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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> |
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#include <stdlib.h> |
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#include <stdarg.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include <signal.h> |
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#include <inttypes.h> |
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#include <time.h> |
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#include <fcntl.h> |
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#include <errno.h> |
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#include <sys/ioctl.h> |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <sys/mman.h> |
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#include <sys/uio.h> |
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|
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#include <xs.h> |
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#include <xenctrl.h> |
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#include <xen/io/xenbus.h> |
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|
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#include "hw.h" |
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#include "block_int.h" |
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#include "qemu-char.h" |
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#include "xen_blkif.h" |
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#include "xen_backend.h" |
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#include "blockdev.h" |
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/* ------------------------------------------------------------- */
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static int batch_maps = 0; |
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static int max_requests = 32; |
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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) |
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|
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struct ioreq {
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blkif_request_t req; |
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int16_t status; |
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/* parsed request */
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off_t start; |
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QEMUIOVector v; |
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int presync;
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int postsync;
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uint8_t mapped; |
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|
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/* grant mapping */
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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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int prot;
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void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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void *pages;
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|
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/* aio status */
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int aio_inflight;
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int aio_errors;
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|
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struct XenBlkDev *blkdev;
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QLIST_ENTRY(ioreq) list; |
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BlockAcctCookie acct; |
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}; |
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|
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struct XenBlkDev {
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struct XenDevice xendev; /* must be first */ |
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char *params;
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char *mode;
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char *type;
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char *dev;
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char *devtype;
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const char *fileproto; |
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const char *filename; |
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int ring_ref;
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void *sring;
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int64_t file_blk; |
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int64_t file_size; |
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int protocol;
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blkif_back_rings_t rings; |
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int more_work;
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int cnt_map;
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/* 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;
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int requests_finished;
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|
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/* qemu block driver */
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DriveInfo *dinfo; |
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BlockDriverState *bs; |
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QEMUBH *bh; |
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}; |
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|
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/* ------------------------------------------------------------- */
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|
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static struct ioreq *ioreq_start(struct XenBlkDev *blkdev) |
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{ |
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struct ioreq *ioreq = NULL; |
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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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} |
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/* allocate new struct */
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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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} else {
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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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qemu_iovec_reset(&ioreq->v); |
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} |
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QLIST_INSERT_HEAD(&blkdev->inflight, ioreq, list); |
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blkdev->requests_inflight++; |
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out:
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return ioreq;
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} |
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static void ioreq_finish(struct ioreq *ioreq) |
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{ |
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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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} |
156 |
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static void ioreq_release(struct ioreq *ioreq, bool finish) |
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{ |
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struct XenBlkDev *blkdev = ioreq->blkdev;
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|
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QLIST_REMOVE(ioreq, list); |
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memset(ioreq, 0, sizeof(*ioreq)); |
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ioreq->blkdev = blkdev; |
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QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list); |
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if (finish) {
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blkdev->requests_finished--; |
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} else {
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blkdev->requests_inflight--; |
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} |
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} |
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/*
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* translate request into iovec + start offset
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* do sanity checks along the way
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*/
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static int ioreq_parse(struct ioreq *ioreq) |
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{ |
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struct XenBlkDev *blkdev = ioreq->blkdev;
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uintptr_t mem; |
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size_t len; |
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int i;
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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); |
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switch (ioreq->req.operation) {
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case BLKIF_OP_READ:
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ioreq->prot = PROT_WRITE; /* to memory */
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break;
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case BLKIF_OP_WRITE_BARRIER:
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if (!ioreq->req.nr_segments) {
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ioreq->presync = 1;
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return 0; |
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} |
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ioreq->presync = ioreq->postsync = 1;
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/* fall through */
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case BLKIF_OP_WRITE:
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ioreq->prot = PROT_READ; /* from memory */
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break;
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default:
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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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goto err;
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}; |
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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;
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} |
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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;
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} |
218 |
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;
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} |
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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"); |
224 |
goto err;
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} |
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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;
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qemu_iovec_add(&ioreq->v, (void*)mem, len);
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} |
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if (ioreq->start + ioreq->v.size > blkdev->file_size) {
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xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n"); |
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goto err;
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} |
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return 0; |
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|
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err:
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ioreq->status = BLKIF_RSP_ERROR; |
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return -1; |
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} |
244 |
|
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static void ioreq_unmap(struct ioreq *ioreq) |
246 |
{ |
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XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
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int i;
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if (ioreq->v.niov == 0 || ioreq->mapped == 0) { |
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return;
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} |
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if (batch_maps) {
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if (!ioreq->pages) {
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return;
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} |
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if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->v.niov) != 0) { |
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xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
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strerror(errno)); |
260 |
} |
261 |
ioreq->blkdev->cnt_map -= ioreq->v.niov; |
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ioreq->pages = NULL;
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} else {
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for (i = 0; i < ioreq->v.niov; i++) { |
265 |
if (!ioreq->page[i]) {
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continue;
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} |
268 |
if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0) { |
269 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
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strerror(errno)); |
271 |
} |
272 |
ioreq->blkdev->cnt_map--; |
273 |
ioreq->page[i] = NULL;
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} |
275 |
} |
276 |
ioreq->mapped = 0;
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} |
278 |
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static int ioreq_map(struct ioreq *ioreq) |
280 |
{ |
281 |
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
282 |
int i;
|
283 |
|
284 |
if (ioreq->v.niov == 0 || ioreq->mapped == 1) { |
285 |
return 0; |
286 |
} |
287 |
if (batch_maps) {
|
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ioreq->pages = xc_gnttab_map_grant_refs |
289 |
(gnt, ioreq->v.niov, ioreq->domids, ioreq->refs, ioreq->prot); |
290 |
if (ioreq->pages == NULL) { |
291 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
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"can't map %d grant refs (%s, %d maps)\n",
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293 |
ioreq->v.niov, strerror(errno), ioreq->blkdev->cnt_map); |
294 |
return -1; |
295 |
} |
296 |
for (i = 0; i < ioreq->v.niov; i++) { |
297 |
ioreq->v.iov[i].iov_base = ioreq->pages + i * XC_PAGE_SIZE + |
298 |
(uintptr_t)ioreq->v.iov[i].iov_base; |
299 |
} |
300 |
ioreq->blkdev->cnt_map += ioreq->v.niov; |
301 |
} else {
|
302 |
for (i = 0; i < ioreq->v.niov; i++) { |
303 |
ioreq->page[i] = xc_gnttab_map_grant_ref |
304 |
(gnt, ioreq->domids[i], ioreq->refs[i], ioreq->prot); |
305 |
if (ioreq->page[i] == NULL) { |
306 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
|
307 |
"can't map grant ref %d (%s, %d maps)\n",
|
308 |
ioreq->refs[i], strerror(errno), ioreq->blkdev->cnt_map); |
309 |
ioreq_unmap(ioreq); |
310 |
return -1; |
311 |
} |
312 |
ioreq->v.iov[i].iov_base = ioreq->page[i] + (uintptr_t)ioreq->v.iov[i].iov_base; |
313 |
ioreq->blkdev->cnt_map++; |
314 |
} |
315 |
} |
316 |
ioreq->mapped = 1;
|
317 |
return 0; |
318 |
} |
319 |
|
320 |
static int ioreq_runio_qemu_aio(struct ioreq *ioreq); |
321 |
|
322 |
static void qemu_aio_complete(void *opaque, int ret) |
323 |
{ |
324 |
struct ioreq *ioreq = opaque;
|
325 |
|
326 |
if (ret != 0) { |
327 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n", |
328 |
ioreq->req.operation == BLKIF_OP_READ ? "read" : "write"); |
329 |
ioreq->aio_errors++; |
330 |
} |
331 |
|
332 |
ioreq->aio_inflight--; |
333 |
if (ioreq->presync) {
|
334 |
ioreq->presync = 0;
|
335 |
ioreq_runio_qemu_aio(ioreq); |
336 |
return;
|
337 |
} |
338 |
if (ioreq->aio_inflight > 0) { |
339 |
return;
|
340 |
} |
341 |
if (ioreq->postsync) {
|
342 |
ioreq->postsync = 0;
|
343 |
ioreq->aio_inflight++; |
344 |
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq); |
345 |
return;
|
346 |
} |
347 |
|
348 |
ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY; |
349 |
ioreq_unmap(ioreq); |
350 |
ioreq_finish(ioreq); |
351 |
bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct); |
352 |
qemu_bh_schedule(ioreq->blkdev->bh); |
353 |
} |
354 |
|
355 |
static int ioreq_runio_qemu_aio(struct ioreq *ioreq) |
356 |
{ |
357 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
358 |
|
359 |
if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) { |
360 |
goto err_no_map;
|
361 |
} |
362 |
|
363 |
ioreq->aio_inflight++; |
364 |
if (ioreq->presync) {
|
365 |
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq); |
366 |
return 0; |
367 |
} |
368 |
|
369 |
switch (ioreq->req.operation) {
|
370 |
case BLKIF_OP_READ:
|
371 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_READ); |
372 |
ioreq->aio_inflight++; |
373 |
bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE, |
374 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
375 |
qemu_aio_complete, ioreq); |
376 |
break;
|
377 |
case BLKIF_OP_WRITE:
|
378 |
case BLKIF_OP_WRITE_BARRIER:
|
379 |
if (!ioreq->req.nr_segments) {
|
380 |
break;
|
381 |
} |
382 |
|
383 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_WRITE); |
384 |
ioreq->aio_inflight++; |
385 |
bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE, |
386 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
387 |
qemu_aio_complete, ioreq); |
388 |
break;
|
389 |
default:
|
390 |
/* unknown operation (shouldn't happen -- parse catches this) */
|
391 |
goto err;
|
392 |
} |
393 |
|
394 |
qemu_aio_complete(ioreq, 0);
|
395 |
|
396 |
return 0; |
397 |
|
398 |
err:
|
399 |
ioreq_unmap(ioreq); |
400 |
err_no_map:
|
401 |
ioreq_finish(ioreq); |
402 |
ioreq->status = BLKIF_RSP_ERROR; |
403 |
return -1; |
404 |
} |
405 |
|
406 |
static int blk_send_response_one(struct ioreq *ioreq) |
407 |
{ |
408 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
409 |
int send_notify = 0; |
410 |
int have_requests = 0; |
411 |
blkif_response_t resp; |
412 |
void *dst;
|
413 |
|
414 |
resp.id = ioreq->req.id; |
415 |
resp.operation = ioreq->req.operation; |
416 |
resp.status = ioreq->status; |
417 |
|
418 |
/* Place on the response ring for the relevant domain. */
|
419 |
switch (blkdev->protocol) {
|
420 |
case BLKIF_PROTOCOL_NATIVE:
|
421 |
dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt); |
422 |
break;
|
423 |
case BLKIF_PROTOCOL_X86_32:
|
424 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part, |
425 |
blkdev->rings.x86_32_part.rsp_prod_pvt); |
426 |
break;
|
427 |
case BLKIF_PROTOCOL_X86_64:
|
428 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part, |
429 |
blkdev->rings.x86_64_part.rsp_prod_pvt); |
430 |
break;
|
431 |
default:
|
432 |
dst = NULL;
|
433 |
} |
434 |
memcpy(dst, &resp, sizeof(resp));
|
435 |
blkdev->rings.common.rsp_prod_pvt++; |
436 |
|
437 |
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify); |
438 |
if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
|
439 |
/*
|
440 |
* Tail check for pending requests. Allows frontend to avoid
|
441 |
* notifications if requests are already in flight (lower
|
442 |
* overheads and promotes batching).
|
443 |
*/
|
444 |
RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests); |
445 |
} else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) { |
446 |
have_requests = 1;
|
447 |
} |
448 |
|
449 |
if (have_requests) {
|
450 |
blkdev->more_work++; |
451 |
} |
452 |
return send_notify;
|
453 |
} |
454 |
|
455 |
/* walk finished list, send outstanding responses, free requests */
|
456 |
static void blk_send_response_all(struct XenBlkDev *blkdev) |
457 |
{ |
458 |
struct ioreq *ioreq;
|
459 |
int send_notify = 0; |
460 |
|
461 |
while (!QLIST_EMPTY(&blkdev->finished)) {
|
462 |
ioreq = QLIST_FIRST(&blkdev->finished); |
463 |
send_notify += blk_send_response_one(ioreq); |
464 |
ioreq_release(ioreq, true);
|
465 |
} |
466 |
if (send_notify) {
|
467 |
xen_be_send_notify(&blkdev->xendev); |
468 |
} |
469 |
} |
470 |
|
471 |
static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc) |
472 |
{ |
473 |
switch (blkdev->protocol) {
|
474 |
case BLKIF_PROTOCOL_NATIVE:
|
475 |
memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc), |
476 |
sizeof(ioreq->req));
|
477 |
break;
|
478 |
case BLKIF_PROTOCOL_X86_32:
|
479 |
blkif_get_x86_32_req(&ioreq->req, |
480 |
RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc)); |
481 |
break;
|
482 |
case BLKIF_PROTOCOL_X86_64:
|
483 |
blkif_get_x86_64_req(&ioreq->req, |
484 |
RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc)); |
485 |
break;
|
486 |
} |
487 |
return 0; |
488 |
} |
489 |
|
490 |
static void blk_handle_requests(struct XenBlkDev *blkdev) |
491 |
{ |
492 |
RING_IDX rc, rp; |
493 |
struct ioreq *ioreq;
|
494 |
|
495 |
blkdev->more_work = 0;
|
496 |
|
497 |
rc = blkdev->rings.common.req_cons; |
498 |
rp = blkdev->rings.common.sring->req_prod; |
499 |
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
|
500 |
|
501 |
blk_send_response_all(blkdev); |
502 |
while (rc != rp) {
|
503 |
/* pull request from ring */
|
504 |
if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
|
505 |
break;
|
506 |
} |
507 |
ioreq = ioreq_start(blkdev); |
508 |
if (ioreq == NULL) { |
509 |
blkdev->more_work++; |
510 |
break;
|
511 |
} |
512 |
blk_get_request(blkdev, ioreq, rc); |
513 |
blkdev->rings.common.req_cons = ++rc; |
514 |
|
515 |
/* parse them */
|
516 |
if (ioreq_parse(ioreq) != 0) { |
517 |
if (blk_send_response_one(ioreq)) {
|
518 |
xen_be_send_notify(&blkdev->xendev); |
519 |
} |
520 |
ioreq_release(ioreq, false);
|
521 |
continue;
|
522 |
} |
523 |
|
524 |
ioreq_runio_qemu_aio(ioreq); |
525 |
} |
526 |
|
527 |
if (blkdev->more_work && blkdev->requests_inflight < max_requests) {
|
528 |
qemu_bh_schedule(blkdev->bh); |
529 |
} |
530 |
} |
531 |
|
532 |
/* ------------------------------------------------------------- */
|
533 |
|
534 |
static void blk_bh(void *opaque) |
535 |
{ |
536 |
struct XenBlkDev *blkdev = opaque;
|
537 |
blk_handle_requests(blkdev); |
538 |
} |
539 |
|
540 |
/*
|
541 |
* We need to account for the grant allocations requiring contiguous
|
542 |
* chunks; the worst case number would be
|
543 |
* max_req * max_seg + (max_req - 1) * (max_seg - 1) + 1,
|
544 |
* but in order to keep things simple just use
|
545 |
* 2 * max_req * max_seg.
|
546 |
*/
|
547 |
#define MAX_GRANTS(max_req, max_seg) (2 * (max_req) * (max_seg)) |
548 |
|
549 |
static void blk_alloc(struct XenDevice *xendev) |
550 |
{ |
551 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
552 |
|
553 |
QLIST_INIT(&blkdev->inflight); |
554 |
QLIST_INIT(&blkdev->finished); |
555 |
QLIST_INIT(&blkdev->freelist); |
556 |
blkdev->bh = qemu_bh_new(blk_bh, blkdev); |
557 |
if (xen_mode != XEN_EMULATE) {
|
558 |
batch_maps = 1;
|
559 |
} |
560 |
if (xc_gnttab_set_max_grants(xendev->gnttabdev,
|
561 |
MAX_GRANTS(max_requests, BLKIF_MAX_SEGMENTS_PER_REQUEST)) < 0) {
|
562 |
xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n", |
563 |
strerror(errno)); |
564 |
} |
565 |
} |
566 |
|
567 |
static int blk_init(struct XenDevice *xendev) |
568 |
{ |
569 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
570 |
int index, qflags, info = 0; |
571 |
|
572 |
/* read xenstore entries */
|
573 |
if (blkdev->params == NULL) { |
574 |
char *h = NULL; |
575 |
blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params");
|
576 |
if (blkdev->params != NULL) { |
577 |
h = strchr(blkdev->params, ':');
|
578 |
} |
579 |
if (h != NULL) { |
580 |
blkdev->fileproto = blkdev->params; |
581 |
blkdev->filename = h+1;
|
582 |
*h = 0;
|
583 |
} else {
|
584 |
blkdev->fileproto = "<unset>";
|
585 |
blkdev->filename = blkdev->params; |
586 |
} |
587 |
} |
588 |
if (!strcmp("aio", blkdev->fileproto)) { |
589 |
blkdev->fileproto = "raw";
|
590 |
} |
591 |
if (blkdev->mode == NULL) { |
592 |
blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
|
593 |
} |
594 |
if (blkdev->type == NULL) { |
595 |
blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type");
|
596 |
} |
597 |
if (blkdev->dev == NULL) { |
598 |
blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev");
|
599 |
} |
600 |
if (blkdev->devtype == NULL) { |
601 |
blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type");
|
602 |
} |
603 |
|
604 |
/* do we have all we need? */
|
605 |
if (blkdev->params == NULL || |
606 |
blkdev->mode == NULL ||
|
607 |
blkdev->type == NULL ||
|
608 |
blkdev->dev == NULL) {
|
609 |
goto out_error;
|
610 |
} |
611 |
|
612 |
/* read-only ? */
|
613 |
qflags = BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NATIVE_AIO; |
614 |
if (strcmp(blkdev->mode, "w") == 0) { |
615 |
qflags |= BDRV_O_RDWR; |
616 |
} else {
|
617 |
info |= VDISK_READONLY; |
618 |
} |
619 |
|
620 |
/* cdrom ? */
|
621 |
if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) { |
622 |
info |= VDISK_CDROM; |
623 |
} |
624 |
|
625 |
/* init qemu block driver */
|
626 |
index = (blkdev->xendev.dev - 202 * 256) / 16; |
627 |
blkdev->dinfo = drive_get(IF_XEN, 0, index);
|
628 |
if (!blkdev->dinfo) {
|
629 |
/* setup via xenbus -> create new block driver instance */
|
630 |
xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n"); |
631 |
blkdev->bs = bdrv_new(blkdev->dev); |
632 |
if (blkdev->bs) {
|
633 |
if (bdrv_open(blkdev->bs, blkdev->filename, qflags,
|
634 |
bdrv_find_whitelisted_format(blkdev->fileproto)) != 0) {
|
635 |
bdrv_delete(blkdev->bs); |
636 |
blkdev->bs = NULL;
|
637 |
} |
638 |
} |
639 |
if (!blkdev->bs) {
|
640 |
goto out_error;
|
641 |
} |
642 |
} else {
|
643 |
/* setup via qemu cmdline -> already setup for us */
|
644 |
xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n"); |
645 |
blkdev->bs = blkdev->dinfo->bdrv; |
646 |
} |
647 |
bdrv_attach_dev_nofail(blkdev->bs, blkdev); |
648 |
blkdev->file_blk = BLOCK_SIZE; |
649 |
blkdev->file_size = bdrv_getlength(blkdev->bs); |
650 |
if (blkdev->file_size < 0) { |
651 |
xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n", |
652 |
(int)blkdev->file_size, strerror(-blkdev->file_size),
|
653 |
blkdev->bs->drv ? blkdev->bs->drv->format_name : "-");
|
654 |
blkdev->file_size = 0;
|
655 |
} |
656 |
|
657 |
xen_be_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\"," |
658 |
" size %" PRId64 " (%" PRId64 " MB)\n", |
659 |
blkdev->type, blkdev->fileproto, blkdev->filename, |
660 |
blkdev->file_size, blkdev->file_size >> 20);
|
661 |
|
662 |
/* fill info */
|
663 |
xenstore_write_be_int(&blkdev->xendev, "feature-barrier", 1); |
664 |
xenstore_write_be_int(&blkdev->xendev, "info", info);
|
665 |
xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk);
|
666 |
xenstore_write_be_int(&blkdev->xendev, "sectors",
|
667 |
blkdev->file_size / blkdev->file_blk); |
668 |
return 0; |
669 |
|
670 |
out_error:
|
671 |
g_free(blkdev->params); |
672 |
blkdev->params = NULL;
|
673 |
g_free(blkdev->mode); |
674 |
blkdev->mode = NULL;
|
675 |
g_free(blkdev->type); |
676 |
blkdev->type = NULL;
|
677 |
g_free(blkdev->dev); |
678 |
blkdev->dev = NULL;
|
679 |
g_free(blkdev->devtype); |
680 |
blkdev->devtype = NULL;
|
681 |
return -1; |
682 |
} |
683 |
|
684 |
static int blk_connect(struct XenDevice *xendev) |
685 |
{ |
686 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
687 |
|
688 |
if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) { |
689 |
return -1; |
690 |
} |
691 |
if (xenstore_read_fe_int(&blkdev->xendev, "event-channel", |
692 |
&blkdev->xendev.remote_port) == -1) {
|
693 |
return -1; |
694 |
} |
695 |
|
696 |
blkdev->protocol = BLKIF_PROTOCOL_NATIVE; |
697 |
if (blkdev->xendev.protocol) {
|
698 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { |
699 |
blkdev->protocol = BLKIF_PROTOCOL_X86_32; |
700 |
} |
701 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { |
702 |
blkdev->protocol = BLKIF_PROTOCOL_X86_64; |
703 |
} |
704 |
} |
705 |
|
706 |
blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev, |
707 |
blkdev->xendev.dom, |
708 |
blkdev->ring_ref, |
709 |
PROT_READ | PROT_WRITE); |
710 |
if (!blkdev->sring) {
|
711 |
return -1; |
712 |
} |
713 |
blkdev->cnt_map++; |
714 |
|
715 |
switch (blkdev->protocol) {
|
716 |
case BLKIF_PROTOCOL_NATIVE:
|
717 |
{ |
718 |
blkif_sring_t *sring_native = blkdev->sring; |
719 |
BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_SIZE); |
720 |
break;
|
721 |
} |
722 |
case BLKIF_PROTOCOL_X86_32:
|
723 |
{ |
724 |
blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring; |
725 |
|
726 |
BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, XC_PAGE_SIZE); |
727 |
break;
|
728 |
} |
729 |
case BLKIF_PROTOCOL_X86_64:
|
730 |
{ |
731 |
blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring; |
732 |
|
733 |
BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, XC_PAGE_SIZE); |
734 |
break;
|
735 |
} |
736 |
} |
737 |
|
738 |
xen_be_bind_evtchn(&blkdev->xendev); |
739 |
|
740 |
xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " |
741 |
"remote port %d, local port %d\n",
|
742 |
blkdev->xendev.protocol, blkdev->ring_ref, |
743 |
blkdev->xendev.remote_port, blkdev->xendev.local_port); |
744 |
return 0; |
745 |
} |
746 |
|
747 |
static void blk_disconnect(struct XenDevice *xendev) |
748 |
{ |
749 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
750 |
|
751 |
if (blkdev->bs) {
|
752 |
if (!blkdev->dinfo) {
|
753 |
/* close/delete only if we created it ourself */
|
754 |
bdrv_close(blkdev->bs); |
755 |
bdrv_detach_dev(blkdev->bs, blkdev); |
756 |
bdrv_delete(blkdev->bs); |
757 |
} |
758 |
blkdev->bs = NULL;
|
759 |
} |
760 |
xen_be_unbind_evtchn(&blkdev->xendev); |
761 |
|
762 |
if (blkdev->sring) {
|
763 |
xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1);
|
764 |
blkdev->cnt_map--; |
765 |
blkdev->sring = NULL;
|
766 |
} |
767 |
} |
768 |
|
769 |
static int blk_free(struct XenDevice *xendev) |
770 |
{ |
771 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
772 |
struct ioreq *ioreq;
|
773 |
|
774 |
if (blkdev->bs || blkdev->sring) {
|
775 |
blk_disconnect(xendev); |
776 |
} |
777 |
|
778 |
while (!QLIST_EMPTY(&blkdev->freelist)) {
|
779 |
ioreq = QLIST_FIRST(&blkdev->freelist); |
780 |
QLIST_REMOVE(ioreq, list); |
781 |
qemu_iovec_destroy(&ioreq->v); |
782 |
g_free(ioreq); |
783 |
} |
784 |
|
785 |
g_free(blkdev->params); |
786 |
g_free(blkdev->mode); |
787 |
g_free(blkdev->type); |
788 |
g_free(blkdev->dev); |
789 |
g_free(blkdev->devtype); |
790 |
qemu_bh_delete(blkdev->bh); |
791 |
return 0; |
792 |
} |
793 |
|
794 |
static void blk_event(struct XenDevice *xendev) |
795 |
{ |
796 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
797 |
|
798 |
qemu_bh_schedule(blkdev->bh); |
799 |
} |
800 |
|
801 |
struct XenDevOps xen_blkdev_ops = {
|
802 |
.size = sizeof(struct XenBlkDev), |
803 |
.flags = DEVOPS_FLAG_NEED_GNTDEV, |
804 |
.alloc = blk_alloc, |
805 |
.init = blk_init, |
806 |
.initialise = blk_connect, |
807 |
.disconnect = blk_disconnect, |
808 |
.event = blk_event, |
809 |
.free = blk_free, |
810 |
}; |