", ret);
438
                    break;
439
                }
440
                handled_count += cur_count;
441
                cur_gfn += cur_count;
442
            }
443
            g_free(buf);
444
            break;
445
        }
446
        case S390_SKEYS_SAVE_FLAG_ERROR: {
447
            error_report("Storage key data is incomplete");
448
            ret = -EINVAL;
449
            break;
450
        }
451
        case S390_SKEYS_SAVE_FLAG_EOS:
452
            /* normal exit */
453
            return 0;
454
        default:
455
            error_report("Unexpected storage key flag data: %#x", flags);
456
            ret = -EINVAL;
457
        }
458
    }
459

460
    return ret;
461
}
462

463
static SaveVMHandlers savevm_s390_storage_keys = {
464
    .save_state = s390_storage_keys_save,
465
    .load_state = s390_storage_keys_load,
466
};
467

468
static void s390_skeys_realize(DeviceState *dev, Error **errp)
469
{
470
    S390SKeysState *ss = S390_SKEYS(dev);
471

472
    if (ss->migration_enabled) {
473
        register_savevm_live(TYPE_S390_SKEYS, 0, 1,
474
                             &savevm_s390_storage_keys, ss);
475
    }
476
}
477

478
static Property s390_skeys_props[] = {
479
    DEFINE_PROP_BOOL("migration-enabled", S390SKeysState, migration_enabled, true),
480
    DEFINE_PROP_END_OF_LIST(),
481
};
482

483
static void s390_skeys_class_init(ObjectClass *oc, void *data)
484
{
485
    DeviceClass *dc = DEVICE_CLASS(oc);
486

487
    dc->hotpluggable = false;
488
    dc->realize = s390_skeys_realize;
489
    device_class_set_props(dc, s390_skeys_props);
490
    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
491
}
492

493
static const TypeInfo s390_skeys_info = {
494
    .name          = TYPE_S390_SKEYS,
495
    .parent        = TYPE_DEVICE,
496
    .instance_size = sizeof(S390SKeysState),
497
    .class_init    = s390_skeys_class_init,
498
    .class_size    = sizeof(S390SKeysClass),
499
    .abstract = true,
500
};
501

502
static void qemu_s390_skeys_register_types(void)
503
{
504
    type_register_static(&s390_skeys_info);
505
    type_register_static(&qemu_s390_skeys_info);
506
}
507

508
type_init(qemu_s390_skeys_register_types)
509