2
* xen paravirt block device backend
4
* (c) Gerd Hoffmann <kraxel@redhat.com>
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* 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
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* the Free Software Foundation; under version 2 of the License.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, see <http://www.gnu.org/licenses/>.
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
32
#include <sys/ioctl.h>
33
#include <sys/types.h>
39
#include "xen_backend.h"
40
#include "xen_blkif.h"
41
#include "sysemu/blockdev.h"
43
/* ------------------------------------------------------------- */
45
static int batch_maps = 0;
47
static int max_requests = 32;
49
/* ------------------------------------------------------------- */
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#define BLOCK_SIZE 512
52
#define IOCB_COUNT (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2)
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struct PersistentGrant {
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struct XenBlkDev *blkdev;
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typedef struct PersistentGrant PersistentGrant;
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uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
84
struct XenBlkDev *blkdev;
85
QLIST_ENTRY(ioreq) list;
90
struct XenDevice xendev; /* must be first */
96
const char *fileproto;
103
blkif_back_rings_t rings;
108
QLIST_HEAD(inflight_head, ioreq) inflight;
109
QLIST_HEAD(finished_head, ioreq) finished;
110
QLIST_HEAD(freelist_head, ioreq) freelist;
112
int requests_inflight;
113
int requests_finished;
115
/* Persistent grants extension */
116
gboolean feature_persistent;
117
GTree *persistent_gnts;
118
unsigned int persistent_gnt_count;
119
unsigned int max_grants;
121
/* qemu block driver */
123
BlockDriverState *bs;
127
/* ------------------------------------------------------------- */
129
static void ioreq_reset(struct ioreq *ioreq)
131
memset(&ioreq->req, 0, sizeof(ioreq->req));
138
memset(ioreq->domids, 0, sizeof(ioreq->domids));
139
memset(ioreq->refs, 0, sizeof(ioreq->refs));
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memset(ioreq->page, 0, sizeof(ioreq->page));
144
ioreq->aio_inflight = 0;
145
ioreq->aio_errors = 0;
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ioreq->blkdev = NULL;
148
memset(&ioreq->list, 0, sizeof(ioreq->list));
149
memset(&ioreq->acct, 0, sizeof(ioreq->acct));
151
qemu_iovec_reset(&ioreq->v);
154
static gint int_cmp(gconstpointer a, gconstpointer b, gpointer user_data)
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uint ua = GPOINTER_TO_UINT(a);
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uint ub = GPOINTER_TO_UINT(b);
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return (ua > ub) - (ua < ub);
161
static void destroy_grant(gpointer pgnt)
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PersistentGrant *grant = pgnt;
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XenGnttab gnt = grant->blkdev->xendev.gnttabdev;
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if (xc_gnttab_munmap(gnt, grant->page, 1) != 0) {
167
xen_be_printf(&grant->blkdev->xendev, 0,
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"xc_gnttab_munmap failed: %s\n",
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grant->blkdev->persistent_gnt_count--;
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xen_be_printf(&grant->blkdev->xendev, 3,
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"unmapped grant %p\n", grant->page);
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static struct ioreq *ioreq_start(struct XenBlkDev *blkdev)
179
struct ioreq *ioreq = NULL;
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if (QLIST_EMPTY(&blkdev->freelist)) {
182
if (blkdev->requests_total >= max_requests) {
185
/* allocate new struct */
186
ioreq = g_malloc0(sizeof(*ioreq));
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ioreq->blkdev = blkdev;
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blkdev->requests_total++;
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qemu_iovec_init(&ioreq->v, BLKIF_MAX_SEGMENTS_PER_REQUEST);
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/* get one from freelist */
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ioreq = QLIST_FIRST(&blkdev->freelist);
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QLIST_REMOVE(ioreq, list);
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QLIST_INSERT_HEAD(&blkdev->inflight, ioreq, list);
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blkdev->requests_inflight++;
202
static void ioreq_finish(struct ioreq *ioreq)
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struct XenBlkDev *blkdev = ioreq->blkdev;
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QLIST_REMOVE(ioreq, list);
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QLIST_INSERT_HEAD(&blkdev->finished, ioreq, list);
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blkdev->requests_inflight--;
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blkdev->requests_finished++;
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static void ioreq_release(struct ioreq *ioreq, bool finish)
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struct XenBlkDev *blkdev = ioreq->blkdev;
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QLIST_REMOVE(ioreq, list);
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ioreq->blkdev = blkdev;
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QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list);
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blkdev->requests_finished--;
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blkdev->requests_inflight--;
228
* translate request into iovec + start offset
229
* do sanity checks along the way
231
static int ioreq_parse(struct ioreq *ioreq)
233
struct XenBlkDev *blkdev = ioreq->blkdev;
238
xen_be_printf(&blkdev->xendev, 3,
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"op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n",
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ioreq->req.operation, ioreq->req.nr_segments,
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ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number);
242
switch (ioreq->req.operation) {
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ioreq->prot = PROT_WRITE; /* to memory */
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case BLKIF_OP_FLUSH_DISKCACHE:
248
if (!ioreq->req.nr_segments) {
253
ioreq->prot = PROT_READ; /* from memory */
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xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n",
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ioreq->req.operation);
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if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') {
262
xen_be_printf(&blkdev->xendev, 0, "error: write req for ro device\n");
266
ioreq->start = ioreq->req.sector_number * blkdev->file_blk;
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for (i = 0; i < ioreq->req.nr_segments; i++) {
268
if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
269
xen_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n");
272
if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) {
273
xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n");
276
if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) {
277
xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n");
281
ioreq->domids[i] = blkdev->xendev.dom;
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ioreq->refs[i] = ioreq->req.seg[i].gref;
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mem = ioreq->req.seg[i].first_sect * blkdev->file_blk;
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len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk;
286
qemu_iovec_add(&ioreq->v, (void*)mem, len);
288
if (ioreq->start + ioreq->v.size > blkdev->file_size) {
289
xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n");
295
ioreq->status = BLKIF_RSP_ERROR;
299
static void ioreq_unmap(struct ioreq *ioreq)
301
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;
304
if (ioreq->num_unmap == 0 || ioreq->mapped == 0) {
311
if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->num_unmap) != 0) {
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xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n",
315
ioreq->blkdev->cnt_map -= ioreq->num_unmap;
318
for (i = 0; i < ioreq->num_unmap; i++) {
319
if (!ioreq->page[i]) {
322
if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0) {
323
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n",
326
ioreq->blkdev->cnt_map--;
327
ioreq->page[i] = NULL;
333
static int ioreq_map(struct ioreq *ioreq)
335
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;
336
uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST];
337
uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST];
338
void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
339
int i, j, new_maps = 0;
340
PersistentGrant *grant;
341
/* domids and refs variables will contain the information necessary
342
* to map the grants that are needed to fulfill this request.
344
* After mapping the needed grants, the page array will contain the
345
* memory address of each granted page in the order specified in ioreq
346
* (disregarding if it's a persistent grant or not).
349
if (ioreq->v.niov == 0 || ioreq->mapped == 1) {
352
if (ioreq->blkdev->feature_persistent) {
353
for (i = 0; i < ioreq->v.niov; i++) {
354
grant = g_tree_lookup(ioreq->blkdev->persistent_gnts,
355
GUINT_TO_POINTER(ioreq->refs[i]));
358
page[i] = grant->page;
359
xen_be_printf(&ioreq->blkdev->xendev, 3,
360
"using persistent-grant %" PRIu32 "\n",
363
/* Add the grant to the list of grants that
366
domids[new_maps] = ioreq->domids[i];
367
refs[new_maps] = ioreq->refs[i];
372
/* Set the protection to RW, since grants may be reused later
373
* with a different protection than the one needed for this request
375
ioreq->prot = PROT_WRITE | PROT_READ;
377
/* All grants in the request should be mapped */
378
memcpy(refs, ioreq->refs, sizeof(refs));
379
memcpy(domids, ioreq->domids, sizeof(domids));
380
memset(page, 0, sizeof(page));
381
new_maps = ioreq->v.niov;
384
if (batch_maps && new_maps) {
385
ioreq->pages = xc_gnttab_map_grant_refs
386
(gnt, new_maps, domids, refs, ioreq->prot);
387
if (ioreq->pages == NULL) {
388
xen_be_printf(&ioreq->blkdev->xendev, 0,
389
"can't map %d grant refs (%s, %d maps)\n",
390
new_maps, strerror(errno), ioreq->blkdev->cnt_map);
393
for (i = 0, j = 0; i < ioreq->v.niov; i++) {
394
if (page[i] == NULL) {
395
page[i] = ioreq->pages + (j++) * XC_PAGE_SIZE;
398
ioreq->blkdev->cnt_map += new_maps;
399
} else if (new_maps) {
400
for (i = 0; i < new_maps; i++) {
401
ioreq->page[i] = xc_gnttab_map_grant_ref
402
(gnt, domids[i], refs[i], ioreq->prot);
403
if (ioreq->page[i] == NULL) {
404
xen_be_printf(&ioreq->blkdev->xendev, 0,
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"can't map grant ref %d (%s, %d maps)\n",
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refs[i], strerror(errno), ioreq->blkdev->cnt_map);
410
ioreq->blkdev->cnt_map++;
412
for (i = 0, j = 0; i < ioreq->v.niov; i++) {
413
if (page[i] == NULL) {
414
page[i] = ioreq->page[j++];
418
if (ioreq->blkdev->feature_persistent) {
419
while ((ioreq->blkdev->persistent_gnt_count < ioreq->blkdev->max_grants)
421
/* Go through the list of newly mapped grants and add as many
422
* as possible to the list of persistently mapped grants.
424
* Since we start at the end of ioreq->page(s), we only need
425
* to decrease new_maps to prevent this granted pages from
426
* being unmapped in ioreq_unmap.
428
grant = g_malloc0(sizeof(*grant));
431
grant->page = ioreq->pages + (new_maps) * XC_PAGE_SIZE;
433
grant->page = ioreq->page[new_maps];
435
grant->blkdev = ioreq->blkdev;
436
xen_be_printf(&ioreq->blkdev->xendev, 3,
437
"adding grant %" PRIu32 " page: %p\n",
438
refs[new_maps], grant->page);
439
g_tree_insert(ioreq->blkdev->persistent_gnts,
440
GUINT_TO_POINTER(refs[new_maps]),
442
ioreq->blkdev->persistent_gnt_count++;
445
for (i = 0; i < ioreq->v.niov; i++) {
446
ioreq->v.iov[i].iov_base += (uintptr_t)page[i];
449
ioreq->num_unmap = new_maps;
453
static int ioreq_runio_qemu_aio(struct ioreq *ioreq);
455
static void qemu_aio_complete(void *opaque, int ret)
457
struct ioreq *ioreq = opaque;
460
xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n",
461
ioreq->req.operation == BLKIF_OP_READ ? "read" : "write");
465
ioreq->aio_inflight--;
466
if (ioreq->presync) {
468
ioreq_runio_qemu_aio(ioreq);
471
if (ioreq->aio_inflight > 0) {
474
if (ioreq->postsync) {
476
ioreq->aio_inflight++;
477
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq);
481
ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY;
484
bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct);
485
qemu_bh_schedule(ioreq->blkdev->bh);
488
static int ioreq_runio_qemu_aio(struct ioreq *ioreq)
490
struct XenBlkDev *blkdev = ioreq->blkdev;
492
if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) {
496
ioreq->aio_inflight++;
497
if (ioreq->presync) {
498
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq);
502
switch (ioreq->req.operation) {
504
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_READ);
505
ioreq->aio_inflight++;
506
bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE,
507
&ioreq->v, ioreq->v.size / BLOCK_SIZE,
508
qemu_aio_complete, ioreq);
511
case BLKIF_OP_FLUSH_DISKCACHE:
512
if (!ioreq->req.nr_segments) {
516
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_WRITE);
517
ioreq->aio_inflight++;
518
bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE,
519
&ioreq->v, ioreq->v.size / BLOCK_SIZE,
520
qemu_aio_complete, ioreq);
523
/* unknown operation (shouldn't happen -- parse catches this) */
527
qemu_aio_complete(ioreq, 0);
535
ioreq->status = BLKIF_RSP_ERROR;
539
static int blk_send_response_one(struct ioreq *ioreq)
541
struct XenBlkDev *blkdev = ioreq->blkdev;
543
int have_requests = 0;
544
blkif_response_t resp;
547
resp.id = ioreq->req.id;
548
resp.operation = ioreq->req.operation;
549
resp.status = ioreq->status;
551
/* Place on the response ring for the relevant domain. */
552
switch (blkdev->protocol) {
553
case BLKIF_PROTOCOL_NATIVE:
554
dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt);
556
case BLKIF_PROTOCOL_X86_32:
557
dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part,
558
blkdev->rings.x86_32_part.rsp_prod_pvt);
560
case BLKIF_PROTOCOL_X86_64:
561
dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part,
562
blkdev->rings.x86_64_part.rsp_prod_pvt);
567
memcpy(dst, &resp, sizeof(resp));
568
blkdev->rings.common.rsp_prod_pvt++;
570
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify);
571
if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
573
* Tail check for pending requests. Allows frontend to avoid
574
* notifications if requests are already in flight (lower
575
* overheads and promotes batching).
577
RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests);
578
} else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) {
588
/* walk finished list, send outstanding responses, free requests */
589
static void blk_send_response_all(struct XenBlkDev *blkdev)
594
while (!QLIST_EMPTY(&blkdev->finished)) {
595
ioreq = QLIST_FIRST(&blkdev->finished);
596
send_notify += blk_send_response_one(ioreq);
597
ioreq_release(ioreq, true);
600
xen_be_send_notify(&blkdev->xendev);
604
static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc)
606
switch (blkdev->protocol) {
607
case BLKIF_PROTOCOL_NATIVE:
608
memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc),
611
case BLKIF_PROTOCOL_X86_32:
612
blkif_get_x86_32_req(&ioreq->req,
613
RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc));
615
case BLKIF_PROTOCOL_X86_64:
616
blkif_get_x86_64_req(&ioreq->req,
617
RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc));
623
static void blk_handle_requests(struct XenBlkDev *blkdev)
628
blkdev->more_work = 0;
630
rc = blkdev->rings.common.req_cons;
631
rp = blkdev->rings.common.sring->req_prod;
632
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
634
blk_send_response_all(blkdev);
636
/* pull request from ring */
637
if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
640
ioreq = ioreq_start(blkdev);
645
blk_get_request(blkdev, ioreq, rc);
646
blkdev->rings.common.req_cons = ++rc;
649
if (ioreq_parse(ioreq) != 0) {
650
if (blk_send_response_one(ioreq)) {
651
xen_be_send_notify(&blkdev->xendev);
653
ioreq_release(ioreq, false);
657
ioreq_runio_qemu_aio(ioreq);
660
if (blkdev->more_work && blkdev->requests_inflight < max_requests) {
661
qemu_bh_schedule(blkdev->bh);
665
/* ------------------------------------------------------------- */
667
static void blk_bh(void *opaque)
669
struct XenBlkDev *blkdev = opaque;
670
blk_handle_requests(blkdev);
674
* We need to account for the grant allocations requiring contiguous
675
* chunks; the worst case number would be
676
* max_req * max_seg + (max_req - 1) * (max_seg - 1) + 1,
677
* but in order to keep things simple just use
678
* 2 * max_req * max_seg.
680
#define MAX_GRANTS(max_req, max_seg) (2 * (max_req) * (max_seg))
682
static void blk_alloc(struct XenDevice *xendev)
684
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
686
QLIST_INIT(&blkdev->inflight);
687
QLIST_INIT(&blkdev->finished);
688
QLIST_INIT(&blkdev->freelist);
689
blkdev->bh = qemu_bh_new(blk_bh, blkdev);
690
if (xen_mode != XEN_EMULATE) {
693
if (xc_gnttab_set_max_grants(xendev->gnttabdev,
694
MAX_GRANTS(max_requests, BLKIF_MAX_SEGMENTS_PER_REQUEST)) < 0) {
695
xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n",
700
static int blk_init(struct XenDevice *xendev)
702
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
703
int index, qflags, info = 0;
705
/* read xenstore entries */
706
if (blkdev->params == NULL) {
708
blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params");
709
if (blkdev->params != NULL) {
710
h = strchr(blkdev->params, ':');
713
blkdev->fileproto = blkdev->params;
714
blkdev->filename = h+1;
717
blkdev->fileproto = "<unset>";
718
blkdev->filename = blkdev->params;
721
if (!strcmp("aio", blkdev->fileproto)) {
722
blkdev->fileproto = "raw";
724
if (blkdev->mode == NULL) {
725
blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
727
if (blkdev->type == NULL) {
728
blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type");
730
if (blkdev->dev == NULL) {
731
blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev");
733
if (blkdev->devtype == NULL) {
734
blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type");
737
/* do we have all we need? */
738
if (blkdev->params == NULL ||
739
blkdev->mode == NULL ||
740
blkdev->type == NULL ||
741
blkdev->dev == NULL) {
746
qflags = BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NATIVE_AIO;
747
if (strcmp(blkdev->mode, "w") == 0) {
748
qflags |= BDRV_O_RDWR;
750
info |= VDISK_READONLY;
754
if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) {
758
/* init qemu block driver */
759
index = (blkdev->xendev.dev - 202 * 256) / 16;
760
blkdev->dinfo = drive_get(IF_XEN, 0, index);
761
if (!blkdev->dinfo) {
762
/* setup via xenbus -> create new block driver instance */
763
xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n");
764
blkdev->bs = bdrv_new(blkdev->dev);
766
if (bdrv_open(blkdev->bs, blkdev->filename, qflags,
767
bdrv_find_whitelisted_format(blkdev->fileproto)) != 0) {
768
bdrv_delete(blkdev->bs);
776
/* setup via qemu cmdline -> already setup for us */
777
xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n");
778
blkdev->bs = blkdev->dinfo->bdrv;
780
bdrv_attach_dev_nofail(blkdev->bs, blkdev);
781
blkdev->file_blk = BLOCK_SIZE;
782
blkdev->file_size = bdrv_getlength(blkdev->bs);
783
if (blkdev->file_size < 0) {
784
xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n",
785
(int)blkdev->file_size, strerror(-blkdev->file_size),
786
bdrv_get_format_name(blkdev->bs) ?: "-");
787
blkdev->file_size = 0;
790
xen_be_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\","
791
" size %" PRId64 " (%" PRId64 " MB)\n",
792
blkdev->type, blkdev->fileproto, blkdev->filename,
793
blkdev->file_size, blkdev->file_size >> 20);
796
xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1);
797
xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1);
798
xenstore_write_be_int(&blkdev->xendev, "info", info);
799
xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk);
800
xenstore_write_be_int(&blkdev->xendev, "sectors",
801
blkdev->file_size / blkdev->file_blk);
805
g_free(blkdev->params);
806
blkdev->params = NULL;
807
g_free(blkdev->mode);
809
g_free(blkdev->type);
813
g_free(blkdev->devtype);
814
blkdev->devtype = NULL;
818
static int blk_connect(struct XenDevice *xendev)
820
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
823
if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) {
826
if (xenstore_read_fe_int(&blkdev->xendev, "event-channel",
827
&blkdev->xendev.remote_port) == -1) {
830
if (xenstore_read_fe_int(&blkdev->xendev, "feature-persistent", &pers)) {
831
blkdev->feature_persistent = FALSE;
833
blkdev->feature_persistent = !!pers;
836
blkdev->protocol = BLKIF_PROTOCOL_NATIVE;
837
if (blkdev->xendev.protocol) {
838
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) {
839
blkdev->protocol = BLKIF_PROTOCOL_X86_32;
841
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) {
842
blkdev->protocol = BLKIF_PROTOCOL_X86_64;
846
blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev,
849
PROT_READ | PROT_WRITE);
850
if (!blkdev->sring) {
855
switch (blkdev->protocol) {
856
case BLKIF_PROTOCOL_NATIVE:
858
blkif_sring_t *sring_native = blkdev->sring;
859
BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_SIZE);
862
case BLKIF_PROTOCOL_X86_32:
864
blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring;
866
BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, XC_PAGE_SIZE);
869
case BLKIF_PROTOCOL_X86_64:
871
blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring;
873
BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, XC_PAGE_SIZE);
878
if (blkdev->feature_persistent) {
879
/* Init persistent grants */
880
blkdev->max_grants = max_requests * BLKIF_MAX_SEGMENTS_PER_REQUEST;
881
blkdev->persistent_gnts = g_tree_new_full((GCompareDataFunc)int_cmp,
883
(GDestroyNotify)destroy_grant);
884
blkdev->persistent_gnt_count = 0;
887
xen_be_bind_evtchn(&blkdev->xendev);
889
xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, "
890
"remote port %d, local port %d\n",
891
blkdev->xendev.protocol, blkdev->ring_ref,
892
blkdev->xendev.remote_port, blkdev->xendev.local_port);
896
static void blk_disconnect(struct XenDevice *xendev)
898
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
901
if (!blkdev->dinfo) {
902
/* close/delete only if we created it ourself */
903
bdrv_close(blkdev->bs);
904
bdrv_detach_dev(blkdev->bs, blkdev);
905
bdrv_delete(blkdev->bs);
909
xen_be_unbind_evtchn(&blkdev->xendev);
912
xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1);
914
blkdev->sring = NULL;
918
static int blk_free(struct XenDevice *xendev)
920
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
923
if (blkdev->bs || blkdev->sring) {
924
blk_disconnect(xendev);
927
/* Free persistent grants */
928
if (blkdev->feature_persistent) {
929
g_tree_destroy(blkdev->persistent_gnts);
932
while (!QLIST_EMPTY(&blkdev->freelist)) {
933
ioreq = QLIST_FIRST(&blkdev->freelist);
934
QLIST_REMOVE(ioreq, list);
935
qemu_iovec_destroy(&ioreq->v);
939
g_free(blkdev->params);
940
g_free(blkdev->mode);
941
g_free(blkdev->type);
943
g_free(blkdev->devtype);
944
qemu_bh_delete(blkdev->bh);
948
static void blk_event(struct XenDevice *xendev)
950
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
952
qemu_bh_schedule(blkdev->bh);
955
struct XenDevOps xen_blkdev_ops = {
956
.size = sizeof(struct XenBlkDev),
957
.flags = DEVOPS_FLAG_NEED_GNTDEV,
960
.initialise = blk_connect,
961
.disconnect = blk_disconnect,