root / hw / xen_disk.c @ c65adf9b
History | View | Annotate | Download (23.1 kB)
1 |
/*
|
---|---|
2 |
* xen paravirt block device backend
|
3 |
*
|
4 |
* (c) Gerd Hoffmann <kraxel@redhat.com>
|
5 |
*
|
6 |
* This program is free software; you can redistribute it and/or modify
|
7 |
* it under the terms of the GNU General Public License as published by
|
8 |
* the Free Software Foundation; under version 2 of the License.
|
9 |
*
|
10 |
* This program is distributed in the hope that it will be useful,
|
11 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
12 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
13 |
* GNU General Public License for more details.
|
14 |
*
|
15 |
* You should have received a copy of the GNU General Public License along
|
16 |
* with this program; if not, see <http://www.gnu.org/licenses/>.
|
17 |
*/
|
18 |
|
19 |
#include <stdio.h> |
20 |
#include <stdlib.h> |
21 |
#include <stdarg.h> |
22 |
#include <string.h> |
23 |
#include <unistd.h> |
24 |
#include <signal.h> |
25 |
#include <inttypes.h> |
26 |
#include <time.h> |
27 |
#include <fcntl.h> |
28 |
#include <errno.h> |
29 |
#include <sys/ioctl.h> |
30 |
#include <sys/types.h> |
31 |
#include <sys/stat.h> |
32 |
#include <sys/mman.h> |
33 |
#include <sys/uio.h> |
34 |
|
35 |
#include <xs.h> |
36 |
#include <xenctrl.h> |
37 |
#include <xen/io/xenbus.h> |
38 |
|
39 |
#include "hw.h" |
40 |
#include "block_int.h" |
41 |
#include "qemu-char.h" |
42 |
#include "xen_blkif.h" |
43 |
#include "xen_backend.h" |
44 |
#include "blockdev.h" |
45 |
|
46 |
/* ------------------------------------------------------------- */
|
47 |
|
48 |
static int syncwrite = 0; |
49 |
static int batch_maps = 0; |
50 |
|
51 |
static int max_requests = 32; |
52 |
|
53 |
/* ------------------------------------------------------------- */
|
54 |
|
55 |
#define BLOCK_SIZE 512 |
56 |
#define IOCB_COUNT (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2) |
57 |
|
58 |
struct ioreq {
|
59 |
blkif_request_t req; |
60 |
int16_t status; |
61 |
|
62 |
/* parsed request */
|
63 |
off_t start; |
64 |
QEMUIOVector v; |
65 |
int presync;
|
66 |
int postsync;
|
67 |
|
68 |
/* grant mapping */
|
69 |
uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
70 |
uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
71 |
int prot;
|
72 |
void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
73 |
void *pages;
|
74 |
|
75 |
/* aio status */
|
76 |
int aio_inflight;
|
77 |
int aio_errors;
|
78 |
|
79 |
struct XenBlkDev *blkdev;
|
80 |
QLIST_ENTRY(ioreq) list; |
81 |
BlockAcctCookie acct; |
82 |
}; |
83 |
|
84 |
struct XenBlkDev {
|
85 |
struct XenDevice xendev; /* must be first */ |
86 |
char *params;
|
87 |
char *mode;
|
88 |
char *type;
|
89 |
char *dev;
|
90 |
char *devtype;
|
91 |
const char *fileproto; |
92 |
const char *filename; |
93 |
int ring_ref;
|
94 |
void *sring;
|
95 |
int64_t file_blk; |
96 |
int64_t file_size; |
97 |
int protocol;
|
98 |
blkif_back_rings_t rings; |
99 |
int more_work;
|
100 |
int cnt_map;
|
101 |
|
102 |
/* request lists */
|
103 |
QLIST_HEAD(inflight_head, ioreq) inflight; |
104 |
QLIST_HEAD(finished_head, ioreq) finished; |
105 |
QLIST_HEAD(freelist_head, ioreq) freelist; |
106 |
int requests_total;
|
107 |
int requests_inflight;
|
108 |
int requests_finished;
|
109 |
|
110 |
/* qemu block driver */
|
111 |
DriveInfo *dinfo; |
112 |
BlockDriverState *bs; |
113 |
QEMUBH *bh; |
114 |
}; |
115 |
|
116 |
/* ------------------------------------------------------------- */
|
117 |
|
118 |
static struct ioreq *ioreq_start(struct XenBlkDev *blkdev) |
119 |
{ |
120 |
struct ioreq *ioreq = NULL; |
121 |
|
122 |
if (QLIST_EMPTY(&blkdev->freelist)) {
|
123 |
if (blkdev->requests_total >= max_requests) {
|
124 |
goto out;
|
125 |
} |
126 |
/* allocate new struct */
|
127 |
ioreq = g_malloc0(sizeof(*ioreq));
|
128 |
ioreq->blkdev = blkdev; |
129 |
blkdev->requests_total++; |
130 |
qemu_iovec_init(&ioreq->v, BLKIF_MAX_SEGMENTS_PER_REQUEST); |
131 |
} else {
|
132 |
/* get one from freelist */
|
133 |
ioreq = QLIST_FIRST(&blkdev->freelist); |
134 |
QLIST_REMOVE(ioreq, list); |
135 |
qemu_iovec_reset(&ioreq->v); |
136 |
} |
137 |
QLIST_INSERT_HEAD(&blkdev->inflight, ioreq, list); |
138 |
blkdev->requests_inflight++; |
139 |
|
140 |
out:
|
141 |
return ioreq;
|
142 |
} |
143 |
|
144 |
static void ioreq_finish(struct ioreq *ioreq) |
145 |
{ |
146 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
147 |
|
148 |
QLIST_REMOVE(ioreq, list); |
149 |
QLIST_INSERT_HEAD(&blkdev->finished, ioreq, list); |
150 |
blkdev->requests_inflight--; |
151 |
blkdev->requests_finished++; |
152 |
} |
153 |
|
154 |
static void ioreq_release(struct ioreq *ioreq) |
155 |
{ |
156 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
157 |
|
158 |
QLIST_REMOVE(ioreq, list); |
159 |
memset(ioreq, 0, sizeof(*ioreq)); |
160 |
ioreq->blkdev = blkdev; |
161 |
QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list); |
162 |
blkdev->requests_finished--; |
163 |
} |
164 |
|
165 |
/*
|
166 |
* translate request into iovec + start offset
|
167 |
* do sanity checks along the way
|
168 |
*/
|
169 |
static int ioreq_parse(struct ioreq *ioreq) |
170 |
{ |
171 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
172 |
uintptr_t mem; |
173 |
size_t len; |
174 |
int i;
|
175 |
|
176 |
xen_be_printf(&blkdev->xendev, 3,
|
177 |
"op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n", |
178 |
ioreq->req.operation, ioreq->req.nr_segments, |
179 |
ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number); |
180 |
switch (ioreq->req.operation) {
|
181 |
case BLKIF_OP_READ:
|
182 |
ioreq->prot = PROT_WRITE; /* to memory */
|
183 |
break;
|
184 |
case BLKIF_OP_WRITE_BARRIER:
|
185 |
if (!ioreq->req.nr_segments) {
|
186 |
ioreq->presync = 1;
|
187 |
return 0; |
188 |
} |
189 |
if (!syncwrite) {
|
190 |
ioreq->presync = ioreq->postsync = 1;
|
191 |
} |
192 |
/* fall through */
|
193 |
case BLKIF_OP_WRITE:
|
194 |
ioreq->prot = PROT_READ; /* from memory */
|
195 |
if (syncwrite) {
|
196 |
ioreq->postsync = 1;
|
197 |
} |
198 |
break;
|
199 |
default:
|
200 |
xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n", |
201 |
ioreq->req.operation); |
202 |
goto err;
|
203 |
}; |
204 |
|
205 |
if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') { |
206 |
xen_be_printf(&blkdev->xendev, 0, "error: write req for ro device\n"); |
207 |
goto err;
|
208 |
} |
209 |
|
210 |
ioreq->start = ioreq->req.sector_number * blkdev->file_blk; |
211 |
for (i = 0; i < ioreq->req.nr_segments; i++) { |
212 |
if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
|
213 |
xen_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n"); |
214 |
goto err;
|
215 |
} |
216 |
if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) {
|
217 |
xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n"); |
218 |
goto err;
|
219 |
} |
220 |
if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) {
|
221 |
xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n"); |
222 |
goto err;
|
223 |
} |
224 |
|
225 |
ioreq->domids[i] = blkdev->xendev.dom; |
226 |
ioreq->refs[i] = ioreq->req.seg[i].gref; |
227 |
|
228 |
mem = ioreq->req.seg[i].first_sect * blkdev->file_blk; |
229 |
len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk;
|
230 |
qemu_iovec_add(&ioreq->v, (void*)mem, len);
|
231 |
} |
232 |
if (ioreq->start + ioreq->v.size > blkdev->file_size) {
|
233 |
xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n"); |
234 |
goto err;
|
235 |
} |
236 |
return 0; |
237 |
|
238 |
err:
|
239 |
ioreq->status = BLKIF_RSP_ERROR; |
240 |
return -1; |
241 |
} |
242 |
|
243 |
static void ioreq_unmap(struct ioreq *ioreq) |
244 |
{ |
245 |
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
246 |
int i;
|
247 |
|
248 |
if (ioreq->v.niov == 0) { |
249 |
return;
|
250 |
} |
251 |
if (batch_maps) {
|
252 |
if (!ioreq->pages) {
|
253 |
return;
|
254 |
} |
255 |
if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->v.niov) != 0) { |
256 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
257 |
strerror(errno)); |
258 |
} |
259 |
ioreq->blkdev->cnt_map -= ioreq->v.niov; |
260 |
ioreq->pages = NULL;
|
261 |
} else {
|
262 |
for (i = 0; i < ioreq->v.niov; i++) { |
263 |
if (!ioreq->page[i]) {
|
264 |
continue;
|
265 |
} |
266 |
if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0) { |
267 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
268 |
strerror(errno)); |
269 |
} |
270 |
ioreq->blkdev->cnt_map--; |
271 |
ioreq->page[i] = NULL;
|
272 |
} |
273 |
} |
274 |
} |
275 |
|
276 |
static int ioreq_map(struct ioreq *ioreq) |
277 |
{ |
278 |
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
279 |
int i;
|
280 |
|
281 |
if (ioreq->v.niov == 0) { |
282 |
return 0; |
283 |
} |
284 |
if (batch_maps) {
|
285 |
ioreq->pages = xc_gnttab_map_grant_refs |
286 |
(gnt, ioreq->v.niov, ioreq->domids, ioreq->refs, ioreq->prot); |
287 |
if (ioreq->pages == NULL) { |
288 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
|
289 |
"can't map %d grant refs (%s, %d maps)\n",
|
290 |
ioreq->v.niov, strerror(errno), ioreq->blkdev->cnt_map); |
291 |
return -1; |
292 |
} |
293 |
for (i = 0; i < ioreq->v.niov; i++) { |
294 |
ioreq->v.iov[i].iov_base = ioreq->pages + i * XC_PAGE_SIZE + |
295 |
(uintptr_t)ioreq->v.iov[i].iov_base; |
296 |
} |
297 |
ioreq->blkdev->cnt_map += ioreq->v.niov; |
298 |
} else {
|
299 |
for (i = 0; i < ioreq->v.niov; i++) { |
300 |
ioreq->page[i] = xc_gnttab_map_grant_ref |
301 |
(gnt, ioreq->domids[i], ioreq->refs[i], ioreq->prot); |
302 |
if (ioreq->page[i] == NULL) { |
303 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
|
304 |
"can't map grant ref %d (%s, %d maps)\n",
|
305 |
ioreq->refs[i], strerror(errno), ioreq->blkdev->cnt_map); |
306 |
ioreq_unmap(ioreq); |
307 |
return -1; |
308 |
} |
309 |
ioreq->v.iov[i].iov_base = ioreq->page[i] + (uintptr_t)ioreq->v.iov[i].iov_base; |
310 |
ioreq->blkdev->cnt_map++; |
311 |
} |
312 |
} |
313 |
return 0; |
314 |
} |
315 |
|
316 |
static void qemu_aio_complete(void *opaque, int ret) |
317 |
{ |
318 |
struct ioreq *ioreq = opaque;
|
319 |
|
320 |
if (ret != 0) { |
321 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n", |
322 |
ioreq->req.operation == BLKIF_OP_READ ? "read" : "write"); |
323 |
ioreq->aio_errors++; |
324 |
} |
325 |
|
326 |
ioreq->aio_inflight--; |
327 |
if (ioreq->aio_inflight > 0) { |
328 |
return;
|
329 |
} |
330 |
|
331 |
ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY; |
332 |
ioreq_unmap(ioreq); |
333 |
ioreq_finish(ioreq); |
334 |
bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct); |
335 |
qemu_bh_schedule(ioreq->blkdev->bh); |
336 |
} |
337 |
|
338 |
static int ioreq_runio_qemu_aio(struct ioreq *ioreq) |
339 |
{ |
340 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
341 |
|
342 |
if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) { |
343 |
goto err_no_map;
|
344 |
} |
345 |
|
346 |
ioreq->aio_inflight++; |
347 |
if (ioreq->presync) {
|
348 |
bdrv_flush(blkdev->bs); /* FIXME: aio_flush() ??? */
|
349 |
} |
350 |
|
351 |
switch (ioreq->req.operation) {
|
352 |
case BLKIF_OP_READ:
|
353 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_READ); |
354 |
ioreq->aio_inflight++; |
355 |
bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE, |
356 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
357 |
qemu_aio_complete, ioreq); |
358 |
break;
|
359 |
case BLKIF_OP_WRITE:
|
360 |
case BLKIF_OP_WRITE_BARRIER:
|
361 |
if (!ioreq->req.nr_segments) {
|
362 |
break;
|
363 |
} |
364 |
|
365 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_WRITE); |
366 |
ioreq->aio_inflight++; |
367 |
bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE, |
368 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
369 |
qemu_aio_complete, ioreq); |
370 |
break;
|
371 |
default:
|
372 |
/* unknown operation (shouldn't happen -- parse catches this) */
|
373 |
goto err;
|
374 |
} |
375 |
|
376 |
if (ioreq->postsync) {
|
377 |
bdrv_flush(blkdev->bs); /* FIXME: aio_flush() ??? */
|
378 |
} |
379 |
qemu_aio_complete(ioreq, 0);
|
380 |
|
381 |
return 0; |
382 |
|
383 |
err:
|
384 |
ioreq_unmap(ioreq); |
385 |
err_no_map:
|
386 |
ioreq_finish(ioreq); |
387 |
ioreq->status = BLKIF_RSP_ERROR; |
388 |
return -1; |
389 |
} |
390 |
|
391 |
static int blk_send_response_one(struct ioreq *ioreq) |
392 |
{ |
393 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
394 |
int send_notify = 0; |
395 |
int have_requests = 0; |
396 |
blkif_response_t resp; |
397 |
void *dst;
|
398 |
|
399 |
resp.id = ioreq->req.id; |
400 |
resp.operation = ioreq->req.operation; |
401 |
resp.status = ioreq->status; |
402 |
|
403 |
/* Place on the response ring for the relevant domain. */
|
404 |
switch (blkdev->protocol) {
|
405 |
case BLKIF_PROTOCOL_NATIVE:
|
406 |
dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt); |
407 |
break;
|
408 |
case BLKIF_PROTOCOL_X86_32:
|
409 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part, |
410 |
blkdev->rings.x86_32_part.rsp_prod_pvt); |
411 |
break;
|
412 |
case BLKIF_PROTOCOL_X86_64:
|
413 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part, |
414 |
blkdev->rings.x86_64_part.rsp_prod_pvt); |
415 |
break;
|
416 |
default:
|
417 |
dst = NULL;
|
418 |
} |
419 |
memcpy(dst, &resp, sizeof(resp));
|
420 |
blkdev->rings.common.rsp_prod_pvt++; |
421 |
|
422 |
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify); |
423 |
if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
|
424 |
/*
|
425 |
* Tail check for pending requests. Allows frontend to avoid
|
426 |
* notifications if requests are already in flight (lower
|
427 |
* overheads and promotes batching).
|
428 |
*/
|
429 |
RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests); |
430 |
} else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) { |
431 |
have_requests = 1;
|
432 |
} |
433 |
|
434 |
if (have_requests) {
|
435 |
blkdev->more_work++; |
436 |
} |
437 |
return send_notify;
|
438 |
} |
439 |
|
440 |
/* walk finished list, send outstanding responses, free requests */
|
441 |
static void blk_send_response_all(struct XenBlkDev *blkdev) |
442 |
{ |
443 |
struct ioreq *ioreq;
|
444 |
int send_notify = 0; |
445 |
|
446 |
while (!QLIST_EMPTY(&blkdev->finished)) {
|
447 |
ioreq = QLIST_FIRST(&blkdev->finished); |
448 |
send_notify += blk_send_response_one(ioreq); |
449 |
ioreq_release(ioreq); |
450 |
} |
451 |
if (send_notify) {
|
452 |
xen_be_send_notify(&blkdev->xendev); |
453 |
} |
454 |
} |
455 |
|
456 |
static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc) |
457 |
{ |
458 |
switch (blkdev->protocol) {
|
459 |
case BLKIF_PROTOCOL_NATIVE:
|
460 |
memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc), |
461 |
sizeof(ioreq->req));
|
462 |
break;
|
463 |
case BLKIF_PROTOCOL_X86_32:
|
464 |
blkif_get_x86_32_req(&ioreq->req, |
465 |
RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc)); |
466 |
break;
|
467 |
case BLKIF_PROTOCOL_X86_64:
|
468 |
blkif_get_x86_64_req(&ioreq->req, |
469 |
RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc)); |
470 |
break;
|
471 |
} |
472 |
return 0; |
473 |
} |
474 |
|
475 |
static void blk_handle_requests(struct XenBlkDev *blkdev) |
476 |
{ |
477 |
RING_IDX rc, rp; |
478 |
struct ioreq *ioreq;
|
479 |
|
480 |
blkdev->more_work = 0;
|
481 |
|
482 |
rc = blkdev->rings.common.req_cons; |
483 |
rp = blkdev->rings.common.sring->req_prod; |
484 |
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
|
485 |
|
486 |
blk_send_response_all(blkdev); |
487 |
while (rc != rp) {
|
488 |
/* pull request from ring */
|
489 |
if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
|
490 |
break;
|
491 |
} |
492 |
ioreq = ioreq_start(blkdev); |
493 |
if (ioreq == NULL) { |
494 |
blkdev->more_work++; |
495 |
break;
|
496 |
} |
497 |
blk_get_request(blkdev, ioreq, rc); |
498 |
blkdev->rings.common.req_cons = ++rc; |
499 |
|
500 |
/* parse them */
|
501 |
if (ioreq_parse(ioreq) != 0) { |
502 |
if (blk_send_response_one(ioreq)) {
|
503 |
xen_be_send_notify(&blkdev->xendev); |
504 |
} |
505 |
ioreq_release(ioreq); |
506 |
continue;
|
507 |
} |
508 |
|
509 |
ioreq_runio_qemu_aio(ioreq); |
510 |
} |
511 |
|
512 |
if (blkdev->more_work && blkdev->requests_inflight < max_requests) {
|
513 |
qemu_bh_schedule(blkdev->bh); |
514 |
} |
515 |
} |
516 |
|
517 |
/* ------------------------------------------------------------- */
|
518 |
|
519 |
static void blk_bh(void *opaque) |
520 |
{ |
521 |
struct XenBlkDev *blkdev = opaque;
|
522 |
blk_handle_requests(blkdev); |
523 |
} |
524 |
|
525 |
static void blk_alloc(struct XenDevice *xendev) |
526 |
{ |
527 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
528 |
|
529 |
QLIST_INIT(&blkdev->inflight); |
530 |
QLIST_INIT(&blkdev->finished); |
531 |
QLIST_INIT(&blkdev->freelist); |
532 |
blkdev->bh = qemu_bh_new(blk_bh, blkdev); |
533 |
if (xen_mode != XEN_EMULATE) {
|
534 |
batch_maps = 1;
|
535 |
} |
536 |
} |
537 |
|
538 |
static int blk_init(struct XenDevice *xendev) |
539 |
{ |
540 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
541 |
int index, qflags, info = 0; |
542 |
|
543 |
/* read xenstore entries */
|
544 |
if (blkdev->params == NULL) { |
545 |
char *h = NULL; |
546 |
blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params");
|
547 |
if (blkdev->params != NULL) { |
548 |
h = strchr(blkdev->params, ':');
|
549 |
} |
550 |
if (h != NULL) { |
551 |
blkdev->fileproto = blkdev->params; |
552 |
blkdev->filename = h+1;
|
553 |
*h = 0;
|
554 |
} else {
|
555 |
blkdev->fileproto = "<unset>";
|
556 |
blkdev->filename = blkdev->params; |
557 |
} |
558 |
} |
559 |
if (!strcmp("aio", blkdev->fileproto)) { |
560 |
blkdev->fileproto = "raw";
|
561 |
} |
562 |
if (blkdev->mode == NULL) { |
563 |
blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
|
564 |
} |
565 |
if (blkdev->type == NULL) { |
566 |
blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type");
|
567 |
} |
568 |
if (blkdev->dev == NULL) { |
569 |
blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev");
|
570 |
} |
571 |
if (blkdev->devtype == NULL) { |
572 |
blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type");
|
573 |
} |
574 |
|
575 |
/* do we have all we need? */
|
576 |
if (blkdev->params == NULL || |
577 |
blkdev->mode == NULL ||
|
578 |
blkdev->type == NULL ||
|
579 |
blkdev->dev == NULL) {
|
580 |
goto out_error;
|
581 |
} |
582 |
|
583 |
/* read-only ? */
|
584 |
if (strcmp(blkdev->mode, "w") == 0) { |
585 |
qflags = BDRV_O_RDWR; |
586 |
} else {
|
587 |
qflags = 0;
|
588 |
info |= VDISK_READONLY; |
589 |
} |
590 |
|
591 |
/* cdrom ? */
|
592 |
if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) { |
593 |
info |= VDISK_CDROM; |
594 |
} |
595 |
|
596 |
/* init qemu block driver */
|
597 |
index = (blkdev->xendev.dev - 202 * 256) / 16; |
598 |
blkdev->dinfo = drive_get(IF_XEN, 0, index);
|
599 |
if (!blkdev->dinfo) {
|
600 |
/* setup via xenbus -> create new block driver instance */
|
601 |
xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n"); |
602 |
blkdev->bs = bdrv_new(blkdev->dev); |
603 |
if (blkdev->bs) {
|
604 |
if (bdrv_open(blkdev->bs, blkdev->filename, qflags,
|
605 |
bdrv_find_whitelisted_format(blkdev->fileproto)) != 0) {
|
606 |
bdrv_delete(blkdev->bs); |
607 |
blkdev->bs = NULL;
|
608 |
} |
609 |
} |
610 |
if (!blkdev->bs) {
|
611 |
goto out_error;
|
612 |
} |
613 |
} else {
|
614 |
/* setup via qemu cmdline -> already setup for us */
|
615 |
xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n"); |
616 |
blkdev->bs = blkdev->dinfo->bdrv; |
617 |
} |
618 |
bdrv_attach_dev_nofail(blkdev->bs, blkdev); |
619 |
blkdev->file_blk = BLOCK_SIZE; |
620 |
blkdev->file_size = bdrv_getlength(blkdev->bs); |
621 |
if (blkdev->file_size < 0) { |
622 |
xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n", |
623 |
(int)blkdev->file_size, strerror(-blkdev->file_size),
|
624 |
blkdev->bs->drv ? blkdev->bs->drv->format_name : "-");
|
625 |
blkdev->file_size = 0;
|
626 |
} |
627 |
|
628 |
xen_be_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\"," |
629 |
" size %" PRId64 " (%" PRId64 " MB)\n", |
630 |
blkdev->type, blkdev->fileproto, blkdev->filename, |
631 |
blkdev->file_size, blkdev->file_size >> 20);
|
632 |
|
633 |
/* fill info */
|
634 |
xenstore_write_be_int(&blkdev->xendev, "feature-barrier", 1); |
635 |
xenstore_write_be_int(&blkdev->xendev, "info", info);
|
636 |
xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk);
|
637 |
xenstore_write_be_int(&blkdev->xendev, "sectors",
|
638 |
blkdev->file_size / blkdev->file_blk); |
639 |
return 0; |
640 |
|
641 |
out_error:
|
642 |
g_free(blkdev->params); |
643 |
blkdev->params = NULL;
|
644 |
g_free(blkdev->mode); |
645 |
blkdev->mode = NULL;
|
646 |
g_free(blkdev->type); |
647 |
blkdev->type = NULL;
|
648 |
g_free(blkdev->dev); |
649 |
blkdev->dev = NULL;
|
650 |
g_free(blkdev->devtype); |
651 |
blkdev->devtype = NULL;
|
652 |
return -1; |
653 |
} |
654 |
|
655 |
static int blk_connect(struct XenDevice *xendev) |
656 |
{ |
657 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
658 |
|
659 |
if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) { |
660 |
return -1; |
661 |
} |
662 |
if (xenstore_read_fe_int(&blkdev->xendev, "event-channel", |
663 |
&blkdev->xendev.remote_port) == -1) {
|
664 |
return -1; |
665 |
} |
666 |
|
667 |
blkdev->protocol = BLKIF_PROTOCOL_NATIVE; |
668 |
if (blkdev->xendev.protocol) {
|
669 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { |
670 |
blkdev->protocol = BLKIF_PROTOCOL_X86_32; |
671 |
} |
672 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { |
673 |
blkdev->protocol = BLKIF_PROTOCOL_X86_64; |
674 |
} |
675 |
} |
676 |
|
677 |
blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev, |
678 |
blkdev->xendev.dom, |
679 |
blkdev->ring_ref, |
680 |
PROT_READ | PROT_WRITE); |
681 |
if (!blkdev->sring) {
|
682 |
return -1; |
683 |
} |
684 |
blkdev->cnt_map++; |
685 |
|
686 |
switch (blkdev->protocol) {
|
687 |
case BLKIF_PROTOCOL_NATIVE:
|
688 |
{ |
689 |
blkif_sring_t *sring_native = blkdev->sring; |
690 |
BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_SIZE); |
691 |
break;
|
692 |
} |
693 |
case BLKIF_PROTOCOL_X86_32:
|
694 |
{ |
695 |
blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring; |
696 |
|
697 |
BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, XC_PAGE_SIZE); |
698 |
break;
|
699 |
} |
700 |
case BLKIF_PROTOCOL_X86_64:
|
701 |
{ |
702 |
blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring; |
703 |
|
704 |
BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, XC_PAGE_SIZE); |
705 |
break;
|
706 |
} |
707 |
} |
708 |
|
709 |
xen_be_bind_evtchn(&blkdev->xendev); |
710 |
|
711 |
xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " |
712 |
"remote port %d, local port %d\n",
|
713 |
blkdev->xendev.protocol, blkdev->ring_ref, |
714 |
blkdev->xendev.remote_port, blkdev->xendev.local_port); |
715 |
return 0; |
716 |
} |
717 |
|
718 |
static void blk_disconnect(struct XenDevice *xendev) |
719 |
{ |
720 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
721 |
|
722 |
if (blkdev->bs) {
|
723 |
if (!blkdev->dinfo) {
|
724 |
/* close/delete only if we created it ourself */
|
725 |
bdrv_close(blkdev->bs); |
726 |
bdrv_delete(blkdev->bs); |
727 |
} |
728 |
blkdev->bs = NULL;
|
729 |
} |
730 |
xen_be_unbind_evtchn(&blkdev->xendev); |
731 |
|
732 |
if (blkdev->sring) {
|
733 |
xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1);
|
734 |
blkdev->cnt_map--; |
735 |
blkdev->sring = NULL;
|
736 |
} |
737 |
} |
738 |
|
739 |
static int blk_free(struct XenDevice *xendev) |
740 |
{ |
741 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
742 |
struct ioreq *ioreq;
|
743 |
|
744 |
while (!QLIST_EMPTY(&blkdev->freelist)) {
|
745 |
ioreq = QLIST_FIRST(&blkdev->freelist); |
746 |
QLIST_REMOVE(ioreq, list); |
747 |
qemu_iovec_destroy(&ioreq->v); |
748 |
g_free(ioreq); |
749 |
} |
750 |
|
751 |
g_free(blkdev->params); |
752 |
g_free(blkdev->mode); |
753 |
g_free(blkdev->type); |
754 |
g_free(blkdev->dev); |
755 |
g_free(blkdev->devtype); |
756 |
qemu_bh_delete(blkdev->bh); |
757 |
return 0; |
758 |
} |
759 |
|
760 |
static void blk_event(struct XenDevice *xendev) |
761 |
{ |
762 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
763 |
|
764 |
qemu_bh_schedule(blkdev->bh); |
765 |
} |
766 |
|
767 |
struct XenDevOps xen_blkdev_ops = {
|
768 |
.size = sizeof(struct XenBlkDev), |
769 |
.flags = DEVOPS_FLAG_NEED_GNTDEV, |
770 |
.alloc = blk_alloc, |
771 |
.init = blk_init, |
772 |
.initialise = blk_connect, |
773 |
.disconnect = blk_disconnect, |
774 |
.event = blk_event, |
775 |
.free = blk_free, |
776 |
}; |