root / hw / xen_disk.c @ bf3bc4c4
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/*
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* xen paravirt block device backend
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*
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* (c) Gerd Hoffmann <kraxel@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* 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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*
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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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*
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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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*
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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.
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*/
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#include <stdio.h> |
| 23 |
#include <stdlib.h> |
| 24 |
#include <stdarg.h> |
| 25 |
#include <string.h> |
| 26 |
#include <unistd.h> |
| 27 |
#include <signal.h> |
| 28 |
#include <inttypes.h> |
| 29 |
#include <time.h> |
| 30 |
#include <fcntl.h> |
| 31 |
#include <errno.h> |
| 32 |
#include <sys/ioctl.h> |
| 33 |
#include <sys/types.h> |
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#include <sys/stat.h> |
| 35 |
#include <sys/mman.h> |
| 36 |
#include <sys/uio.h> |
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|
| 38 |
#include "hw.h" |
| 39 |
#include "qemu-char.h" |
| 40 |
#include "xen_backend.h" |
| 41 |
#include "xen_blkif.h" |
| 42 |
#include "blockdev.h" |
| 43 |
|
| 44 |
/* ------------------------------------------------------------- */
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|
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static int batch_maps = 0; |
| 47 |
|
| 48 |
static int max_requests = 32; |
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|
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/* ------------------------------------------------------------- */
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|
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#define BLOCK_SIZE 512 |
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#define IOCB_COUNT (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2) |
| 54 |
|
| 55 |
struct ioreq {
|
| 56 |
blkif_request_t req; |
| 57 |
int16_t status; |
| 58 |
|
| 59 |
/* parsed request */
|
| 60 |
off_t start; |
| 61 |
QEMUIOVector v; |
| 62 |
int presync;
|
| 63 |
int postsync;
|
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uint8_t mapped; |
| 65 |
|
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/* grant mapping */
|
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uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
| 68 |
uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
| 69 |
int prot;
|
| 70 |
void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
|
| 71 |
void *pages;
|
| 72 |
|
| 73 |
/* aio status */
|
| 74 |
int aio_inflight;
|
| 75 |
int aio_errors;
|
| 76 |
|
| 77 |
struct XenBlkDev *blkdev;
|
| 78 |
QLIST_ENTRY(ioreq) list; |
| 79 |
BlockAcctCookie acct; |
| 80 |
}; |
| 81 |
|
| 82 |
struct XenBlkDev {
|
| 83 |
struct XenDevice xendev; /* must be first */ |
| 84 |
char *params;
|
| 85 |
char *mode;
|
| 86 |
char *type;
|
| 87 |
char *dev;
|
| 88 |
char *devtype;
|
| 89 |
const char *fileproto; |
| 90 |
const char *filename; |
| 91 |
int ring_ref;
|
| 92 |
void *sring;
|
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int64_t file_blk; |
| 94 |
int64_t file_size; |
| 95 |
int protocol;
|
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blkif_back_rings_t rings; |
| 97 |
int more_work;
|
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int cnt_map;
|
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|
| 100 |
/* request lists */
|
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QLIST_HEAD(inflight_head, ioreq) inflight; |
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QLIST_HEAD(finished_head, ioreq) finished; |
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QLIST_HEAD(freelist_head, ioreq) freelist; |
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int requests_total;
|
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int requests_inflight;
|
| 106 |
int requests_finished;
|
| 107 |
|
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/* qemu block driver */
|
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DriveInfo *dinfo; |
| 110 |
BlockDriverState *bs; |
| 111 |
QEMUBH *bh; |
| 112 |
}; |
| 113 |
|
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/* ------------------------------------------------------------- */
|
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|
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static struct ioreq *ioreq_start(struct XenBlkDev *blkdev) |
| 117 |
{
|
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struct ioreq *ioreq = NULL; |
| 119 |
|
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if (QLIST_EMPTY(&blkdev->freelist)) {
|
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if (blkdev->requests_total >= max_requests) {
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goto out;
|
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} |
| 124 |
/* allocate new struct */
|
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ioreq = g_malloc0(sizeof(*ioreq));
|
| 126 |
ioreq->blkdev = blkdev; |
| 127 |
blkdev->requests_total++; |
| 128 |
qemu_iovec_init(&ioreq->v, BLKIF_MAX_SEGMENTS_PER_REQUEST); |
| 129 |
} else {
|
| 130 |
/* get one from freelist */
|
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ioreq = QLIST_FIRST(&blkdev->freelist); |
| 132 |
QLIST_REMOVE(ioreq, list); |
| 133 |
qemu_iovec_reset(&ioreq->v); |
| 134 |
} |
| 135 |
QLIST_INSERT_HEAD(&blkdev->inflight, ioreq, list); |
| 136 |
blkdev->requests_inflight++; |
| 137 |
|
| 138 |
out:
|
| 139 |
return ioreq;
|
| 140 |
} |
| 141 |
|
| 142 |
static void ioreq_finish(struct ioreq *ioreq) |
| 143 |
{
|
| 144 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
| 145 |
|
| 146 |
QLIST_REMOVE(ioreq, list); |
| 147 |
QLIST_INSERT_HEAD(&blkdev->finished, ioreq, list); |
| 148 |
blkdev->requests_inflight--; |
| 149 |
blkdev->requests_finished++; |
| 150 |
} |
| 151 |
|
| 152 |
static void ioreq_release(struct ioreq *ioreq, bool finish) |
| 153 |
{
|
| 154 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
| 155 |
|
| 156 |
QLIST_REMOVE(ioreq, list); |
| 157 |
memset(ioreq, 0, sizeof(*ioreq)); |
| 158 |
ioreq->blkdev = blkdev; |
| 159 |
QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list); |
| 160 |
if (finish) {
|
| 161 |
blkdev->requests_finished--; |
| 162 |
} else {
|
| 163 |
blkdev->requests_inflight--; |
| 164 |
} |
| 165 |
} |
| 166 |
|
| 167 |
/*
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* translate request into iovec + start offset
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* do sanity checks along the way
|
| 170 |
*/
|
| 171 |
static int ioreq_parse(struct ioreq *ioreq) |
| 172 |
{
|
| 173 |
struct XenBlkDev *blkdev = ioreq->blkdev;
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| 174 |
uintptr_t mem; |
| 175 |
size_t len; |
| 176 |
int i;
|
| 177 |
|
| 178 |
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, |
| 181 |
ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number); |
| 182 |
switch (ioreq->req.operation) {
|
| 183 |
case BLKIF_OP_READ:
|
| 184 |
ioreq->prot = PROT_WRITE; /* to memory */
|
| 185 |
break;
|
| 186 |
case BLKIF_OP_WRITE_BARRIER:
|
| 187 |
if (!ioreq->req.nr_segments) {
|
| 188 |
ioreq->presync = 1;
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| 189 |
return 0; |
| 190 |
} |
| 191 |
ioreq->presync = ioreq->postsync = 1;
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/* fall through */
|
| 193 |
case BLKIF_OP_WRITE:
|
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ioreq->prot = PROT_READ; /* from memory */
|
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break;
|
| 196 |
default:
|
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xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n", |
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ioreq->req.operation); |
| 199 |
goto err;
|
| 200 |
}; |
| 201 |
|
| 202 |
if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') { |
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xen_be_printf(&blkdev->xendev, 0, "error: write req for ro device\n"); |
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goto err;
|
| 205 |
} |
| 206 |
|
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ioreq->start = ioreq->req.sector_number * blkdev->file_blk; |
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for (i = 0; i < ioreq->req.nr_segments; i++) { |
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if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
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xen_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n"); |
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goto err;
|
| 212 |
} |
| 213 |
if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) {
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xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n"); |
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goto err;
|
| 216 |
} |
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if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) {
|
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xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n"); |
| 219 |
goto err;
|
| 220 |
} |
| 221 |
|
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ioreq->domids[i] = blkdev->xendev.dom; |
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ioreq->refs[i] = ioreq->req.seg[i].gref; |
| 224 |
|
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mem = ioreq->req.seg[i].first_sect * blkdev->file_blk; |
| 226 |
len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk;
|
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qemu_iovec_add(&ioreq->v, (void*)mem, len);
|
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} |
| 229 |
if (ioreq->start + ioreq->v.size > blkdev->file_size) {
|
| 230 |
xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n"); |
| 231 |
goto err;
|
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} |
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return 0; |
| 234 |
|
| 235 |
err:
|
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ioreq->status = BLKIF_RSP_ERROR; |
| 237 |
return -1; |
| 238 |
} |
| 239 |
|
| 240 |
static void ioreq_unmap(struct ioreq *ioreq) |
| 241 |
{
|
| 242 |
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
| 243 |
int i;
|
| 244 |
|
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if (ioreq->v.niov == 0 || ioreq->mapped == 0) { |
| 246 |
return;
|
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} |
| 248 |
if (batch_maps) {
|
| 249 |
if (!ioreq->pages) {
|
| 250 |
return;
|
| 251 |
} |
| 252 |
if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->v.niov) != 0) { |
| 253 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
| 254 |
strerror(errno)); |
| 255 |
} |
| 256 |
ioreq->blkdev->cnt_map -= ioreq->v.niov; |
| 257 |
ioreq->pages = NULL;
|
| 258 |
} else {
|
| 259 |
for (i = 0; i < ioreq->v.niov; i++) { |
| 260 |
if (!ioreq->page[i]) {
|
| 261 |
continue;
|
| 262 |
} |
| 263 |
if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0) { |
| 264 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
| 265 |
strerror(errno)); |
| 266 |
} |
| 267 |
ioreq->blkdev->cnt_map--; |
| 268 |
ioreq->page[i] = NULL;
|
| 269 |
} |
| 270 |
} |
| 271 |
ioreq->mapped = 0;
|
| 272 |
} |
| 273 |
|
| 274 |
static int ioreq_map(struct ioreq *ioreq) |
| 275 |
{
|
| 276 |
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
| 277 |
int i;
|
| 278 |
|
| 279 |
if (ioreq->v.niov == 0 || ioreq->mapped == 1) { |
| 280 |
return 0; |
| 281 |
} |
| 282 |
if (batch_maps) {
|
| 283 |
ioreq->pages = xc_gnttab_map_grant_refs |
| 284 |
(gnt, ioreq->v.niov, ioreq->domids, ioreq->refs, ioreq->prot); |
| 285 |
if (ioreq->pages == NULL) { |
| 286 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
|
| 287 |
"can't map %d grant refs (%s, %d maps)\n",
|
| 288 |
ioreq->v.niov, strerror(errno), ioreq->blkdev->cnt_map); |
| 289 |
return -1; |
| 290 |
} |
| 291 |
for (i = 0; i < ioreq->v.niov; i++) { |
| 292 |
ioreq->v.iov[i].iov_base = ioreq->pages + i * XC_PAGE_SIZE + |
| 293 |
(uintptr_t)ioreq->v.iov[i].iov_base; |
| 294 |
} |
| 295 |
ioreq->blkdev->cnt_map += ioreq->v.niov; |
| 296 |
} else {
|
| 297 |
for (i = 0; i < ioreq->v.niov; i++) { |
| 298 |
ioreq->page[i] = xc_gnttab_map_grant_ref |
| 299 |
(gnt, ioreq->domids[i], ioreq->refs[i], ioreq->prot); |
| 300 |
if (ioreq->page[i] == NULL) { |
| 301 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
|
| 302 |
"can't map grant ref %d (%s, %d maps)\n",
|
| 303 |
ioreq->refs[i], strerror(errno), ioreq->blkdev->cnt_map); |
| 304 |
ioreq_unmap(ioreq); |
| 305 |
return -1; |
| 306 |
} |
| 307 |
ioreq->v.iov[i].iov_base = ioreq->page[i] + (uintptr_t)ioreq->v.iov[i].iov_base; |
| 308 |
ioreq->blkdev->cnt_map++; |
| 309 |
} |
| 310 |
} |
| 311 |
ioreq->mapped = 1;
|
| 312 |
return 0; |
| 313 |
} |
| 314 |
|
| 315 |
static int ioreq_runio_qemu_aio(struct ioreq *ioreq); |
| 316 |
|
| 317 |
static void qemu_aio_complete(void *opaque, int ret) |
| 318 |
{
|
| 319 |
struct ioreq *ioreq = opaque;
|
| 320 |
|
| 321 |
if (ret != 0) { |
| 322 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n", |
| 323 |
ioreq->req.operation == BLKIF_OP_READ ? "read" : "write"); |
| 324 |
ioreq->aio_errors++; |
| 325 |
} |
| 326 |
|
| 327 |
ioreq->aio_inflight--; |
| 328 |
if (ioreq->presync) {
|
| 329 |
ioreq->presync = 0;
|
| 330 |
ioreq_runio_qemu_aio(ioreq); |
| 331 |
return;
|
| 332 |
} |
| 333 |
if (ioreq->aio_inflight > 0) { |
| 334 |
return;
|
| 335 |
} |
| 336 |
if (ioreq->postsync) {
|
| 337 |
ioreq->postsync = 0;
|
| 338 |
ioreq->aio_inflight++; |
| 339 |
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq); |
| 340 |
return;
|
| 341 |
} |
| 342 |
|
| 343 |
ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY; |
| 344 |
ioreq_unmap(ioreq); |
| 345 |
ioreq_finish(ioreq); |
| 346 |
bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct); |
| 347 |
qemu_bh_schedule(ioreq->blkdev->bh); |
| 348 |
} |
| 349 |
|
| 350 |
static int ioreq_runio_qemu_aio(struct ioreq *ioreq) |
| 351 |
{
|
| 352 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
| 353 |
|
| 354 |
if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) { |
| 355 |
goto err_no_map;
|
| 356 |
} |
| 357 |
|
| 358 |
ioreq->aio_inflight++; |
| 359 |
if (ioreq->presync) {
|
| 360 |
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq); |
| 361 |
return 0; |
| 362 |
} |
| 363 |
|
| 364 |
switch (ioreq->req.operation) {
|
| 365 |
case BLKIF_OP_READ:
|
| 366 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_READ); |
| 367 |
ioreq->aio_inflight++; |
| 368 |
bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE, |
| 369 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
| 370 |
qemu_aio_complete, ioreq); |
| 371 |
break;
|
| 372 |
case BLKIF_OP_WRITE:
|
| 373 |
case BLKIF_OP_WRITE_BARRIER:
|
| 374 |
if (!ioreq->req.nr_segments) {
|
| 375 |
break;
|
| 376 |
} |
| 377 |
|
| 378 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_WRITE); |
| 379 |
ioreq->aio_inflight++; |
| 380 |
bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE, |
| 381 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
| 382 |
qemu_aio_complete, ioreq); |
| 383 |
break;
|
| 384 |
default:
|
| 385 |
/* unknown operation (shouldn't happen -- parse catches this) */
|
| 386 |
goto err;
|
| 387 |
} |
| 388 |
|
| 389 |
qemu_aio_complete(ioreq, 0);
|
| 390 |
|
| 391 |
return 0; |
| 392 |
|
| 393 |
err:
|
| 394 |
ioreq_unmap(ioreq); |
| 395 |
err_no_map:
|
| 396 |
ioreq_finish(ioreq); |
| 397 |
ioreq->status = BLKIF_RSP_ERROR; |
| 398 |
return -1; |
| 399 |
} |
| 400 |
|
| 401 |
static int blk_send_response_one(struct ioreq *ioreq) |
| 402 |
{
|
| 403 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
| 404 |
int send_notify = 0; |
| 405 |
int have_requests = 0; |
| 406 |
blkif_response_t resp; |
| 407 |
void *dst;
|
| 408 |
|
| 409 |
resp.id = ioreq->req.id; |
| 410 |
resp.operation = ioreq->req.operation; |
| 411 |
resp.status = ioreq->status; |
| 412 |
|
| 413 |
/* Place on the response ring for the relevant domain. */
|
| 414 |
switch (blkdev->protocol) {
|
| 415 |
case BLKIF_PROTOCOL_NATIVE:
|
| 416 |
dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt); |
| 417 |
break;
|
| 418 |
case BLKIF_PROTOCOL_X86_32:
|
| 419 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part, |
| 420 |
blkdev->rings.x86_32_part.rsp_prod_pvt); |
| 421 |
break;
|
| 422 |
case BLKIF_PROTOCOL_X86_64:
|
| 423 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part, |
| 424 |
blkdev->rings.x86_64_part.rsp_prod_pvt); |
| 425 |
break;
|
| 426 |
default:
|
| 427 |
dst = NULL;
|
| 428 |
} |
| 429 |
memcpy(dst, &resp, sizeof(resp));
|
| 430 |
blkdev->rings.common.rsp_prod_pvt++; |
| 431 |
|
| 432 |
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify); |
| 433 |
if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
|
| 434 |
/*
|
| 435 |
* Tail check for pending requests. Allows frontend to avoid
|
| 436 |
* notifications if requests are already in flight (lower
|
| 437 |
* overheads and promotes batching).
|
| 438 |
*/
|
| 439 |
RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests); |
| 440 |
} else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) { |
| 441 |
have_requests = 1;
|
| 442 |
} |
| 443 |
|
| 444 |
if (have_requests) {
|
| 445 |
blkdev->more_work++; |
| 446 |
} |
| 447 |
return send_notify;
|
| 448 |
} |
| 449 |
|
| 450 |
/* walk finished list, send outstanding responses, free requests */
|
| 451 |
static void blk_send_response_all(struct XenBlkDev *blkdev) |
| 452 |
{
|
| 453 |
struct ioreq *ioreq;
|
| 454 |
int send_notify = 0; |
| 455 |
|
| 456 |
while (!QLIST_EMPTY(&blkdev->finished)) {
|
| 457 |
ioreq = QLIST_FIRST(&blkdev->finished); |
| 458 |
send_notify += blk_send_response_one(ioreq); |
| 459 |
ioreq_release(ioreq, true);
|
| 460 |
} |
| 461 |
if (send_notify) {
|
| 462 |
xen_be_send_notify(&blkdev->xendev); |
| 463 |
} |
| 464 |
} |
| 465 |
|
| 466 |
static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc) |
| 467 |
{
|
| 468 |
switch (blkdev->protocol) {
|
| 469 |
case BLKIF_PROTOCOL_NATIVE:
|
| 470 |
memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc), |
| 471 |
sizeof(ioreq->req));
|
| 472 |
break;
|
| 473 |
case BLKIF_PROTOCOL_X86_32:
|
| 474 |
blkif_get_x86_32_req(&ioreq->req, |
| 475 |
RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc)); |
| 476 |
break;
|
| 477 |
case BLKIF_PROTOCOL_X86_64:
|
| 478 |
blkif_get_x86_64_req(&ioreq->req, |
| 479 |
RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc)); |
| 480 |
break;
|
| 481 |
} |
| 482 |
return 0; |
| 483 |
} |
| 484 |
|
| 485 |
static void blk_handle_requests(struct XenBlkDev *blkdev) |
| 486 |
{
|
| 487 |
RING_IDX rc, rp; |
| 488 |
struct ioreq *ioreq;
|
| 489 |
|
| 490 |
blkdev->more_work = 0;
|
| 491 |
|
| 492 |
rc = blkdev->rings.common.req_cons; |
| 493 |
rp = blkdev->rings.common.sring->req_prod; |
| 494 |
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
|
| 495 |
|
| 496 |
blk_send_response_all(blkdev); |
| 497 |
while (rc != rp) {
|
| 498 |
/* pull request from ring */
|
| 499 |
if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
|
| 500 |
break;
|
| 501 |
} |
| 502 |
ioreq = ioreq_start(blkdev); |
| 503 |
if (ioreq == NULL) { |
| 504 |
blkdev->more_work++; |
| 505 |
break;
|
| 506 |
} |
| 507 |
blk_get_request(blkdev, ioreq, rc); |
| 508 |
blkdev->rings.common.req_cons = ++rc; |
| 509 |
|
| 510 |
/* parse them */
|
| 511 |
if (ioreq_parse(ioreq) != 0) { |
| 512 |
if (blk_send_response_one(ioreq)) {
|
| 513 |
xen_be_send_notify(&blkdev->xendev); |
| 514 |
} |
| 515 |
ioreq_release(ioreq, false);
|
| 516 |
continue;
|
| 517 |
} |
| 518 |
|
| 519 |
ioreq_runio_qemu_aio(ioreq); |
| 520 |
} |
| 521 |
|
| 522 |
if (blkdev->more_work && blkdev->requests_inflight < max_requests) {
|
| 523 |
qemu_bh_schedule(blkdev->bh); |
| 524 |
} |
| 525 |
} |
| 526 |
|
| 527 |
/* ------------------------------------------------------------- */
|
| 528 |
|
| 529 |
static void blk_bh(void *opaque) |
| 530 |
{
|
| 531 |
struct XenBlkDev *blkdev = opaque;
|
| 532 |
blk_handle_requests(blkdev); |
| 533 |
} |
| 534 |
|
| 535 |
/*
|
| 536 |
* We need to account for the grant allocations requiring contiguous
|
| 537 |
* chunks; the worst case number would be
|
| 538 |
* max_req * max_seg + (max_req - 1) * (max_seg - 1) + 1,
|
| 539 |
* but in order to keep things simple just use
|
| 540 |
* 2 * max_req * max_seg.
|
| 541 |
*/
|
| 542 |
#define MAX_GRANTS(max_req, max_seg) (2 * (max_req) * (max_seg)) |
| 543 |
|
| 544 |
static void blk_alloc(struct XenDevice *xendev) |
| 545 |
{
|
| 546 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| 547 |
|
| 548 |
QLIST_INIT(&blkdev->inflight); |
| 549 |
QLIST_INIT(&blkdev->finished); |
| 550 |
QLIST_INIT(&blkdev->freelist); |
| 551 |
blkdev->bh = qemu_bh_new(blk_bh, blkdev); |
| 552 |
if (xen_mode != XEN_EMULATE) {
|
| 553 |
batch_maps = 1;
|
| 554 |
} |
| 555 |
if (xc_gnttab_set_max_grants(xendev->gnttabdev,
|
| 556 |
MAX_GRANTS(max_requests, BLKIF_MAX_SEGMENTS_PER_REQUEST)) < 0) {
|
| 557 |
xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n", |
| 558 |
strerror(errno)); |
| 559 |
} |
| 560 |
} |
| 561 |
|
| 562 |
static int blk_init(struct XenDevice *xendev) |
| 563 |
{
|
| 564 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| 565 |
int index, qflags, info = 0; |
| 566 |
|
| 567 |
/* read xenstore entries */
|
| 568 |
if (blkdev->params == NULL) { |
| 569 |
char *h = NULL; |
| 570 |
blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params");
|
| 571 |
if (blkdev->params != NULL) { |
| 572 |
h = strchr(blkdev->params, ':');
|
| 573 |
} |
| 574 |
if (h != NULL) { |
| 575 |
blkdev->fileproto = blkdev->params; |
| 576 |
blkdev->filename = h+1;
|
| 577 |
*h = 0;
|
| 578 |
} else {
|
| 579 |
blkdev->fileproto = "<unset>";
|
| 580 |
blkdev->filename = blkdev->params; |
| 581 |
} |
| 582 |
} |
| 583 |
if (!strcmp("aio", blkdev->fileproto)) { |
| 584 |
blkdev->fileproto = "raw";
|
| 585 |
} |
| 586 |
if (blkdev->mode == NULL) { |
| 587 |
blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
|
| 588 |
} |
| 589 |
if (blkdev->type == NULL) { |
| 590 |
blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type");
|
| 591 |
} |
| 592 |
if (blkdev->dev == NULL) { |
| 593 |
blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev");
|
| 594 |
} |
| 595 |
if (blkdev->devtype == NULL) { |
| 596 |
blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type");
|
| 597 |
} |
| 598 |
|
| 599 |
/* do we have all we need? */
|
| 600 |
if (blkdev->params == NULL || |
| 601 |
blkdev->mode == NULL ||
|
| 602 |
blkdev->type == NULL ||
|
| 603 |
blkdev->dev == NULL) {
|
| 604 |
goto out_error;
|
| 605 |
} |
| 606 |
|
| 607 |
/* read-only ? */
|
| 608 |
qflags = BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NATIVE_AIO; |
| 609 |
if (strcmp(blkdev->mode, "w") == 0) { |
| 610 |
qflags |= BDRV_O_RDWR; |
| 611 |
} else {
|
| 612 |
info |= VDISK_READONLY; |
| 613 |
} |
| 614 |
|
| 615 |
/* cdrom ? */
|
| 616 |
if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) { |
| 617 |
info |= VDISK_CDROM; |
| 618 |
} |
| 619 |
|
| 620 |
/* init qemu block driver */
|
| 621 |
index = (blkdev->xendev.dev - 202 * 256) / 16; |
| 622 |
blkdev->dinfo = drive_get(IF_XEN, 0, index);
|
| 623 |
if (!blkdev->dinfo) {
|
| 624 |
/* setup via xenbus -> create new block driver instance */
|
| 625 |
xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n"); |
| 626 |
blkdev->bs = bdrv_new(blkdev->dev); |
| 627 |
if (blkdev->bs) {
|
| 628 |
if (bdrv_open(blkdev->bs, blkdev->filename, qflags,
|
| 629 |
bdrv_find_whitelisted_format(blkdev->fileproto)) != 0) {
|
| 630 |
bdrv_delete(blkdev->bs); |
| 631 |
blkdev->bs = NULL;
|
| 632 |
} |
| 633 |
} |
| 634 |
if (!blkdev->bs) {
|
| 635 |
goto out_error;
|
| 636 |
} |
| 637 |
} else {
|
| 638 |
/* setup via qemu cmdline -> already setup for us */
|
| 639 |
xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n"); |
| 640 |
blkdev->bs = blkdev->dinfo->bdrv; |
| 641 |
} |
| 642 |
bdrv_attach_dev_nofail(blkdev->bs, blkdev); |
| 643 |
blkdev->file_blk = BLOCK_SIZE; |
| 644 |
blkdev->file_size = bdrv_getlength(blkdev->bs); |
| 645 |
if (blkdev->file_size < 0) { |
| 646 |
xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n", |
| 647 |
(int)blkdev->file_size, strerror(-blkdev->file_size),
|
| 648 |
bdrv_get_format_name(blkdev->bs) ?: "-");
|
| 649 |
blkdev->file_size = 0;
|
| 650 |
} |
| 651 |
|
| 652 |
xen_be_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\"," |
| 653 |
" size %" PRId64 " (%" PRId64 " MB)\n", |
| 654 |
blkdev->type, blkdev->fileproto, blkdev->filename, |
| 655 |
blkdev->file_size, blkdev->file_size >> 20);
|
| 656 |
|
| 657 |
/* fill info */
|
| 658 |
xenstore_write_be_int(&blkdev->xendev, "feature-barrier", 1); |
| 659 |
xenstore_write_be_int(&blkdev->xendev, "info", info);
|
| 660 |
xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk);
|
| 661 |
xenstore_write_be_int(&blkdev->xendev, "sectors",
|
| 662 |
blkdev->file_size / blkdev->file_blk); |
| 663 |
return 0; |
| 664 |
|
| 665 |
out_error:
|
| 666 |
g_free(blkdev->params); |
| 667 |
blkdev->params = NULL;
|
| 668 |
g_free(blkdev->mode); |
| 669 |
blkdev->mode = NULL;
|
| 670 |
g_free(blkdev->type); |
| 671 |
blkdev->type = NULL;
|
| 672 |
g_free(blkdev->dev); |
| 673 |
blkdev->dev = NULL;
|
| 674 |
g_free(blkdev->devtype); |
| 675 |
blkdev->devtype = NULL;
|
| 676 |
return -1; |
| 677 |
} |
| 678 |
|
| 679 |
static int blk_connect(struct XenDevice *xendev) |
| 680 |
{
|
| 681 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| 682 |
|
| 683 |
if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) { |
| 684 |
return -1; |
| 685 |
} |
| 686 |
if (xenstore_read_fe_int(&blkdev->xendev, "event-channel", |
| 687 |
&blkdev->xendev.remote_port) == -1) {
|
| 688 |
return -1; |
| 689 |
} |
| 690 |
|
| 691 |
blkdev->protocol = BLKIF_PROTOCOL_NATIVE; |
| 692 |
if (blkdev->xendev.protocol) {
|
| 693 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { |
| 694 |
blkdev->protocol = BLKIF_PROTOCOL_X86_32; |
| 695 |
} |
| 696 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { |
| 697 |
blkdev->protocol = BLKIF_PROTOCOL_X86_64; |
| 698 |
} |
| 699 |
} |
| 700 |
|
| 701 |
blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev, |
| 702 |
blkdev->xendev.dom, |
| 703 |
blkdev->ring_ref, |
| 704 |
PROT_READ | PROT_WRITE); |
| 705 |
if (!blkdev->sring) {
|
| 706 |
return -1; |
| 707 |
} |
| 708 |
blkdev->cnt_map++; |
| 709 |
|
| 710 |
switch (blkdev->protocol) {
|
| 711 |
case BLKIF_PROTOCOL_NATIVE:
|
| 712 |
{
|
| 713 |
blkif_sring_t *sring_native = blkdev->sring; |
| 714 |
BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_SIZE); |
| 715 |
break;
|
| 716 |
} |
| 717 |
case BLKIF_PROTOCOL_X86_32:
|
| 718 |
{
|
| 719 |
blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring; |
| 720 |
|
| 721 |
BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, XC_PAGE_SIZE); |
| 722 |
break;
|
| 723 |
} |
| 724 |
case BLKIF_PROTOCOL_X86_64:
|
| 725 |
{
|
| 726 |
blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring; |
| 727 |
|
| 728 |
BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, XC_PAGE_SIZE); |
| 729 |
break;
|
| 730 |
} |
| 731 |
} |
| 732 |
|
| 733 |
xen_be_bind_evtchn(&blkdev->xendev); |
| 734 |
|
| 735 |
xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " |
| 736 |
"remote port %d, local port %d\n",
|
| 737 |
blkdev->xendev.protocol, blkdev->ring_ref, |
| 738 |
blkdev->xendev.remote_port, blkdev->xendev.local_port); |
| 739 |
return 0; |
| 740 |
} |
| 741 |
|
| 742 |
static void blk_disconnect(struct XenDevice *xendev) |
| 743 |
{
|
| 744 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| 745 |
|
| 746 |
if (blkdev->bs) {
|
| 747 |
if (!blkdev->dinfo) {
|
| 748 |
/* close/delete only if we created it ourself */
|
| 749 |
bdrv_close(blkdev->bs); |
| 750 |
bdrv_detach_dev(blkdev->bs, blkdev); |
| 751 |
bdrv_delete(blkdev->bs); |
| 752 |
} |
| 753 |
blkdev->bs = NULL;
|
| 754 |
} |
| 755 |
xen_be_unbind_evtchn(&blkdev->xendev); |
| 756 |
|
| 757 |
if (blkdev->sring) {
|
| 758 |
xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1);
|
| 759 |
blkdev->cnt_map--; |
| 760 |
blkdev->sring = NULL;
|
| 761 |
} |
| 762 |
} |
| 763 |
|
| 764 |
static int blk_free(struct XenDevice *xendev) |
| 765 |
{
|
| 766 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| 767 |
struct ioreq *ioreq;
|
| 768 |
|
| 769 |
if (blkdev->bs || blkdev->sring) {
|
| 770 |
blk_disconnect(xendev); |
| 771 |
} |
| 772 |
|
| 773 |
while (!QLIST_EMPTY(&blkdev->freelist)) {
|
| 774 |
ioreq = QLIST_FIRST(&blkdev->freelist); |
| 775 |
QLIST_REMOVE(ioreq, list); |
| 776 |
qemu_iovec_destroy(&ioreq->v); |
| 777 |
g_free(ioreq); |
| 778 |
} |
| 779 |
|
| 780 |
g_free(blkdev->params); |
| 781 |
g_free(blkdev->mode); |
| 782 |
g_free(blkdev->type); |
| 783 |
g_free(blkdev->dev); |
| 784 |
g_free(blkdev->devtype); |
| 785 |
qemu_bh_delete(blkdev->bh); |
| 786 |
return 0; |
| 787 |
} |
| 788 |
|
| 789 |
static void blk_event(struct XenDevice *xendev) |
| 790 |
{
|
| 791 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| 792 |
|
| 793 |
qemu_bh_schedule(blkdev->bh); |
| 794 |
} |
| 795 |
|
| 796 |
struct XenDevOps xen_blkdev_ops = {
|
| 797 |
.size = sizeof(struct XenBlkDev), |
| 798 |
.flags = DEVOPS_FLAG_NEED_GNTDEV, |
| 799 |
.alloc = blk_alloc, |
| 800 |
.init = blk_init, |
| 801 |
.initialise = blk_connect, |
| 802 |
.disconnect = blk_disconnect, |
| 803 |
.event = blk_event, |
| 804 |
.free = blk_free, |
| 805 |
}; |