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qemu/hw/block/xen_disk.c
Paul Durrant 443c3c9cf1 xen_disk: be consistent with use of xendev and blkdev->xendev 
Certain functions in xen_disk are called with a pointer to xendev
(struct XenDevice *). They then use container_of() to acces the surrounding
blkdev (struct XenBlkDev) but then in various places use &blkdev->xendev
when use of the original xendev pointer is shorter to express and clearly
equivalent.

This patch is a purely cosmetic patch which makes sure there is a xendev
pointer on stack for any function where the pointer is need on multiple
occasions modified those functions to use it consistently.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2018-05-22 11:43:22 -07:00

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/*
* xen paravirt block device backend
*
* (c) Gerd Hoffmann <kraxel@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; under version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include <sys/ioctl.h>
#include <sys/uio.h>
#include "hw/hw.h"
#include "hw/xen/xen_backend.h"
#include "xen_blkif.h"
#include "sysemu/blockdev.h"
#include "sysemu/iothread.h"
#include "sysemu/block-backend.h"
#include "qapi/error.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "trace.h"
/* ------------------------------------------------------------- */
#define BLOCK_SIZE 512
#define IOCB_COUNT (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2)
struct ioreq {
blkif_request_t req;
int16_t status;
/* parsed request */
off_t start;
QEMUIOVector v;
void *buf;
size_t size;
int presync;
/* aio status */
int aio_inflight;
int aio_errors;
struct XenBlkDev *blkdev;
QLIST_ENTRY(ioreq) list;
BlockAcctCookie acct;
};
#define MAX_RING_PAGE_ORDER 4
struct XenBlkDev {
struct XenDevice xendev; /* must be first */
char *params;
char *mode;
char *type;
char *dev;
char *devtype;
bool directiosafe;
const char *fileproto;
const char *filename;
unsigned int ring_ref[1 << MAX_RING_PAGE_ORDER];
unsigned int nr_ring_ref;
void *sring;
int64_t file_blk;
int64_t file_size;
int protocol;
blkif_back_rings_t rings;
int more_work;
/* request lists */
QLIST_HEAD(inflight_head, ioreq) inflight;
QLIST_HEAD(finished_head, ioreq) finished;
QLIST_HEAD(freelist_head, ioreq) freelist;
int requests_total;
int requests_inflight;
int requests_finished;
unsigned int max_requests;
gboolean feature_discard;
/* qemu block driver */
DriveInfo *dinfo;
BlockBackend *blk;
QEMUBH *bh;
IOThread *iothread;
AioContext *ctx;
};
/* ------------------------------------------------------------- */
static void ioreq_reset(struct ioreq *ioreq)
{
memset(&ioreq->req, 0, sizeof(ioreq->req));
ioreq->status = 0;
ioreq->start = 0;
ioreq->buf = NULL;
ioreq->size = 0;
ioreq->presync = 0;
ioreq->aio_inflight = 0;
ioreq->aio_errors = 0;
ioreq->blkdev = NULL;
memset(&ioreq->list, 0, sizeof(ioreq->list));
memset(&ioreq->acct, 0, sizeof(ioreq->acct));
qemu_iovec_reset(&ioreq->v);
}
static struct ioreq *ioreq_start(struct XenBlkDev *blkdev)
{
struct ioreq *ioreq = NULL;
if (QLIST_EMPTY(&blkdev->freelist)) {
if (blkdev->requests_total >= blkdev->max_requests) {
goto out;
}
/* allocate new struct */
ioreq = g_malloc0(sizeof(*ioreq));
ioreq->blkdev = blkdev;
blkdev->requests_total++;
qemu_iovec_init(&ioreq->v, 1);
} else {
/* get one from freelist */
ioreq = QLIST_FIRST(&blkdev->freelist);
QLIST_REMOVE(ioreq, list);
}
QLIST_INSERT_HEAD(&blkdev->inflight, ioreq, list);
blkdev->requests_inflight++;
out:
return ioreq;
}
static void ioreq_finish(struct ioreq *ioreq)
{
struct XenBlkDev *blkdev = ioreq->blkdev;
QLIST_REMOVE(ioreq, list);
QLIST_INSERT_HEAD(&blkdev->finished, ioreq, list);
blkdev->requests_inflight--;
blkdev->requests_finished++;
}
static void ioreq_release(struct ioreq *ioreq, bool finish)
{
struct XenBlkDev *blkdev = ioreq->blkdev;
QLIST_REMOVE(ioreq, list);
ioreq_reset(ioreq);
ioreq->blkdev = blkdev;
QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list);
if (finish) {
blkdev->requests_finished--;
} else {
blkdev->requests_inflight--;
}
}
/*
* translate request into iovec + start offset
* do sanity checks along the way
*/
static int ioreq_parse(struct ioreq *ioreq)
{
struct XenBlkDev *blkdev = ioreq->blkdev;
struct XenDevice *xendev = &blkdev->xendev;
size_t len;
int i;
xen_pv_printf(xendev, 3,
"op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n",
ioreq->req.operation, ioreq->req.nr_segments,
ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number);
switch (ioreq->req.operation) {
case BLKIF_OP_READ:
break;
case BLKIF_OP_FLUSH_DISKCACHE:
ioreq->presync = 1;
if (!ioreq->req.nr_segments) {
return 0;
}
/* fall through */
case BLKIF_OP_WRITE:
break;
case BLKIF_OP_DISCARD:
return 0;
default:
xen_pv_printf(xendev, 0, "error: unknown operation (%d)\n",
ioreq->req.operation);
goto err;
};
if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') {
xen_pv_printf(xendev, 0, "error: write req for ro device\n");
goto err;
}
ioreq->start = ioreq->req.sector_number * blkdev->file_blk;
for (i = 0; i < ioreq->req.nr_segments; i++) {
if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
xen_pv_printf(xendev, 0, "error: nr_segments too big\n");
goto err;
}
if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) {
xen_pv_printf(xendev, 0, "error: first > last sector\n");
goto err;
}
if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) {
xen_pv_printf(xendev, 0, "error: page crossing\n");
goto err;
}
len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk;
ioreq->size += len;
}
if (ioreq->start + ioreq->size > blkdev->file_size) {
xen_pv_printf(xendev, 0, "error: access beyond end of file\n");
goto err;
}
return 0;
err:
ioreq->status = BLKIF_RSP_ERROR;
return -1;
}
static int ioreq_grant_copy(struct ioreq *ioreq)
{
struct XenBlkDev *blkdev = ioreq->blkdev;
struct XenDevice *xendev = &blkdev->xendev;
XenGrantCopySegment segs[BLKIF_MAX_SEGMENTS_PER_REQUEST];
int i, count, rc;
int64_t file_blk = blkdev->file_blk;
bool to_domain = (ioreq->req.operation == BLKIF_OP_READ);
void *virt = ioreq->buf;
if (ioreq->req.nr_segments == 0) {
return 0;
}
count = ioreq->req.nr_segments;
for (i = 0; i < count; i++) {
if (to_domain) {
segs[i].dest.foreign.ref = ioreq->req.seg[i].gref;
segs[i].dest.foreign.offset = ioreq->req.seg[i].first_sect * file_blk;
segs[i].source.virt = virt;
} else {
segs[i].source.foreign.ref = ioreq->req.seg[i].gref;
segs[i].source.foreign.offset = ioreq->req.seg[i].first_sect * file_blk;
segs[i].dest.virt = virt;
}
segs[i].len = (ioreq->req.seg[i].last_sect
- ioreq->req.seg[i].first_sect + 1) * file_blk;
virt += segs[i].len;
}
rc = xen_be_copy_grant_refs(xendev, to_domain, segs, count);
if (rc) {
xen_pv_printf(xendev, 0,
"failed to copy data %d\n", rc);
ioreq->aio_errors++;
return -1;
}
return rc;
}
static int ioreq_runio_qemu_aio(struct ioreq *ioreq);
static void qemu_aio_complete(void *opaque, int ret)
{
struct ioreq *ioreq = opaque;
struct XenBlkDev *blkdev = ioreq->blkdev;
struct XenDevice *xendev = &blkdev->xendev;
aio_context_acquire(blkdev->ctx);
if (ret != 0) {
xen_pv_printf(xendev, 0, "%s I/O error\n",
ioreq->req.operation == BLKIF_OP_READ ? "read" : "write");
ioreq->aio_errors++;
}
ioreq->aio_inflight--;
if (ioreq->presync) {
ioreq->presync = 0;
ioreq_runio_qemu_aio(ioreq);
goto done;
}
if (ioreq->aio_inflight > 0) {
goto done;
}
switch (ioreq->req.operation) {
case BLKIF_OP_READ:
/* in case of failure ioreq->aio_errors is increased */
if (ret == 0) {
ioreq_grant_copy(ioreq);
}
qemu_vfree(ioreq->buf);
break;
case BLKIF_OP_WRITE:
case BLKIF_OP_FLUSH_DISKCACHE:
if (!ioreq->req.nr_segments) {
break;
}
qemu_vfree(ioreq->buf);
break;
default:
break;
}
ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY;
ioreq_finish(ioreq);
switch (ioreq->req.operation) {
case BLKIF_OP_WRITE:
case BLKIF_OP_FLUSH_DISKCACHE:
if (!ioreq->req.nr_segments) {
break;
}
case BLKIF_OP_READ:
if (ioreq->status == BLKIF_RSP_OKAY) {
block_acct_done(blk_get_stats(blkdev->blk), &ioreq->acct);
} else {
block_acct_failed(blk_get_stats(blkdev->blk), &ioreq->acct);
}
break;
case BLKIF_OP_DISCARD:
default:
break;
}
qemu_bh_schedule(blkdev->bh);
done:
aio_context_release(blkdev->ctx);
}
static bool blk_split_discard(struct ioreq *ioreq, blkif_sector_t sector_number,
uint64_t nr_sectors)
{
struct XenBlkDev *blkdev = ioreq->blkdev;
int64_t byte_offset;
int byte_chunk;
uint64_t byte_remaining, limit;
uint64_t sec_start = sector_number;
uint64_t sec_count = nr_sectors;
/* Wrap around, or overflowing byte limit? */
if (sec_start + sec_count < sec_count ||
sec_start + sec_count > INT64_MAX >> BDRV_SECTOR_BITS) {
return false;
}
limit = BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS;
byte_offset = sec_start << BDRV_SECTOR_BITS;
byte_remaining = sec_count << BDRV_SECTOR_BITS;
do {
byte_chunk = byte_remaining > limit ? limit : byte_remaining;
ioreq->aio_inflight++;
blk_aio_pdiscard(blkdev->blk, byte_offset, byte_chunk,
qemu_aio_complete, ioreq);
byte_remaining -= byte_chunk;
byte_offset += byte_chunk;
} while (byte_remaining > 0);
return true;
}
static int ioreq_runio_qemu_aio(struct ioreq *ioreq)
{
struct XenBlkDev *blkdev = ioreq->blkdev;
ioreq->buf = qemu_memalign(XC_PAGE_SIZE, ioreq->size);
if (ioreq->req.nr_segments &&
(ioreq->req.operation == BLKIF_OP_WRITE ||
ioreq->req.operation == BLKIF_OP_FLUSH_DISKCACHE) &&
ioreq_grant_copy(ioreq)) {
qemu_vfree(ioreq->buf);
goto err;
}
ioreq->aio_inflight++;
if (ioreq->presync) {
blk_aio_flush(ioreq->blkdev->blk, qemu_aio_complete, ioreq);
return 0;
}
switch (ioreq->req.operation) {
case BLKIF_OP_READ:
qemu_iovec_add(&ioreq->v, ioreq->buf, ioreq->size);
block_acct_start(blk_get_stats(blkdev->blk), &ioreq->acct,
ioreq->v.size, BLOCK_ACCT_READ);
ioreq->aio_inflight++;
blk_aio_preadv(blkdev->blk, ioreq->start, &ioreq->v, 0,
qemu_aio_complete, ioreq);
break;
case BLKIF_OP_WRITE:
case BLKIF_OP_FLUSH_DISKCACHE:
if (!ioreq->req.nr_segments) {
break;
}
qemu_iovec_add(&ioreq->v, ioreq->buf, ioreq->size);
block_acct_start(blk_get_stats(blkdev->blk), &ioreq->acct,
ioreq->v.size,
ioreq->req.operation == BLKIF_OP_WRITE ?
BLOCK_ACCT_WRITE : BLOCK_ACCT_FLUSH);
ioreq->aio_inflight++;
blk_aio_pwritev(blkdev->blk, ioreq->start, &ioreq->v, 0,
qemu_aio_complete, ioreq);
break;
case BLKIF_OP_DISCARD:
{
struct blkif_request_discard *req = (void *)&ioreq->req;
if (!blk_split_discard(ioreq, req->sector_number, req->nr_sectors)) {
goto err;
}
break;
}
default:
/* unknown operation (shouldn't happen -- parse catches this) */
goto err;
}
qemu_aio_complete(ioreq, 0);
return 0;
err:
ioreq_finish(ioreq);
ioreq->status = BLKIF_RSP_ERROR;
return -1;
}
static int blk_send_response_one(struct ioreq *ioreq)
{
struct XenBlkDev *blkdev = ioreq->blkdev;
int send_notify = 0;
int have_requests = 0;
blkif_response_t *resp;
/* Place on the response ring for the relevant domain. */
switch (blkdev->protocol) {
case BLKIF_PROTOCOL_NATIVE:
resp = (blkif_response_t *) RING_GET_RESPONSE(&blkdev->rings.native,
blkdev->rings.native.rsp_prod_pvt);
break;
case BLKIF_PROTOCOL_X86_32:
resp = (blkif_response_t *) RING_GET_RESPONSE(&blkdev->rings.x86_32_part,
blkdev->rings.x86_32_part.rsp_prod_pvt);
break;
case BLKIF_PROTOCOL_X86_64:
resp = (blkif_response_t *) RING_GET_RESPONSE(&blkdev->rings.x86_64_part,
blkdev->rings.x86_64_part.rsp_prod_pvt);
break;
default:
return 0;
}
resp->id = ioreq->req.id;
resp->operation = ioreq->req.operation;
resp->status = ioreq->status;
blkdev->rings.common.rsp_prod_pvt++;
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify);
if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
/*
* Tail check for pending requests. Allows frontend to avoid
* notifications if requests are already in flight (lower
* overheads and promotes batching).
*/
RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests);
} else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) {
have_requests = 1;
}
if (have_requests) {
blkdev->more_work++;
}
return send_notify;
}
/* walk finished list, send outstanding responses, free requests */
static void blk_send_response_all(struct XenBlkDev *blkdev)
{
struct ioreq *ioreq;
int send_notify = 0;
while (!QLIST_EMPTY(&blkdev->finished)) {
ioreq = QLIST_FIRST(&blkdev->finished);
send_notify += blk_send_response_one(ioreq);
ioreq_release(ioreq, true);
}
if (send_notify) {
xen_pv_send_notify(&blkdev->xendev);
}
}
static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc)
{
switch (blkdev->protocol) {
case BLKIF_PROTOCOL_NATIVE:
memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc),
sizeof(ioreq->req));
break;
case BLKIF_PROTOCOL_X86_32:
blkif_get_x86_32_req(&ioreq->req,
RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc));
break;
case BLKIF_PROTOCOL_X86_64:
blkif_get_x86_64_req(&ioreq->req,
RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc));
break;
}
/* Prevent the compiler from accessing the on-ring fields instead. */
barrier();
return 0;
}
static void blk_handle_requests(struct XenBlkDev *blkdev)
{
RING_IDX rc, rp;
struct ioreq *ioreq;
blkdev->more_work = 0;
rc = blkdev->rings.common.req_cons;
rp = blkdev->rings.common.sring->req_prod;
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
blk_send_response_all(blkdev);
while (rc != rp) {
/* pull request from ring */
if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
break;
}
ioreq = ioreq_start(blkdev);
if (ioreq == NULL) {
blkdev->more_work++;
break;
}
blk_get_request(blkdev, ioreq, rc);
blkdev->rings.common.req_cons = ++rc;
/* parse them */
if (ioreq_parse(ioreq) != 0) {
switch (ioreq->req.operation) {
case BLKIF_OP_READ:
block_acct_invalid(blk_get_stats(blkdev->blk),
BLOCK_ACCT_READ);
break;
case BLKIF_OP_WRITE:
block_acct_invalid(blk_get_stats(blkdev->blk),
BLOCK_ACCT_WRITE);
break;
case BLKIF_OP_FLUSH_DISKCACHE:
block_acct_invalid(blk_get_stats(blkdev->blk),
BLOCK_ACCT_FLUSH);
default:
break;
};
if (blk_send_response_one(ioreq)) {
xen_pv_send_notify(&blkdev->xendev);
}
ioreq_release(ioreq, false);
continue;
}
ioreq_runio_qemu_aio(ioreq);
}
if (blkdev->more_work && blkdev->requests_inflight < blkdev->max_requests) {
qemu_bh_schedule(blkdev->bh);
}
}
/* ------------------------------------------------------------- */
static void blk_bh(void *opaque)
{
struct XenBlkDev *blkdev = opaque;
aio_context_acquire(blkdev->ctx);
blk_handle_requests(blkdev);
aio_context_release(blkdev->ctx);
}
static void blk_alloc(struct XenDevice *xendev)
{
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
Error *err = NULL;
trace_xen_disk_alloc(xendev->name);
QLIST_INIT(&blkdev->inflight);
QLIST_INIT(&blkdev->finished);
QLIST_INIT(&blkdev->freelist);
blkdev->iothread = iothread_create(xendev->name, &err);
assert(!err);
blkdev->ctx = iothread_get_aio_context(blkdev->iothread);
blkdev->bh = aio_bh_new(blkdev->ctx, blk_bh, blkdev);
}
static void blk_parse_discard(struct XenBlkDev *blkdev)
{
struct XenDevice *xendev = &blkdev->xendev;
int enable;
blkdev->feature_discard = true;
if (xenstore_read_be_int(xendev, "discard-enable", &enable) == 0) {
blkdev->feature_discard = !!enable;
}
if (blkdev->feature_discard) {
xenstore_write_be_int(xendev, "feature-discard", 1);
}
}
static int blk_init(struct XenDevice *xendev)
{
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
int info = 0;
char *directiosafe = NULL;
trace_xen_disk_init(xendev->name);
/* read xenstore entries */
if (blkdev->params == NULL) {
char *h = NULL;
blkdev->params = xenstore_read_be_str(xendev, "params");
if (blkdev->params != NULL) {
h = strchr(blkdev->params, ':');
}
if (h != NULL) {
blkdev->fileproto = blkdev->params;
blkdev->filename = h+1;
*h = 0;
} else {
blkdev->fileproto = "<unset>";
blkdev->filename = blkdev->params;
}
}
if (!strcmp("aio", blkdev->fileproto)) {
blkdev->fileproto = "raw";
}
if (!strcmp("vhd", blkdev->fileproto)) {
blkdev->fileproto = "vpc";
}
if (blkdev->mode == NULL) {
blkdev->mode = xenstore_read_be_str(xendev, "mode");
}
if (blkdev->type == NULL) {
blkdev->type = xenstore_read_be_str(xendev, "type");
}
if (blkdev->dev == NULL) {
blkdev->dev = xenstore_read_be_str(xendev, "dev");
}
if (blkdev->devtype == NULL) {
blkdev->devtype = xenstore_read_be_str(xendev, "device-type");
}
directiosafe = xenstore_read_be_str(xendev, "direct-io-safe");
blkdev->directiosafe = (directiosafe && atoi(directiosafe));
/* do we have all we need? */
if (blkdev->params == NULL ||
blkdev->mode == NULL ||
blkdev->type == NULL ||
blkdev->dev == NULL) {
goto out_error;
}
/* read-only ? */
if (strcmp(blkdev->mode, "w")) {
info |= VDISK_READONLY;
}
/* cdrom ? */
if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) {
info |= VDISK_CDROM;
}
blkdev->file_blk = BLOCK_SIZE;
/* fill info
* blk_connect supplies sector-size and sectors
*/
xenstore_write_be_int(xendev, "feature-flush-cache", 1);
xenstore_write_be_int(xendev, "info", info);
xenstore_write_be_int(xendev, "max-ring-page-order",
MAX_RING_PAGE_ORDER);
blk_parse_discard(blkdev);
g_free(directiosafe);
return 0;
out_error:
g_free(blkdev->params);
blkdev->params = NULL;
g_free(blkdev->mode);
blkdev->mode = NULL;
g_free(blkdev->type);
blkdev->type = NULL;
g_free(blkdev->dev);
blkdev->dev = NULL;
g_free(blkdev->devtype);
blkdev->devtype = NULL;
g_free(directiosafe);
blkdev->directiosafe = false;
return -1;
}
static int blk_connect(struct XenDevice *xendev)
{
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
int index, qflags;
bool readonly = true;
bool writethrough = true;
int order, ring_ref;
unsigned int ring_size, max_grants;
unsigned int i;
trace_xen_disk_connect(xendev->name);
/* read-only ? */
if (blkdev->directiosafe) {
qflags = BDRV_O_NOCACHE | BDRV_O_NATIVE_AIO;
} else {
qflags = 0;
writethrough = false;
}
if (strcmp(blkdev->mode, "w") == 0) {
qflags |= BDRV_O_RDWR;
readonly = false;
}
if (blkdev->feature_discard) {
qflags |= BDRV_O_UNMAP;
}
/* init qemu block driver */
index = (xendev->dev - 202 * 256) / 16;
blkdev->dinfo = drive_get(IF_XEN, 0, index);
if (!blkdev->dinfo) {
Error *local_err = NULL;
QDict *options = NULL;
if (strcmp(blkdev->fileproto, "<unset>")) {
options = qdict_new();
qdict_put_str(options, "driver", blkdev->fileproto);
}
/* setup via xenbus -> create new block driver instance */
xen_pv_printf(xendev, 2, "create new bdrv (xenbus setup)\n");
blkdev->blk = blk_new_open(blkdev->filename, NULL, options,
qflags, &local_err);
if (!blkdev->blk) {
xen_pv_printf(xendev, 0, "error: %s\n",
error_get_pretty(local_err));
error_free(local_err);
return -1;
}
blk_set_enable_write_cache(blkdev->blk, !writethrough);
} else {
/* setup via qemu cmdline -> already setup for us */
xen_pv_printf(xendev, 2,
"get configured bdrv (cmdline setup)\n");
blkdev->blk = blk_by_legacy_dinfo(blkdev->dinfo);
if (blk_is_read_only(blkdev->blk) && !readonly) {
xen_pv_printf(xendev, 0, "Unexpected read-only drive");
blkdev->blk = NULL;
return -1;
}
/* blkdev->blk is not create by us, we get a reference
* so we can blk_unref() unconditionally */
blk_ref(blkdev->blk);
}
blk_attach_dev_legacy(blkdev->blk, blkdev);
blkdev->file_size = blk_getlength(blkdev->blk);
if (blkdev->file_size < 0) {
BlockDriverState *bs = blk_bs(blkdev->blk);
const char *drv_name = bs ? bdrv_get_format_name(bs) : NULL;
xen_pv_printf(xendev, 1, "blk_getlength: %d (%s) | drv %s\n",
(int)blkdev->file_size, strerror(-blkdev->file_size),
drv_name ?: "-");
blkdev->file_size = 0;
}
xen_pv_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\","
" size %" PRId64 " (%" PRId64 " MB)\n",
blkdev->type, blkdev->fileproto, blkdev->filename,
blkdev->file_size, blkdev->file_size >> 20);
/* Fill in number of sector size and number of sectors */
xenstore_write_be_int(xendev, "sector-size", blkdev->file_blk);
xenstore_write_be_int64(xendev, "sectors",
blkdev->file_size / blkdev->file_blk);
if (xenstore_read_fe_int(xendev, "ring-page-order",
&order) == -1) {
blkdev->nr_ring_ref = 1;
if (xenstore_read_fe_int(xendev, "ring-ref",
&ring_ref) == -1) {
return -1;
}
blkdev->ring_ref[0] = ring_ref;
} else if (order >= 0 && order <= MAX_RING_PAGE_ORDER) {
blkdev->nr_ring_ref = 1 << order;
for (i = 0; i < blkdev->nr_ring_ref; i++) {
char *key;
key = g_strdup_printf("ring-ref%u", i);
if (!key) {
return -1;
}
if (xenstore_read_fe_int(xendev, key,
&ring_ref) == -1) {
g_free(key);
return -1;
}
blkdev->ring_ref[i] = ring_ref;
g_free(key);
}
} else {
xen_pv_printf(xendev, 0, "invalid ring-page-order: %d\n",
order);
return -1;
}
if (xenstore_read_fe_int(xendev, "event-channel",
&xendev->remote_port) == -1) {
return -1;
}
if (!xendev->protocol) {
blkdev->protocol = BLKIF_PROTOCOL_NATIVE;
} else if (strcmp(xendev->protocol, XEN_IO_PROTO_ABI_NATIVE) == 0) {
blkdev->protocol = BLKIF_PROTOCOL_NATIVE;
} else if (strcmp(xendev->protocol, XEN_IO_PROTO_ABI_X86_32) == 0) {
blkdev->protocol = BLKIF_PROTOCOL_X86_32;
} else if (strcmp(xendev->protocol, XEN_IO_PROTO_ABI_X86_64) == 0) {
blkdev->protocol = BLKIF_PROTOCOL_X86_64;
} else {
blkdev->protocol = BLKIF_PROTOCOL_NATIVE;
}
ring_size = XC_PAGE_SIZE * blkdev->nr_ring_ref;
switch (blkdev->protocol) {
case BLKIF_PROTOCOL_NATIVE:
{
blkdev->max_requests = __CONST_RING_SIZE(blkif, ring_size);
break;
}
case BLKIF_PROTOCOL_X86_32:
{
blkdev->max_requests = __CONST_RING_SIZE(blkif_x86_32, ring_size);
break;
}
case BLKIF_PROTOCOL_X86_64:
{
blkdev->max_requests = __CONST_RING_SIZE(blkif_x86_64, ring_size);
break;
}
default:
return -1;
}
/* Add on the number needed for the ring pages */
max_grants = blkdev->nr_ring_ref;
xen_be_set_max_grant_refs(xendev, max_grants);
blkdev->sring = xen_be_map_grant_refs(xendev, blkdev->ring_ref,
blkdev->nr_ring_ref,
PROT_READ | PROT_WRITE);
if (!blkdev->sring) {
return -1;
}
switch (blkdev->protocol) {
case BLKIF_PROTOCOL_NATIVE:
{
blkif_sring_t *sring_native = blkdev->sring;
BACK_RING_INIT(&blkdev->rings.native, sring_native, ring_size);
break;
}
case BLKIF_PROTOCOL_X86_32:
{
blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring;
BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, ring_size);
break;
}
case BLKIF_PROTOCOL_X86_64:
{
blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring;
BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, ring_size);
break;
}
}
blk_set_aio_context(blkdev->blk, blkdev->ctx);
xen_be_bind_evtchn(xendev);
xen_pv_printf(xendev, 1, "ok: proto %s, nr-ring-ref %u, "
"remote port %d, local port %d\n",
xendev->protocol, blkdev->nr_ring_ref,
xendev->remote_port, xendev->local_port);
return 0;
}
static void blk_disconnect(struct XenDevice *xendev)
{
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
trace_xen_disk_disconnect(xendev->name);
aio_context_acquire(blkdev->ctx);
if (blkdev->blk) {
blk_set_aio_context(blkdev->blk, qemu_get_aio_context());
blk_detach_dev(blkdev->blk, blkdev);
blk_unref(blkdev->blk);
blkdev->blk = NULL;
}
xen_pv_unbind_evtchn(xendev);
aio_context_release(blkdev->ctx);
if (blkdev->sring) {
xen_be_unmap_grant_refs(xendev, blkdev->sring,
blkdev->nr_ring_ref);
blkdev->sring = NULL;
}
}
static int blk_free(struct XenDevice *xendev)
{
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
struct ioreq *ioreq;
trace_xen_disk_free(xendev->name);
blk_disconnect(xendev);
while (!QLIST_EMPTY(&blkdev->freelist)) {
ioreq = QLIST_FIRST(&blkdev->freelist);
QLIST_REMOVE(ioreq, list);
qemu_iovec_destroy(&ioreq->v);
g_free(ioreq);
}
g_free(blkdev->params);
g_free(blkdev->mode);
g_free(blkdev->type);
g_free(blkdev->dev);
g_free(blkdev->devtype);
qemu_bh_delete(blkdev->bh);
iothread_destroy(blkdev->iothread);
return 0;
}
static void blk_event(struct XenDevice *xendev)
{
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
qemu_bh_schedule(blkdev->bh);
}
struct XenDevOps xen_blkdev_ops = {
.flags = DEVOPS_FLAG_NEED_GNTDEV,
.size = sizeof(struct XenBlkDev),
.alloc = blk_alloc,
.init = blk_init,
.initialise = blk_connect,
.disconnect = blk_disconnect,
.event = blk_event,
.free = blk_free,
};
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