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6e02c38d AL |
1 | /* |
2 | * Virtio Block Device | |
3 | * | |
4 | * Copyright IBM, Corp. 2007 | |
5 | * | |
6 | * Authors: | |
7 | * Anthony Liguori <aliguori@us.ibm.com> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
10 | * the COPYING file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
869a5c6d AL |
14 | #include <qemu-common.h> |
15 | #include <sysemu.h> | |
6e02c38d AL |
16 | #include "virtio-blk.h" |
17 | #include "block_int.h" | |
1063b8b1 CH |
18 | #ifdef __linux__ |
19 | # include <scsi/sg.h> | |
20 | #endif | |
6e02c38d AL |
21 | |
22 | typedef struct VirtIOBlock | |
23 | { | |
24 | VirtIODevice vdev; | |
25 | BlockDriverState *bs; | |
26 | VirtQueue *vq; | |
869a5c6d | 27 | void *rq; |
bf011293 | 28 | char serial_str[BLOCK_SERIAL_STRLEN + 1]; |
213189ab | 29 | QEMUBH *bh; |
6e02c38d AL |
30 | } VirtIOBlock; |
31 | ||
32 | static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev) | |
33 | { | |
34 | return (VirtIOBlock *)vdev; | |
35 | } | |
36 | ||
bf011293 | 37 | /* store identify data in little endian format |
38 | */ | |
39 | static inline void put_le16(uint16_t *p, unsigned int v) | |
40 | { | |
41 | *p = cpu_to_le16(v); | |
42 | } | |
43 | ||
44 | /* copy to *dst from *src, nul pad dst tail as needed to len bytes | |
45 | */ | |
46 | static inline void padstr(char *dst, const char *src, int len) | |
47 | { | |
48 | while (len--) | |
49 | *dst++ = *src ? *src++ : '\0'; | |
50 | } | |
51 | ||
52 | /* setup simulated identify data as appropriate for virtio block device | |
53 | * | |
54 | * ref: AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS) | |
55 | */ | |
56 | static inline void virtio_identify_template(struct virtio_blk_config *bc) | |
57 | { | |
58 | uint16_t *p = &bc->identify[0]; | |
59 | uint64_t lba_sectors = bc->capacity; | |
60 | ||
61 | memset(p, 0, sizeof(bc->identify)); | |
62 | put_le16(p + 0, 0x0); /* ATA device */ | |
63 | padstr((char *)(p + 23), QEMU_VERSION, 8); /* firmware revision */ | |
64 | padstr((char *)(p + 27), "QEMU VIRT_BLK", 40); /* model# */ | |
65 | put_le16(p + 47, 0x80ff); /* max xfer 255 sectors */ | |
66 | put_le16(p + 49, 0x0b00); /* support IORDY/LBA/DMA */ | |
67 | put_le16(p + 59, 0x1ff); /* cur xfer 255 sectors */ | |
68 | put_le16(p + 80, 0x1f0); /* support ATA8/7/6/5/4 */ | |
69 | put_le16(p + 81, 0x16); | |
70 | put_le16(p + 82, 0x400); | |
71 | put_le16(p + 83, 0x400); | |
72 | put_le16(p + 100, lba_sectors); | |
73 | put_le16(p + 101, lba_sectors >> 16); | |
74 | put_le16(p + 102, lba_sectors >> 32); | |
75 | put_le16(p + 103, lba_sectors >> 48); | |
76 | } | |
77 | ||
6e02c38d AL |
78 | typedef struct VirtIOBlockReq |
79 | { | |
80 | VirtIOBlock *dev; | |
81 | VirtQueueElement elem; | |
82 | struct virtio_blk_inhdr *in; | |
83 | struct virtio_blk_outhdr *out; | |
1063b8b1 | 84 | struct virtio_scsi_inhdr *scsi; |
d28a1b6e | 85 | QEMUIOVector qiov; |
869a5c6d | 86 | struct VirtIOBlockReq *next; |
6e02c38d AL |
87 | } VirtIOBlockReq; |
88 | ||
869a5c6d AL |
89 | static void virtio_blk_req_complete(VirtIOBlockReq *req, int status) |
90 | { | |
91 | VirtIOBlock *s = req->dev; | |
92 | ||
93 | req->in->status = status; | |
d28a1b6e | 94 | virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in)); |
869a5c6d AL |
95 | virtio_notify(&s->vdev, s->vq); |
96 | ||
869a5c6d AL |
97 | qemu_free(req); |
98 | } | |
99 | ||
100 | static int virtio_blk_handle_write_error(VirtIOBlockReq *req, int error) | |
101 | { | |
102 | BlockInterfaceErrorAction action = drive_get_onerror(req->dev->bs); | |
103 | VirtIOBlock *s = req->dev; | |
104 | ||
105 | if (action == BLOCK_ERR_IGNORE) | |
106 | return 0; | |
107 | ||
108 | if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC) | |
109 | || action == BLOCK_ERR_STOP_ANY) { | |
110 | req->next = s->rq; | |
111 | s->rq = req; | |
112 | vm_stop(0); | |
113 | } else { | |
114 | virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); | |
115 | } | |
116 | ||
117 | return 1; | |
118 | } | |
119 | ||
6e02c38d AL |
120 | static void virtio_blk_rw_complete(void *opaque, int ret) |
121 | { | |
122 | VirtIOBlockReq *req = opaque; | |
6e02c38d | 123 | |
d28a1b6e | 124 | if (ret && (req->out->type & VIRTIO_BLK_T_OUT)) { |
869a5c6d AL |
125 | if (virtio_blk_handle_write_error(req, -ret)) |
126 | return; | |
6e02c38d AL |
127 | } |
128 | ||
869a5c6d AL |
129 | virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); |
130 | } | |
6e02c38d | 131 | |
869a5c6d AL |
132 | static VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s) |
133 | { | |
134 | VirtIOBlockReq *req = qemu_mallocz(sizeof(*req)); | |
487414f1 | 135 | req->dev = s; |
869a5c6d | 136 | return req; |
6e02c38d AL |
137 | } |
138 | ||
139 | static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s) | |
140 | { | |
869a5c6d | 141 | VirtIOBlockReq *req = virtio_blk_alloc_request(s); |
6e02c38d | 142 | |
869a5c6d AL |
143 | if (req != NULL) { |
144 | if (!virtqueue_pop(s->vq, &req->elem)) { | |
145 | qemu_free(req); | |
146 | return NULL; | |
147 | } | |
6e02c38d AL |
148 | } |
149 | ||
150 | return req; | |
151 | } | |
152 | ||
1063b8b1 CH |
153 | #ifdef __linux__ |
154 | static void virtio_blk_handle_scsi(VirtIOBlockReq *req) | |
155 | { | |
156 | struct sg_io_hdr hdr; | |
157 | int ret, size = 0; | |
158 | int status; | |
159 | int i; | |
160 | ||
161 | /* | |
162 | * We require at least one output segment each for the virtio_blk_outhdr | |
163 | * and the SCSI command block. | |
164 | * | |
165 | * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr | |
166 | * and the sense buffer pointer in the input segments. | |
167 | */ | |
168 | if (req->elem.out_num < 2 || req->elem.in_num < 3) { | |
169 | virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); | |
170 | return; | |
171 | } | |
172 | ||
173 | /* | |
174 | * No support for bidirection commands yet. | |
175 | */ | |
176 | if (req->elem.out_num > 2 && req->elem.in_num > 3) { | |
177 | virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); | |
178 | return; | |
179 | } | |
180 | ||
181 | /* | |
182 | * The scsi inhdr is placed in the second-to-last input segment, just | |
183 | * before the regular inhdr. | |
184 | */ | |
185 | req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base; | |
186 | size = sizeof(*req->in) + sizeof(*req->scsi); | |
187 | ||
188 | memset(&hdr, 0, sizeof(struct sg_io_hdr)); | |
189 | hdr.interface_id = 'S'; | |
190 | hdr.cmd_len = req->elem.out_sg[1].iov_len; | |
191 | hdr.cmdp = req->elem.out_sg[1].iov_base; | |
192 | hdr.dxfer_len = 0; | |
193 | ||
194 | if (req->elem.out_num > 2) { | |
195 | /* | |
196 | * If there are more than the minimally required 2 output segments | |
197 | * there is write payload starting from the third iovec. | |
198 | */ | |
199 | hdr.dxfer_direction = SG_DXFER_TO_DEV; | |
200 | hdr.iovec_count = req->elem.out_num - 2; | |
201 | ||
202 | for (i = 0; i < hdr.iovec_count; i++) | |
203 | hdr.dxfer_len += req->elem.out_sg[i + 2].iov_len; | |
204 | ||
205 | hdr.dxferp = req->elem.out_sg + 2; | |
206 | ||
207 | } else if (req->elem.in_num > 3) { | |
208 | /* | |
209 | * If we have more than 3 input segments the guest wants to actually | |
210 | * read data. | |
211 | */ | |
212 | hdr.dxfer_direction = SG_DXFER_FROM_DEV; | |
213 | hdr.iovec_count = req->elem.in_num - 3; | |
214 | for (i = 0; i < hdr.iovec_count; i++) | |
215 | hdr.dxfer_len += req->elem.in_sg[i].iov_len; | |
216 | ||
217 | hdr.dxferp = req->elem.in_sg; | |
218 | size += hdr.dxfer_len; | |
219 | } else { | |
220 | /* | |
221 | * Some SCSI commands don't actually transfer any data. | |
222 | */ | |
223 | hdr.dxfer_direction = SG_DXFER_NONE; | |
224 | } | |
225 | ||
226 | hdr.sbp = req->elem.in_sg[req->elem.in_num - 3].iov_base; | |
227 | hdr.mx_sb_len = req->elem.in_sg[req->elem.in_num - 3].iov_len; | |
228 | size += hdr.mx_sb_len; | |
229 | ||
230 | ret = bdrv_ioctl(req->dev->bs, SG_IO, &hdr); | |
231 | if (ret) { | |
232 | status = VIRTIO_BLK_S_UNSUPP; | |
233 | hdr.status = ret; | |
234 | hdr.resid = hdr.dxfer_len; | |
235 | } else if (hdr.status) { | |
236 | status = VIRTIO_BLK_S_IOERR; | |
237 | } else { | |
238 | status = VIRTIO_BLK_S_OK; | |
239 | } | |
240 | ||
241 | req->scsi->errors = hdr.status; | |
242 | req->scsi->residual = hdr.resid; | |
243 | req->scsi->sense_len = hdr.sb_len_wr; | |
244 | req->scsi->data_len = hdr.dxfer_len; | |
245 | ||
246 | virtio_blk_req_complete(req, status); | |
247 | } | |
248 | #else | |
249 | static void virtio_blk_handle_scsi(VirtIOBlockReq *req) | |
250 | { | |
251 | virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); | |
252 | } | |
253 | #endif /* __linux__ */ | |
254 | ||
d28a1b6e | 255 | static void virtio_blk_handle_write(VirtIOBlockReq *req) |
869a5c6d | 256 | { |
87b245db CH |
257 | BlockDriverAIOCB *acb; |
258 | ||
259 | acb = bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov, | |
260 | req->qiov.size / 512, virtio_blk_rw_complete, req); | |
261 | if (!acb) { | |
262 | virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); | |
263 | } | |
d28a1b6e | 264 | } |
869a5c6d | 265 | |
d28a1b6e AL |
266 | static void virtio_blk_handle_read(VirtIOBlockReq *req) |
267 | { | |
87b245db CH |
268 | BlockDriverAIOCB *acb; |
269 | ||
270 | acb = bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov, | |
271 | req->qiov.size / 512, virtio_blk_rw_complete, req); | |
272 | if (!acb) { | |
273 | virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); | |
274 | } | |
869a5c6d AL |
275 | } |
276 | ||
6e02c38d AL |
277 | static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
278 | { | |
279 | VirtIOBlock *s = to_virtio_blk(vdev); | |
280 | VirtIOBlockReq *req; | |
281 | ||
282 | while ((req = virtio_blk_get_request(s))) { | |
6e02c38d AL |
283 | if (req->elem.out_num < 1 || req->elem.in_num < 1) { |
284 | fprintf(stderr, "virtio-blk missing headers\n"); | |
285 | exit(1); | |
286 | } | |
287 | ||
288 | if (req->elem.out_sg[0].iov_len < sizeof(*req->out) || | |
289 | req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) { | |
290 | fprintf(stderr, "virtio-blk header not in correct element\n"); | |
291 | exit(1); | |
292 | } | |
293 | ||
294 | req->out = (void *)req->elem.out_sg[0].iov_base; | |
295 | req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base; | |
296 | ||
297 | if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) { | |
1063b8b1 | 298 | virtio_blk_handle_scsi(req); |
6e02c38d | 299 | } else if (req->out->type & VIRTIO_BLK_T_OUT) { |
d28a1b6e AL |
300 | qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1], |
301 | req->elem.out_num - 1); | |
302 | virtio_blk_handle_write(req); | |
6e02c38d | 303 | } else { |
d28a1b6e AL |
304 | qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0], |
305 | req->elem.in_num - 1); | |
306 | virtio_blk_handle_read(req); | |
6e02c38d AL |
307 | } |
308 | } | |
309 | /* | |
310 | * FIXME: Want to check for completions before returning to guest mode, | |
311 | * so cached reads and writes are reported as quickly as possible. But | |
312 | * that should be done in the generic block layer. | |
313 | */ | |
314 | } | |
315 | ||
213189ab | 316 | static void virtio_blk_dma_restart_bh(void *opaque) |
869a5c6d AL |
317 | { |
318 | VirtIOBlock *s = opaque; | |
319 | VirtIOBlockReq *req = s->rq; | |
320 | ||
213189ab MA |
321 | qemu_bh_delete(s->bh); |
322 | s->bh = NULL; | |
869a5c6d AL |
323 | |
324 | s->rq = NULL; | |
325 | ||
326 | while (req) { | |
327 | virtio_blk_handle_write(req); | |
328 | req = req->next; | |
329 | } | |
330 | } | |
331 | ||
213189ab MA |
332 | static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason) |
333 | { | |
334 | VirtIOBlock *s = opaque; | |
335 | ||
336 | if (!running) | |
337 | return; | |
338 | ||
339 | if (!s->bh) { | |
340 | s->bh = qemu_bh_new(virtio_blk_dma_restart_bh, s); | |
341 | qemu_bh_schedule(s->bh); | |
342 | } | |
343 | } | |
344 | ||
6e02c38d AL |
345 | static void virtio_blk_reset(VirtIODevice *vdev) |
346 | { | |
347 | /* | |
348 | * This should cancel pending requests, but can't do nicely until there | |
349 | * are per-device request lists. | |
350 | */ | |
351 | qemu_aio_flush(); | |
352 | } | |
353 | ||
bf011293 | 354 | /* coalesce internal state, copy to pci i/o region 0 |
355 | */ | |
6e02c38d AL |
356 | static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) |
357 | { | |
358 | VirtIOBlock *s = to_virtio_blk(vdev); | |
359 | struct virtio_blk_config blkcfg; | |
360 | uint64_t capacity; | |
361 | int cylinders, heads, secs; | |
362 | ||
363 | bdrv_get_geometry(s->bs, &capacity); | |
364 | bdrv_get_geometry_hint(s->bs, &cylinders, &heads, &secs); | |
5c5dafdc | 365 | memset(&blkcfg, 0, sizeof(blkcfg)); |
6e02c38d AL |
366 | stq_raw(&blkcfg.capacity, capacity); |
367 | stl_raw(&blkcfg.seg_max, 128 - 2); | |
368 | stw_raw(&blkcfg.cylinders, cylinders); | |
369 | blkcfg.heads = heads; | |
370 | blkcfg.sectors = secs; | |
c7085da7 | 371 | blkcfg.size_max = 0; |
bf011293 | 372 | virtio_identify_template(&blkcfg); |
373 | memcpy(&blkcfg.identify[VIRTIO_BLK_ID_SN], s->serial_str, | |
374 | VIRTIO_BLK_ID_SN_BYTES); | |
6e02c38d AL |
375 | memcpy(config, &blkcfg, sizeof(blkcfg)); |
376 | } | |
377 | ||
378 | static uint32_t virtio_blk_get_features(VirtIODevice *vdev) | |
379 | { | |
bf011293 | 380 | VirtIOBlock *s = to_virtio_blk(vdev); |
1063b8b1 CH |
381 | uint32_t features = 0; |
382 | ||
383 | features |= (1 << VIRTIO_BLK_F_SEG_MAX); | |
384 | features |= (1 << VIRTIO_BLK_F_GEOMETRY); | |
385 | #ifdef __linux__ | |
386 | features |= (1 << VIRTIO_BLK_F_SCSI); | |
387 | #endif | |
bf011293 | 388 | if (strcmp(s->serial_str, "0")) |
389 | features |= 1 << VIRTIO_BLK_F_IDENTIFY; | |
1063b8b1 CH |
390 | |
391 | return features; | |
6e02c38d AL |
392 | } |
393 | ||
394 | static void virtio_blk_save(QEMUFile *f, void *opaque) | |
395 | { | |
396 | VirtIOBlock *s = opaque; | |
869a5c6d AL |
397 | VirtIOBlockReq *req = s->rq; |
398 | ||
6e02c38d | 399 | virtio_save(&s->vdev, f); |
869a5c6d AL |
400 | |
401 | while (req) { | |
402 | qemu_put_sbyte(f, 1); | |
403 | qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem)); | |
404 | req = req->next; | |
405 | } | |
406 | qemu_put_sbyte(f, 0); | |
6e02c38d AL |
407 | } |
408 | ||
409 | static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id) | |
410 | { | |
411 | VirtIOBlock *s = opaque; | |
412 | ||
869a5c6d | 413 | if (version_id != 2) |
6e02c38d AL |
414 | return -EINVAL; |
415 | ||
416 | virtio_load(&s->vdev, f); | |
869a5c6d AL |
417 | while (qemu_get_sbyte(f)) { |
418 | VirtIOBlockReq *req = virtio_blk_alloc_request(s); | |
419 | qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem)); | |
420 | req->next = s->rq; | |
421 | s->rq = req->next; | |
422 | } | |
6e02c38d AL |
423 | |
424 | return 0; | |
425 | } | |
426 | ||
d176c495 | 427 | VirtIODevice *virtio_blk_init(DeviceState *dev, DriveInfo *dinfo) |
6e02c38d AL |
428 | { |
429 | VirtIOBlock *s; | |
430 | int cylinders, heads, secs; | |
431 | static int virtio_blk_id; | |
bf011293 | 432 | char *ps; |
cf21e106 | 433 | |
53c25cea PB |
434 | s = (VirtIOBlock *)virtio_common_init("virtio-blk", VIRTIO_ID_BLOCK, |
435 | sizeof(struct virtio_blk_config), | |
436 | sizeof(VirtIOBlock)); | |
6e02c38d AL |
437 | |
438 | s->vdev.get_config = virtio_blk_update_config; | |
439 | s->vdev.get_features = virtio_blk_get_features; | |
440 | s->vdev.reset = virtio_blk_reset; | |
d176c495 | 441 | s->bs = dinfo->bdrv; |
869a5c6d | 442 | s->rq = NULL; |
d176c495 | 443 | if (strlen(ps = (char *)drive_get_serial(s->bs))) |
bf011293 | 444 | strncpy(s->serial_str, ps, sizeof(s->serial_str)); |
445 | else | |
446 | snprintf(s->serial_str, sizeof(s->serial_str), "0"); | |
d176c495 | 447 | s->bs->private = dev; |
6e02c38d AL |
448 | bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs); |
449 | bdrv_set_geometry_hint(s->bs, cylinders, heads, secs); | |
450 | ||
451 | s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output); | |
452 | ||
869a5c6d AL |
453 | qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); |
454 | register_savevm("virtio-blk", virtio_blk_id++, 2, | |
6e02c38d AL |
455 | virtio_blk_save, virtio_blk_load, s); |
456 | ||
53c25cea | 457 | return &s->vdev; |
6e02c38d | 458 | } |