Merge tag 'edgar/xilinx-next-2022-09-21.for-upstream' of https://github.com/edgarigl...
[qemu.git] / hw / block / xen-block.c
1 /*
2 * Copyright (c) 2018 Citrix Systems Inc.
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2 or later.
5 * See the COPYING file in the top-level directory.
6 */
7
8 #include "qemu/osdep.h"
9 #include "qemu/cutils.h"
10 #include "qemu/main-loop.h"
11 #include "qemu/module.h"
12 #include "qemu/option.h"
13 #include "qapi/error.h"
14 #include "qapi/qapi-commands-block-core.h"
15 #include "qapi/qapi-commands-qom.h"
16 #include "qapi/qapi-visit-block-core.h"
17 #include "qapi/qobject-input-visitor.h"
18 #include "qapi/visitor.h"
19 #include "qapi/qmp/qdict.h"
20 #include "qapi/qmp/qstring.h"
21 #include "qom/object_interfaces.h"
22 #include "hw/xen/xen_common.h"
23 #include "hw/block/xen_blkif.h"
24 #include "hw/qdev-properties.h"
25 #include "hw/xen/xen-block.h"
26 #include "hw/xen/xen-backend.h"
27 #include "sysemu/blockdev.h"
28 #include "sysemu/block-backend.h"
29 #include "sysemu/iothread.h"
30 #include "dataplane/xen-block.h"
31 #include "trace.h"
32
33 static char *xen_block_get_name(XenDevice *xendev, Error **errp)
34 {
35 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
36 XenBlockVdev *vdev = &blockdev->props.vdev;
37
38 return g_strdup_printf("%lu", vdev->number);
39 }
40
41 static void xen_block_disconnect(XenDevice *xendev, Error **errp)
42 {
43 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
44 const char *type = object_get_typename(OBJECT(blockdev));
45 XenBlockVdev *vdev = &blockdev->props.vdev;
46
47 trace_xen_block_disconnect(type, vdev->disk, vdev->partition);
48
49 xen_block_dataplane_stop(blockdev->dataplane);
50 }
51
52 static void xen_block_connect(XenDevice *xendev, Error **errp)
53 {
54 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
55 const char *type = object_get_typename(OBJECT(blockdev));
56 XenBlockVdev *vdev = &blockdev->props.vdev;
57 BlockConf *conf = &blockdev->props.conf;
58 unsigned int feature_large_sector_size;
59 unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol;
60 char *str;
61
62 trace_xen_block_connect(type, vdev->disk, vdev->partition);
63
64 if (xen_device_frontend_scanf(xendev, "feature-large-sector-size", "%u",
65 &feature_large_sector_size) != 1) {
66 feature_large_sector_size = 0;
67 }
68
69 if (feature_large_sector_size != 1 &&
70 conf->logical_block_size != XEN_BLKIF_SECTOR_SIZE) {
71 error_setg(errp, "logical_block_size != %u not supported by frontend",
72 XEN_BLKIF_SECTOR_SIZE);
73 return;
74 }
75
76 if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u",
77 &order) != 1) {
78 nr_ring_ref = 1;
79 ring_ref = g_new(unsigned int, nr_ring_ref);
80
81 if (xen_device_frontend_scanf(xendev, "ring-ref", "%u",
82 &ring_ref[0]) != 1) {
83 error_setg(errp, "failed to read ring-ref");
84 g_free(ring_ref);
85 return;
86 }
87 } else if (order <= blockdev->props.max_ring_page_order) {
88 unsigned int i;
89
90 nr_ring_ref = 1 << order;
91 ring_ref = g_new(unsigned int, nr_ring_ref);
92
93 for (i = 0; i < nr_ring_ref; i++) {
94 const char *key = g_strdup_printf("ring-ref%u", i);
95
96 if (xen_device_frontend_scanf(xendev, key, "%u",
97 &ring_ref[i]) != 1) {
98 error_setg(errp, "failed to read %s", key);
99 g_free((gpointer)key);
100 g_free(ring_ref);
101 return;
102 }
103
104 g_free((gpointer)key);
105 }
106 } else {
107 error_setg(errp, "invalid ring-page-order (%d)", order);
108 return;
109 }
110
111 if (xen_device_frontend_scanf(xendev, "event-channel", "%u",
112 &event_channel) != 1) {
113 error_setg(errp, "failed to read event-channel");
114 g_free(ring_ref);
115 return;
116 }
117
118 if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
119 &str) != 1) {
120 protocol = BLKIF_PROTOCOL_NATIVE;
121 } else {
122 if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
123 protocol = BLKIF_PROTOCOL_X86_32;
124 } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) {
125 protocol = BLKIF_PROTOCOL_X86_64;
126 } else {
127 protocol = BLKIF_PROTOCOL_NATIVE;
128 }
129
130 free(str);
131 }
132
133 xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref,
134 event_channel, protocol, errp);
135
136 g_free(ring_ref);
137 }
138
139 static void xen_block_unrealize(XenDevice *xendev)
140 {
141 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
142 XenBlockDeviceClass *blockdev_class =
143 XEN_BLOCK_DEVICE_GET_CLASS(xendev);
144 const char *type = object_get_typename(OBJECT(blockdev));
145 XenBlockVdev *vdev = &blockdev->props.vdev;
146
147 if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
148 return;
149 }
150
151 trace_xen_block_unrealize(type, vdev->disk, vdev->partition);
152
153 /* Disconnect from the frontend in case this has not already happened */
154 xen_block_disconnect(xendev, NULL);
155
156 xen_block_dataplane_destroy(blockdev->dataplane);
157 blockdev->dataplane = NULL;
158
159 if (blockdev_class->unrealize) {
160 blockdev_class->unrealize(blockdev);
161 }
162 }
163
164 static void xen_block_set_size(XenBlockDevice *blockdev)
165 {
166 const char *type = object_get_typename(OBJECT(blockdev));
167 XenBlockVdev *vdev = &blockdev->props.vdev;
168 BlockConf *conf = &blockdev->props.conf;
169 int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size;
170 XenDevice *xendev = XEN_DEVICE(blockdev);
171
172 trace_xen_block_size(type, vdev->disk, vdev->partition, sectors);
173
174 xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors);
175 }
176
177 static void xen_block_resize_cb(void *opaque)
178 {
179 XenBlockDevice *blockdev = opaque;
180 XenDevice *xendev = XEN_DEVICE(blockdev);
181 enum xenbus_state state = xen_device_backend_get_state(xendev);
182
183 xen_block_set_size(blockdev);
184
185 /*
186 * Mimic the behaviour of Linux xen-blkback and re-write the state
187 * to trigger the frontend watch.
188 */
189 xen_device_backend_printf(xendev, "state", "%u", state);
190 }
191
192 static const BlockDevOps xen_block_dev_ops = {
193 .resize_cb = xen_block_resize_cb,
194 };
195
196 static void xen_block_realize(XenDevice *xendev, Error **errp)
197 {
198 ERRP_GUARD();
199 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
200 XenBlockDeviceClass *blockdev_class =
201 XEN_BLOCK_DEVICE_GET_CLASS(xendev);
202 const char *type = object_get_typename(OBJECT(blockdev));
203 XenBlockVdev *vdev = &blockdev->props.vdev;
204 BlockConf *conf = &blockdev->props.conf;
205 BlockBackend *blk = conf->blk;
206
207 if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
208 error_setg(errp, "vdev property not set");
209 return;
210 }
211
212 trace_xen_block_realize(type, vdev->disk, vdev->partition);
213
214 if (blockdev_class->realize) {
215 blockdev_class->realize(blockdev, errp);
216 if (*errp) {
217 return;
218 }
219 }
220
221 /*
222 * The blkif protocol does not deal with removable media, so it must
223 * always be present, even for CDRom devices.
224 */
225 assert(blk);
226 if (!blk_is_inserted(blk)) {
227 error_setg(errp, "device needs media, but drive is empty");
228 return;
229 }
230
231 if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY,
232 true, errp)) {
233 return;
234 }
235
236 if (!(blockdev->info & VDISK_CDROM) &&
237 !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) {
238 return;
239 }
240
241 if (!blkconf_blocksizes(conf, errp)) {
242 return;
243 }
244
245 blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev);
246 blk_set_guest_block_size(blk, conf->logical_block_size);
247
248 if (conf->discard_granularity == -1) {
249 conf->discard_granularity = conf->physical_block_size;
250 }
251
252 if (blk_get_flags(blk) & BDRV_O_UNMAP) {
253 xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
254 xen_device_backend_printf(xendev, "discard-granularity", "%u",
255 conf->discard_granularity);
256 xen_device_backend_printf(xendev, "discard-alignment", "%u", 0);
257 }
258
259 xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
260 xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
261 blockdev->props.max_ring_page_order);
262 xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
263
264 xen_device_frontend_printf(xendev, "virtual-device", "%lu",
265 vdev->number);
266 xen_device_frontend_printf(xendev, "device-type", "%s",
267 blockdev->device_type);
268
269 xen_device_backend_printf(xendev, "sector-size", "%u",
270 conf->logical_block_size);
271
272 xen_block_set_size(blockdev);
273
274 blockdev->dataplane =
275 xen_block_dataplane_create(xendev, blk, conf->logical_block_size,
276 blockdev->props.iothread);
277 }
278
279 static void xen_block_frontend_changed(XenDevice *xendev,
280 enum xenbus_state frontend_state,
281 Error **errp)
282 {
283 ERRP_GUARD();
284 enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
285
286 switch (frontend_state) {
287 case XenbusStateInitialised:
288 case XenbusStateConnected:
289 if (backend_state == XenbusStateConnected) {
290 break;
291 }
292
293 xen_block_disconnect(xendev, errp);
294 if (*errp) {
295 break;
296 }
297
298 xen_block_connect(xendev, errp);
299 if (*errp) {
300 break;
301 }
302
303 xen_device_backend_set_state(xendev, XenbusStateConnected);
304 break;
305
306 case XenbusStateClosing:
307 xen_device_backend_set_state(xendev, XenbusStateClosing);
308 break;
309
310 case XenbusStateClosed:
311 case XenbusStateUnknown:
312 xen_block_disconnect(xendev, errp);
313 if (*errp) {
314 break;
315 }
316
317 xen_device_backend_set_state(xendev, XenbusStateClosed);
318 break;
319
320 default:
321 break;
322 }
323 }
324
325 static char *disk_to_vbd_name(unsigned int disk)
326 {
327 char *name, *prefix = (disk >= 26) ?
328 disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
329
330 name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26);
331 g_free(prefix);
332
333 return name;
334 }
335
336 static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name,
337 void *opaque, Error **errp)
338 {
339 Property *prop = opaque;
340 XenBlockVdev *vdev = object_field_prop_ptr(obj, prop);
341 char *str;
342
343 switch (vdev->type) {
344 case XEN_BLOCK_VDEV_TYPE_DP:
345 str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition);
346 break;
347
348 case XEN_BLOCK_VDEV_TYPE_XVD:
349 case XEN_BLOCK_VDEV_TYPE_HD:
350 case XEN_BLOCK_VDEV_TYPE_SD: {
351 char *name = disk_to_vbd_name(vdev->disk);
352
353 str = g_strdup_printf("%s%s%lu",
354 (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ?
355 "xvd" :
356 (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ?
357 "hd" :
358 "sd",
359 name, vdev->partition);
360 g_free(name);
361 break;
362 }
363 default:
364 error_setg(errp, "invalid vdev type");
365 return;
366 }
367
368 visit_type_str(v, name, &str, errp);
369 g_free(str);
370 }
371
372 static int vbd_name_to_disk(const char *name, const char **endp,
373 unsigned long *disk)
374 {
375 unsigned int n = 0;
376
377 while (*name != '\0') {
378 if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
379 break;
380 }
381
382 n *= 26;
383 n += *name++ - 'a' + 1;
384 }
385 *endp = name;
386
387 if (!n) {
388 return -1;
389 }
390
391 *disk = n - 1;
392
393 return 0;
394 }
395
396 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
397 void *opaque, Error **errp)
398 {
399 Property *prop = opaque;
400 XenBlockVdev *vdev = object_field_prop_ptr(obj, prop);
401 char *str, *p;
402 const char *end;
403
404 if (!visit_type_str(v, name, &str, errp)) {
405 return;
406 }
407
408 p = strchr(str, 'd');
409 if (!p) {
410 goto invalid;
411 }
412
413 *p++ = '\0';
414 if (*str == '\0') {
415 vdev->type = XEN_BLOCK_VDEV_TYPE_DP;
416 } else if (strcmp(str, "xv") == 0) {
417 vdev->type = XEN_BLOCK_VDEV_TYPE_XVD;
418 } else if (strcmp(str, "h") == 0) {
419 vdev->type = XEN_BLOCK_VDEV_TYPE_HD;
420 } else if (strcmp(str, "s") == 0) {
421 vdev->type = XEN_BLOCK_VDEV_TYPE_SD;
422 } else {
423 goto invalid;
424 }
425
426 if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) {
427 if (qemu_strtoul(p, &end, 10, &vdev->disk)) {
428 goto invalid;
429 }
430
431 if (*end == 'p') {
432 if (*(++end) == '\0') {
433 goto invalid;
434 }
435 }
436 } else {
437 if (vbd_name_to_disk(p, &end, &vdev->disk)) {
438 goto invalid;
439 }
440 }
441
442 if (*end != '\0') {
443 p = (char *)end;
444
445 if (qemu_strtoul(p, &end, 10, &vdev->partition)) {
446 goto invalid;
447 }
448
449 if (*end != '\0') {
450 goto invalid;
451 }
452 } else {
453 vdev->partition = 0;
454 }
455
456 switch (vdev->type) {
457 case XEN_BLOCK_VDEV_TYPE_DP:
458 case XEN_BLOCK_VDEV_TYPE_XVD:
459 if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
460 vdev->number = (202 << 8) | (vdev->disk << 4) |
461 vdev->partition;
462 } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) {
463 vdev->number = (1 << 28) | (vdev->disk << 8) |
464 vdev->partition;
465 } else {
466 goto invalid;
467 }
468 break;
469
470 case XEN_BLOCK_VDEV_TYPE_HD:
471 if ((vdev->disk == 0 || vdev->disk == 1) &&
472 vdev->partition < (1 << 6)) {
473 vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition;
474 } else if ((vdev->disk == 2 || vdev->disk == 3) &&
475 vdev->partition < (1 << 6)) {
476 vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) |
477 vdev->partition;
478 } else {
479 goto invalid;
480 }
481 break;
482
483 case XEN_BLOCK_VDEV_TYPE_SD:
484 if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) {
485 vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition;
486 } else {
487 goto invalid;
488 }
489 break;
490
491 default:
492 goto invalid;
493 }
494
495 g_free(str);
496 return;
497
498 invalid:
499 error_setg(errp, "invalid virtual disk specifier");
500
501 vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID;
502 g_free(str);
503 }
504
505 /*
506 * This property deals with 'vdev' names adhering to the Xen VBD naming
507 * scheme described in:
508 *
509 * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html
510 */
511 const PropertyInfo xen_block_prop_vdev = {
512 .name = "str",
513 .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*",
514 .get = xen_block_get_vdev,
515 .set = xen_block_set_vdev,
516 };
517
518 static Property xen_block_props[] = {
519 DEFINE_PROP("vdev", XenBlockDevice, props.vdev,
520 xen_block_prop_vdev, XenBlockVdev),
521 DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf),
522 DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
523 props.max_ring_page_order, 4),
524 DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread,
525 TYPE_IOTHREAD, IOThread *),
526 DEFINE_PROP_END_OF_LIST()
527 };
528
529 static void xen_block_class_init(ObjectClass *class, void *data)
530 {
531 DeviceClass *dev_class = DEVICE_CLASS(class);
532 XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
533
534 xendev_class->backend = "qdisk";
535 xendev_class->device = "vbd";
536 xendev_class->get_name = xen_block_get_name;
537 xendev_class->realize = xen_block_realize;
538 xendev_class->frontend_changed = xen_block_frontend_changed;
539 xendev_class->unrealize = xen_block_unrealize;
540
541 device_class_set_props(dev_class, xen_block_props);
542 }
543
544 static const TypeInfo xen_block_type_info = {
545 .name = TYPE_XEN_BLOCK_DEVICE,
546 .parent = TYPE_XEN_DEVICE,
547 .instance_size = sizeof(XenBlockDevice),
548 .abstract = true,
549 .class_size = sizeof(XenBlockDeviceClass),
550 .class_init = xen_block_class_init,
551 };
552
553 static void xen_disk_unrealize(XenBlockDevice *blockdev)
554 {
555 trace_xen_disk_unrealize();
556 }
557
558 static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
559 {
560 BlockConf *conf = &blockdev->props.conf;
561
562 trace_xen_disk_realize();
563
564 blockdev->device_type = "disk";
565
566 if (!conf->blk) {
567 error_setg(errp, "drive property not set");
568 return;
569 }
570
571 blockdev->info = blk_supports_write_perm(conf->blk) ? 0 : VDISK_READONLY;
572 }
573
574 static void xen_disk_class_init(ObjectClass *class, void *data)
575 {
576 DeviceClass *dev_class = DEVICE_CLASS(class);
577 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
578
579 blockdev_class->realize = xen_disk_realize;
580 blockdev_class->unrealize = xen_disk_unrealize;
581
582 dev_class->desc = "Xen Disk Device";
583 }
584
585 static const TypeInfo xen_disk_type_info = {
586 .name = TYPE_XEN_DISK_DEVICE,
587 .parent = TYPE_XEN_BLOCK_DEVICE,
588 .instance_size = sizeof(XenDiskDevice),
589 .class_init = xen_disk_class_init,
590 };
591
592 static void xen_cdrom_unrealize(XenBlockDevice *blockdev)
593 {
594 trace_xen_cdrom_unrealize();
595 }
596
597 static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
598 {
599 BlockConf *conf = &blockdev->props.conf;
600
601 trace_xen_cdrom_realize();
602
603 blockdev->device_type = "cdrom";
604
605 if (!conf->blk) {
606 int rc;
607
608 /* Set up an empty drive */
609 conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
610
611 rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
612 if (!rc) {
613 error_setg_errno(errp, -rc, "failed to create drive");
614 return;
615 }
616 }
617
618 blockdev->info = VDISK_READONLY | VDISK_CDROM;
619 }
620
621 static void xen_cdrom_class_init(ObjectClass *class, void *data)
622 {
623 DeviceClass *dev_class = DEVICE_CLASS(class);
624 XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class);
625
626 blockdev_class->realize = xen_cdrom_realize;
627 blockdev_class->unrealize = xen_cdrom_unrealize;
628
629 dev_class->desc = "Xen CD-ROM Device";
630 }
631
632 static const TypeInfo xen_cdrom_type_info = {
633 .name = TYPE_XEN_CDROM_DEVICE,
634 .parent = TYPE_XEN_BLOCK_DEVICE,
635 .instance_size = sizeof(XenCDRomDevice),
636 .class_init = xen_cdrom_class_init,
637 };
638
639 static void xen_block_register_types(void)
640 {
641 type_register_static(&xen_block_type_info);
642 type_register_static(&xen_disk_type_info);
643 type_register_static(&xen_cdrom_type_info);
644 }
645
646 type_init(xen_block_register_types)
647
648 static void xen_block_blockdev_del(const char *node_name, Error **errp)
649 {
650 trace_xen_block_blockdev_del(node_name);
651
652 qmp_blockdev_del(node_name, errp);
653 }
654
655 static char *xen_block_blockdev_add(const char *id, QDict *qdict,
656 Error **errp)
657 {
658 ERRP_GUARD();
659 const char *driver = qdict_get_try_str(qdict, "driver");
660 BlockdevOptions *options = NULL;
661 char *node_name;
662 Visitor *v;
663
664 if (!driver) {
665 error_setg(errp, "no 'driver' parameter");
666 return NULL;
667 }
668
669 node_name = g_strdup_printf("%s-%s", id, driver);
670 qdict_put_str(qdict, "node-name", node_name);
671
672 trace_xen_block_blockdev_add(node_name);
673
674 v = qobject_input_visitor_new(QOBJECT(qdict));
675 visit_type_BlockdevOptions(v, NULL, &options, errp);
676 visit_free(v);
677 if (!options) {
678 goto fail;
679 }
680
681 qmp_blockdev_add(options, errp);
682
683 if (*errp) {
684 goto fail;
685 }
686
687 qapi_free_BlockdevOptions(options);
688
689 return node_name;
690
691 fail:
692 if (options) {
693 qapi_free_BlockdevOptions(options);
694 }
695 g_free(node_name);
696
697 return NULL;
698 }
699
700 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
701 {
702 ERRP_GUARD();
703 char *node_name = drive->node_name;
704
705 if (node_name) {
706 xen_block_blockdev_del(node_name, errp);
707 if (*errp) {
708 return;
709 }
710 g_free(node_name);
711 drive->node_name = NULL;
712 }
713 g_free(drive->id);
714 g_free(drive);
715 }
716
717 static XenBlockDrive *xen_block_drive_create(const char *id,
718 const char *device_type,
719 QDict *opts, Error **errp)
720 {
721 ERRP_GUARD();
722 const char *params = qdict_get_try_str(opts, "params");
723 const char *mode = qdict_get_try_str(opts, "mode");
724 const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
725 const char *discard_enable = qdict_get_try_str(opts, "discard-enable");
726 char *driver = NULL;
727 char *filename = NULL;
728 XenBlockDrive *drive = NULL;
729 QDict *file_layer;
730 QDict *driver_layer;
731 struct stat st;
732 int rc;
733
734 if (params) {
735 char **v = g_strsplit(params, ":", 2);
736
737 if (v[1] == NULL) {
738 filename = g_strdup(v[0]);
739 driver = g_strdup("raw");
740 } else {
741 if (strcmp(v[0], "aio") == 0) {
742 driver = g_strdup("raw");
743 } else if (strcmp(v[0], "vhd") == 0) {
744 driver = g_strdup("vpc");
745 } else {
746 driver = g_strdup(v[0]);
747 }
748 filename = g_strdup(v[1]);
749 }
750
751 g_strfreev(v);
752 } else {
753 error_setg(errp, "no params");
754 goto done;
755 }
756
757 assert(filename);
758 assert(driver);
759
760 drive = g_new0(XenBlockDrive, 1);
761 drive->id = g_strdup(id);
762
763 file_layer = qdict_new();
764 driver_layer = qdict_new();
765
766 rc = stat(filename, &st);
767 if (rc) {
768 error_setg_errno(errp, errno, "Could not stat file '%s'", filename);
769 goto done;
770 }
771 if (S_ISBLK(st.st_mode)) {
772 qdict_put_str(file_layer, "driver", "host_device");
773 } else {
774 qdict_put_str(file_layer, "driver", "file");
775 }
776
777 qdict_put_str(file_layer, "filename", filename);
778 g_free(filename);
779
780 if (mode && *mode != 'w') {
781 qdict_put_bool(file_layer, "read-only", true);
782 }
783
784 if (direct_io_safe) {
785 unsigned long value;
786
787 if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) {
788 QDict *cache_qdict = qdict_new();
789
790 qdict_put_bool(cache_qdict, "direct", true);
791 qdict_put(file_layer, "cache", cache_qdict);
792
793 qdict_put_str(file_layer, "aio", "native");
794 }
795 }
796
797 if (discard_enable) {
798 unsigned long value;
799
800 if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) {
801 qdict_put_str(file_layer, "discard", "unmap");
802 qdict_put_str(driver_layer, "discard", "unmap");
803 }
804 }
805
806 /*
807 * It is necessary to turn file locking off as an emulated device
808 * may have already opened the same image file.
809 */
810 qdict_put_str(file_layer, "locking", "off");
811
812 qdict_put_str(driver_layer, "driver", driver);
813 g_free(driver);
814
815 qdict_put(driver_layer, "file", file_layer);
816
817 g_assert(!drive->node_name);
818 drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
819 errp);
820
821 qobject_unref(driver_layer);
822
823 done:
824 if (*errp) {
825 xen_block_drive_destroy(drive, NULL);
826 return NULL;
827 }
828
829 return drive;
830 }
831
832 static const char *xen_block_drive_get_node_name(XenBlockDrive *drive)
833 {
834 return drive->node_name ? drive->node_name : "";
835 }
836
837 static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
838 Error **errp)
839 {
840 qmp_object_del(iothread->id, errp);
841
842 g_free(iothread->id);
843 g_free(iothread);
844 }
845
846 static XenBlockIOThread *xen_block_iothread_create(const char *id,
847 Error **errp)
848 {
849 ERRP_GUARD();
850 XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
851 ObjectOptions *opts;
852
853 iothread->id = g_strdup(id);
854
855 opts = g_new(ObjectOptions, 1);
856 *opts = (ObjectOptions) {
857 .qom_type = OBJECT_TYPE_IOTHREAD,
858 .id = g_strdup(id),
859 };
860 qmp_object_add(opts, errp);
861 qapi_free_ObjectOptions(opts);
862
863 if (*errp) {
864 g_free(iothread->id);
865 g_free(iothread);
866 return NULL;
867 }
868
869 return iothread;
870 }
871
872 static void xen_block_device_create(XenBackendInstance *backend,
873 QDict *opts, Error **errp)
874 {
875 ERRP_GUARD();
876 XenBus *xenbus = xen_backend_get_bus(backend);
877 const char *name = xen_backend_get_name(backend);
878 unsigned long number;
879 const char *vdev, *device_type;
880 XenBlockDrive *drive = NULL;
881 XenBlockIOThread *iothread = NULL;
882 XenDevice *xendev = NULL;
883 const char *type;
884 XenBlockDevice *blockdev;
885
886 if (qemu_strtoul(name, NULL, 10, &number)) {
887 error_setg(errp, "failed to parse name '%s'", name);
888 goto fail;
889 }
890
891 trace_xen_block_device_create(number);
892
893 vdev = qdict_get_try_str(opts, "dev");
894 if (!vdev) {
895 error_setg(errp, "no dev parameter");
896 goto fail;
897 }
898
899 device_type = qdict_get_try_str(opts, "device-type");
900 if (!device_type) {
901 error_setg(errp, "no device-type parameter");
902 goto fail;
903 }
904
905 if (!strcmp(device_type, "disk")) {
906 type = TYPE_XEN_DISK_DEVICE;
907 } else if (!strcmp(device_type, "cdrom")) {
908 type = TYPE_XEN_CDROM_DEVICE;
909 } else {
910 error_setg(errp, "invalid device-type parameter '%s'", device_type);
911 goto fail;
912 }
913
914 drive = xen_block_drive_create(vdev, device_type, opts, errp);
915 if (!drive) {
916 error_prepend(errp, "failed to create drive: ");
917 goto fail;
918 }
919
920 iothread = xen_block_iothread_create(vdev, errp);
921 if (*errp) {
922 error_prepend(errp, "failed to create iothread: ");
923 goto fail;
924 }
925
926 xendev = XEN_DEVICE(qdev_new(type));
927 blockdev = XEN_BLOCK_DEVICE(xendev);
928
929 if (!object_property_set_str(OBJECT(xendev), "vdev", vdev,
930 errp)) {
931 error_prepend(errp, "failed to set 'vdev': ");
932 goto fail;
933 }
934
935 if (!object_property_set_str(OBJECT(xendev), "drive",
936 xen_block_drive_get_node_name(drive),
937 errp)) {
938 error_prepend(errp, "failed to set 'drive': ");
939 goto fail;
940 }
941
942 if (!object_property_set_str(OBJECT(xendev), "iothread", iothread->id,
943 errp)) {
944 error_prepend(errp, "failed to set 'iothread': ");
945 goto fail;
946 }
947
948 blockdev->iothread = iothread;
949 blockdev->drive = drive;
950
951 if (!qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) {
952 error_prepend(errp, "realization of device %s failed: ", type);
953 goto fail;
954 }
955
956 xen_backend_set_device(backend, xendev);
957 return;
958
959 fail:
960 if (xendev) {
961 object_unparent(OBJECT(xendev));
962 }
963
964 if (iothread) {
965 xen_block_iothread_destroy(iothread, NULL);
966 }
967
968 if (drive) {
969 xen_block_drive_destroy(drive, NULL);
970 }
971 }
972
973 static void xen_block_device_destroy(XenBackendInstance *backend,
974 Error **errp)
975 {
976 ERRP_GUARD();
977 XenDevice *xendev = xen_backend_get_device(backend);
978 XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
979 XenBlockVdev *vdev = &blockdev->props.vdev;
980 XenBlockDrive *drive = blockdev->drive;
981 XenBlockIOThread *iothread = blockdev->iothread;
982
983 trace_xen_block_device_destroy(vdev->number);
984
985 object_unparent(OBJECT(xendev));
986
987 /*
988 * Drain all pending RCU callbacks as object_unparent() frees `xendev'
989 * in a RCU callback.
990 * And due to the property "drive" still existing in `xendev', we
991 * can't destroy the XenBlockDrive associated with `xendev' with
992 * xen_block_drive_destroy() below.
993 */
994 drain_call_rcu();
995
996 if (iothread) {
997 xen_block_iothread_destroy(iothread, errp);
998 if (*errp) {
999 error_prepend(errp, "failed to destroy iothread: ");
1000 return;
1001 }
1002 }
1003
1004 if (drive) {
1005 xen_block_drive_destroy(drive, errp);
1006 if (*errp) {
1007 error_prepend(errp, "failed to destroy drive: ");
1008 return;
1009 }
1010 }
1011 }
1012
1013 static const XenBackendInfo xen_block_backend_info = {
1014 .type = "qdisk",
1015 .create = xen_block_device_create,
1016 .destroy = xen_block_device_destroy,
1017 };
1018
1019 static void xen_block_register_backend(void)
1020 {
1021 xen_backend_register(&xen_block_backend_info);
1022 }
1023
1024 xen_backend_init(xen_block_register_backend);