root / hw / block / xen_disk.c @ c0777fe1
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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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#include "hw/hw.h" |
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#include "hw/xen/xen_backend.h" |
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#include "xen_blkif.h" |
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#include "sysemu/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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struct PersistentGrant {
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void *page;
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struct XenBlkDev *blkdev;
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}; |
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typedef struct PersistentGrant PersistentGrant; |
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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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/* 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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int num_unmap;
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/* aio status */
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int aio_inflight;
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int aio_errors;
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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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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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bool directiosafe;
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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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/* Persistent grants extension */
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gboolean feature_persistent; |
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GTree *persistent_gnts; |
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unsigned int persistent_gnt_count; |
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unsigned int max_grants; |
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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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static void ioreq_reset(struct ioreq *ioreq) |
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{ |
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memset(&ioreq->req, 0, sizeof(ioreq->req)); |
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ioreq->status = 0;
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ioreq->start = 0;
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ioreq->presync = 0;
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ioreq->postsync = 0;
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ioreq->mapped = 0;
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memset(ioreq->domids, 0, sizeof(ioreq->domids)); |
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memset(ioreq->refs, 0, sizeof(ioreq->refs)); |
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ioreq->prot = 0;
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memset(ioreq->page, 0, sizeof(ioreq->page)); |
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ioreq->pages = NULL;
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ioreq->aio_inflight = 0;
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ioreq->aio_errors = 0;
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ioreq->blkdev = NULL;
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memset(&ioreq->list, 0, sizeof(ioreq->list)); |
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memset(&ioreq->acct, 0, sizeof(ioreq->acct)); |
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qemu_iovec_reset(&ioreq->v); |
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} |
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static gint int_cmp(gconstpointer a, gconstpointer b, gpointer user_data)
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{ |
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uint ua = GPOINTER_TO_UINT(a); |
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uint ub = GPOINTER_TO_UINT(b); |
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return (ua > ub) - (ua < ub);
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} |
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static void destroy_grant(gpointer pgnt) |
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{ |
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PersistentGrant *grant = pgnt; |
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XenGnttab gnt = grant->blkdev->xendev.gnttabdev; |
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if (xc_gnttab_munmap(gnt, grant->page, 1) != 0) { |
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xen_be_printf(&grant->blkdev->xendev, 0,
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"xc_gnttab_munmap failed: %s\n",
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strerror(errno)); |
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} |
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grant->blkdev->persistent_gnt_count--; |
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xen_be_printf(&grant->blkdev->xendev, 3,
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"unmapped grant %p\n", grant->page);
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g_free(grant); |
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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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} |
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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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} |
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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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QLIST_REMOVE(ioreq, list); |
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ioreq_reset(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_FLUSH_DISKCACHE:
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ioreq->presync = 1;
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if (!ioreq->req.nr_segments) {
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return 0; |
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} |
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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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} |
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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"); |
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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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err:
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ioreq->status = BLKIF_RSP_ERROR; |
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return -1; |
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} |
299 |
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static void ioreq_unmap(struct ioreq *ioreq) |
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{ |
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XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
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int i;
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if (ioreq->num_unmap == 0 || ioreq->mapped == 0) { |
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return;
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} |
308 |
if (batch_maps) {
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309 |
if (!ioreq->pages) {
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return;
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} |
312 |
if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->num_unmap) != 0) { |
313 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
314 |
strerror(errno)); |
315 |
} |
316 |
ioreq->blkdev->cnt_map -= ioreq->num_unmap; |
317 |
ioreq->pages = NULL;
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318 |
} else {
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for (i = 0; i < ioreq->num_unmap; i++) { |
320 |
if (!ioreq->page[i]) {
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continue;
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} |
323 |
if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0) { |
324 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
325 |
strerror(errno)); |
326 |
} |
327 |
ioreq->blkdev->cnt_map--; |
328 |
ioreq->page[i] = NULL;
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329 |
} |
330 |
} |
331 |
ioreq->mapped = 0;
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332 |
} |
333 |
|
334 |
static int ioreq_map(struct ioreq *ioreq) |
335 |
{ |
336 |
XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
337 |
uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
338 |
uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
339 |
void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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340 |
int i, j, new_maps = 0; |
341 |
PersistentGrant *grant; |
342 |
/* domids and refs variables will contain the information necessary
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343 |
* to map the grants that are needed to fulfill this request.
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344 |
*
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345 |
* After mapping the needed grants, the page array will contain the
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346 |
* memory address of each granted page in the order specified in ioreq
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347 |
* (disregarding if it's a persistent grant or not).
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348 |
*/
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349 |
|
350 |
if (ioreq->v.niov == 0 || ioreq->mapped == 1) { |
351 |
return 0; |
352 |
} |
353 |
if (ioreq->blkdev->feature_persistent) {
|
354 |
for (i = 0; i < ioreq->v.niov; i++) { |
355 |
grant = g_tree_lookup(ioreq->blkdev->persistent_gnts, |
356 |
GUINT_TO_POINTER(ioreq->refs[i])); |
357 |
|
358 |
if (grant != NULL) { |
359 |
page[i] = grant->page; |
360 |
xen_be_printf(&ioreq->blkdev->xendev, 3,
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361 |
"using persistent-grant %" PRIu32 "\n", |
362 |
ioreq->refs[i]); |
363 |
} else {
|
364 |
/* Add the grant to the list of grants that
|
365 |
* should be mapped
|
366 |
*/
|
367 |
domids[new_maps] = ioreq->domids[i]; |
368 |
refs[new_maps] = ioreq->refs[i]; |
369 |
page[i] = NULL;
|
370 |
new_maps++; |
371 |
} |
372 |
} |
373 |
/* Set the protection to RW, since grants may be reused later
|
374 |
* with a different protection than the one needed for this request
|
375 |
*/
|
376 |
ioreq->prot = PROT_WRITE | PROT_READ; |
377 |
} else {
|
378 |
/* All grants in the request should be mapped */
|
379 |
memcpy(refs, ioreq->refs, sizeof(refs));
|
380 |
memcpy(domids, ioreq->domids, sizeof(domids));
|
381 |
memset(page, 0, sizeof(page)); |
382 |
new_maps = ioreq->v.niov; |
383 |
} |
384 |
|
385 |
if (batch_maps && new_maps) {
|
386 |
ioreq->pages = xc_gnttab_map_grant_refs |
387 |
(gnt, new_maps, domids, refs, ioreq->prot); |
388 |
if (ioreq->pages == NULL) { |
389 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
|
390 |
"can't map %d grant refs (%s, %d maps)\n",
|
391 |
new_maps, strerror(errno), ioreq->blkdev->cnt_map); |
392 |
return -1; |
393 |
} |
394 |
for (i = 0, j = 0; i < ioreq->v.niov; i++) { |
395 |
if (page[i] == NULL) { |
396 |
page[i] = ioreq->pages + (j++) * XC_PAGE_SIZE; |
397 |
} |
398 |
} |
399 |
ioreq->blkdev->cnt_map += new_maps; |
400 |
} else if (new_maps) { |
401 |
for (i = 0; i < new_maps; i++) { |
402 |
ioreq->page[i] = xc_gnttab_map_grant_ref |
403 |
(gnt, domids[i], refs[i], ioreq->prot); |
404 |
if (ioreq->page[i] == NULL) { |
405 |
xen_be_printf(&ioreq->blkdev->xendev, 0,
|
406 |
"can't map grant ref %d (%s, %d maps)\n",
|
407 |
refs[i], strerror(errno), ioreq->blkdev->cnt_map); |
408 |
ioreq_unmap(ioreq); |
409 |
return -1; |
410 |
} |
411 |
ioreq->blkdev->cnt_map++; |
412 |
} |
413 |
for (i = 0, j = 0; i < ioreq->v.niov; i++) { |
414 |
if (page[i] == NULL) { |
415 |
page[i] = ioreq->page[j++]; |
416 |
} |
417 |
} |
418 |
} |
419 |
if (ioreq->blkdev->feature_persistent) {
|
420 |
while ((ioreq->blkdev->persistent_gnt_count < ioreq->blkdev->max_grants)
|
421 |
&& new_maps) { |
422 |
/* Go through the list of newly mapped grants and add as many
|
423 |
* as possible to the list of persistently mapped grants.
|
424 |
*
|
425 |
* Since we start at the end of ioreq->page(s), we only need
|
426 |
* to decrease new_maps to prevent this granted pages from
|
427 |
* being unmapped in ioreq_unmap.
|
428 |
*/
|
429 |
grant = g_malloc0(sizeof(*grant));
|
430 |
new_maps--; |
431 |
if (batch_maps) {
|
432 |
grant->page = ioreq->pages + (new_maps) * XC_PAGE_SIZE; |
433 |
} else {
|
434 |
grant->page = ioreq->page[new_maps]; |
435 |
} |
436 |
grant->blkdev = ioreq->blkdev; |
437 |
xen_be_printf(&ioreq->blkdev->xendev, 3,
|
438 |
"adding grant %" PRIu32 " page: %p\n", |
439 |
refs[new_maps], grant->page); |
440 |
g_tree_insert(ioreq->blkdev->persistent_gnts, |
441 |
GUINT_TO_POINTER(refs[new_maps]), |
442 |
grant); |
443 |
ioreq->blkdev->persistent_gnt_count++; |
444 |
} |
445 |
} |
446 |
for (i = 0; i < ioreq->v.niov; i++) { |
447 |
ioreq->v.iov[i].iov_base += (uintptr_t)page[i]; |
448 |
} |
449 |
ioreq->mapped = 1;
|
450 |
ioreq->num_unmap = new_maps; |
451 |
return 0; |
452 |
} |
453 |
|
454 |
static int ioreq_runio_qemu_aio(struct ioreq *ioreq); |
455 |
|
456 |
static void qemu_aio_complete(void *opaque, int ret) |
457 |
{ |
458 |
struct ioreq *ioreq = opaque;
|
459 |
|
460 |
if (ret != 0) { |
461 |
xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n", |
462 |
ioreq->req.operation == BLKIF_OP_READ ? "read" : "write"); |
463 |
ioreq->aio_errors++; |
464 |
} |
465 |
|
466 |
ioreq->aio_inflight--; |
467 |
if (ioreq->presync) {
|
468 |
ioreq->presync = 0;
|
469 |
ioreq_runio_qemu_aio(ioreq); |
470 |
return;
|
471 |
} |
472 |
if (ioreq->aio_inflight > 0) { |
473 |
return;
|
474 |
} |
475 |
if (ioreq->postsync) {
|
476 |
ioreq->postsync = 0;
|
477 |
ioreq->aio_inflight++; |
478 |
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq); |
479 |
return;
|
480 |
} |
481 |
|
482 |
ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY; |
483 |
ioreq_unmap(ioreq); |
484 |
ioreq_finish(ioreq); |
485 |
bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct); |
486 |
qemu_bh_schedule(ioreq->blkdev->bh); |
487 |
} |
488 |
|
489 |
static int ioreq_runio_qemu_aio(struct ioreq *ioreq) |
490 |
{ |
491 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
492 |
|
493 |
if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) { |
494 |
goto err_no_map;
|
495 |
} |
496 |
|
497 |
ioreq->aio_inflight++; |
498 |
if (ioreq->presync) {
|
499 |
bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq); |
500 |
return 0; |
501 |
} |
502 |
|
503 |
switch (ioreq->req.operation) {
|
504 |
case BLKIF_OP_READ:
|
505 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_READ); |
506 |
ioreq->aio_inflight++; |
507 |
bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE, |
508 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
509 |
qemu_aio_complete, ioreq); |
510 |
break;
|
511 |
case BLKIF_OP_WRITE:
|
512 |
case BLKIF_OP_FLUSH_DISKCACHE:
|
513 |
if (!ioreq->req.nr_segments) {
|
514 |
break;
|
515 |
} |
516 |
|
517 |
bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_WRITE); |
518 |
ioreq->aio_inflight++; |
519 |
bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE, |
520 |
&ioreq->v, ioreq->v.size / BLOCK_SIZE, |
521 |
qemu_aio_complete, ioreq); |
522 |
break;
|
523 |
default:
|
524 |
/* unknown operation (shouldn't happen -- parse catches this) */
|
525 |
goto err;
|
526 |
} |
527 |
|
528 |
qemu_aio_complete(ioreq, 0);
|
529 |
|
530 |
return 0; |
531 |
|
532 |
err:
|
533 |
ioreq_unmap(ioreq); |
534 |
err_no_map:
|
535 |
ioreq_finish(ioreq); |
536 |
ioreq->status = BLKIF_RSP_ERROR; |
537 |
return -1; |
538 |
} |
539 |
|
540 |
static int blk_send_response_one(struct ioreq *ioreq) |
541 |
{ |
542 |
struct XenBlkDev *blkdev = ioreq->blkdev;
|
543 |
int send_notify = 0; |
544 |
int have_requests = 0; |
545 |
blkif_response_t resp; |
546 |
void *dst;
|
547 |
|
548 |
resp.id = ioreq->req.id; |
549 |
resp.operation = ioreq->req.operation; |
550 |
resp.status = ioreq->status; |
551 |
|
552 |
/* Place on the response ring for the relevant domain. */
|
553 |
switch (blkdev->protocol) {
|
554 |
case BLKIF_PROTOCOL_NATIVE:
|
555 |
dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt); |
556 |
break;
|
557 |
case BLKIF_PROTOCOL_X86_32:
|
558 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part, |
559 |
blkdev->rings.x86_32_part.rsp_prod_pvt); |
560 |
break;
|
561 |
case BLKIF_PROTOCOL_X86_64:
|
562 |
dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part, |
563 |
blkdev->rings.x86_64_part.rsp_prod_pvt); |
564 |
break;
|
565 |
default:
|
566 |
dst = NULL;
|
567 |
} |
568 |
memcpy(dst, &resp, sizeof(resp));
|
569 |
blkdev->rings.common.rsp_prod_pvt++; |
570 |
|
571 |
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify); |
572 |
if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
|
573 |
/*
|
574 |
* Tail check for pending requests. Allows frontend to avoid
|
575 |
* notifications if requests are already in flight (lower
|
576 |
* overheads and promotes batching).
|
577 |
*/
|
578 |
RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests); |
579 |
} else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) { |
580 |
have_requests = 1;
|
581 |
} |
582 |
|
583 |
if (have_requests) {
|
584 |
blkdev->more_work++; |
585 |
} |
586 |
return send_notify;
|
587 |
} |
588 |
|
589 |
/* walk finished list, send outstanding responses, free requests */
|
590 |
static void blk_send_response_all(struct XenBlkDev *blkdev) |
591 |
{ |
592 |
struct ioreq *ioreq;
|
593 |
int send_notify = 0; |
594 |
|
595 |
while (!QLIST_EMPTY(&blkdev->finished)) {
|
596 |
ioreq = QLIST_FIRST(&blkdev->finished); |
597 |
send_notify += blk_send_response_one(ioreq); |
598 |
ioreq_release(ioreq, true);
|
599 |
} |
600 |
if (send_notify) {
|
601 |
xen_be_send_notify(&blkdev->xendev); |
602 |
} |
603 |
} |
604 |
|
605 |
static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc) |
606 |
{ |
607 |
switch (blkdev->protocol) {
|
608 |
case BLKIF_PROTOCOL_NATIVE:
|
609 |
memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc), |
610 |
sizeof(ioreq->req));
|
611 |
break;
|
612 |
case BLKIF_PROTOCOL_X86_32:
|
613 |
blkif_get_x86_32_req(&ioreq->req, |
614 |
RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc)); |
615 |
break;
|
616 |
case BLKIF_PROTOCOL_X86_64:
|
617 |
blkif_get_x86_64_req(&ioreq->req, |
618 |
RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc)); |
619 |
break;
|
620 |
} |
621 |
return 0; |
622 |
} |
623 |
|
624 |
static void blk_handle_requests(struct XenBlkDev *blkdev) |
625 |
{ |
626 |
RING_IDX rc, rp; |
627 |
struct ioreq *ioreq;
|
628 |
|
629 |
blkdev->more_work = 0;
|
630 |
|
631 |
rc = blkdev->rings.common.req_cons; |
632 |
rp = blkdev->rings.common.sring->req_prod; |
633 |
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
|
634 |
|
635 |
blk_send_response_all(blkdev); |
636 |
while (rc != rp) {
|
637 |
/* pull request from ring */
|
638 |
if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
|
639 |
break;
|
640 |
} |
641 |
ioreq = ioreq_start(blkdev); |
642 |
if (ioreq == NULL) { |
643 |
blkdev->more_work++; |
644 |
break;
|
645 |
} |
646 |
blk_get_request(blkdev, ioreq, rc); |
647 |
blkdev->rings.common.req_cons = ++rc; |
648 |
|
649 |
/* parse them */
|
650 |
if (ioreq_parse(ioreq) != 0) { |
651 |
if (blk_send_response_one(ioreq)) {
|
652 |
xen_be_send_notify(&blkdev->xendev); |
653 |
} |
654 |
ioreq_release(ioreq, false);
|
655 |
continue;
|
656 |
} |
657 |
|
658 |
ioreq_runio_qemu_aio(ioreq); |
659 |
} |
660 |
|
661 |
if (blkdev->more_work && blkdev->requests_inflight < max_requests) {
|
662 |
qemu_bh_schedule(blkdev->bh); |
663 |
} |
664 |
} |
665 |
|
666 |
/* ------------------------------------------------------------- */
|
667 |
|
668 |
static void blk_bh(void *opaque) |
669 |
{ |
670 |
struct XenBlkDev *blkdev = opaque;
|
671 |
blk_handle_requests(blkdev); |
672 |
} |
673 |
|
674 |
/*
|
675 |
* We need to account for the grant allocations requiring contiguous
|
676 |
* chunks; the worst case number would be
|
677 |
* max_req * max_seg + (max_req - 1) * (max_seg - 1) + 1,
|
678 |
* but in order to keep things simple just use
|
679 |
* 2 * max_req * max_seg.
|
680 |
*/
|
681 |
#define MAX_GRANTS(max_req, max_seg) (2 * (max_req) * (max_seg)) |
682 |
|
683 |
static void blk_alloc(struct XenDevice *xendev) |
684 |
{ |
685 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
686 |
|
687 |
QLIST_INIT(&blkdev->inflight); |
688 |
QLIST_INIT(&blkdev->finished); |
689 |
QLIST_INIT(&blkdev->freelist); |
690 |
blkdev->bh = qemu_bh_new(blk_bh, blkdev); |
691 |
if (xen_mode != XEN_EMULATE) {
|
692 |
batch_maps = 1;
|
693 |
} |
694 |
if (xc_gnttab_set_max_grants(xendev->gnttabdev,
|
695 |
MAX_GRANTS(max_requests, BLKIF_MAX_SEGMENTS_PER_REQUEST)) < 0) {
|
696 |
xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n", |
697 |
strerror(errno)); |
698 |
} |
699 |
} |
700 |
|
701 |
static int blk_init(struct XenDevice *xendev) |
702 |
{ |
703 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
704 |
int info = 0; |
705 |
char *directiosafe = NULL; |
706 |
|
707 |
/* read xenstore entries */
|
708 |
if (blkdev->params == NULL) { |
709 |
char *h = NULL; |
710 |
blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params");
|
711 |
if (blkdev->params != NULL) { |
712 |
h = strchr(blkdev->params, ':');
|
713 |
} |
714 |
if (h != NULL) { |
715 |
blkdev->fileproto = blkdev->params; |
716 |
blkdev->filename = h+1;
|
717 |
*h = 0;
|
718 |
} else {
|
719 |
blkdev->fileproto = "<unset>";
|
720 |
blkdev->filename = blkdev->params; |
721 |
} |
722 |
} |
723 |
if (!strcmp("aio", blkdev->fileproto)) { |
724 |
blkdev->fileproto = "raw";
|
725 |
} |
726 |
if (blkdev->mode == NULL) { |
727 |
blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
|
728 |
} |
729 |
if (blkdev->type == NULL) { |
730 |
blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type");
|
731 |
} |
732 |
if (blkdev->dev == NULL) { |
733 |
blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev");
|
734 |
} |
735 |
if (blkdev->devtype == NULL) { |
736 |
blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type");
|
737 |
} |
738 |
directiosafe = xenstore_read_be_str(&blkdev->xendev, "direct-io-safe");
|
739 |
blkdev->directiosafe = (directiosafe && atoi(directiosafe)); |
740 |
|
741 |
/* do we have all we need? */
|
742 |
if (blkdev->params == NULL || |
743 |
blkdev->mode == NULL ||
|
744 |
blkdev->type == NULL ||
|
745 |
blkdev->dev == NULL) {
|
746 |
goto out_error;
|
747 |
} |
748 |
|
749 |
/* read-only ? */
|
750 |
if (strcmp(blkdev->mode, "w")) { |
751 |
info |= VDISK_READONLY; |
752 |
} |
753 |
|
754 |
/* cdrom ? */
|
755 |
if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) { |
756 |
info |= VDISK_CDROM; |
757 |
} |
758 |
|
759 |
blkdev->file_blk = BLOCK_SIZE; |
760 |
|
761 |
/* fill info
|
762 |
* blk_connect supplies sector-size and sectors
|
763 |
*/
|
764 |
xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1); |
765 |
xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1); |
766 |
xenstore_write_be_int(&blkdev->xendev, "info", info);
|
767 |
|
768 |
g_free(directiosafe); |
769 |
return 0; |
770 |
|
771 |
out_error:
|
772 |
g_free(blkdev->params); |
773 |
blkdev->params = NULL;
|
774 |
g_free(blkdev->mode); |
775 |
blkdev->mode = NULL;
|
776 |
g_free(blkdev->type); |
777 |
blkdev->type = NULL;
|
778 |
g_free(blkdev->dev); |
779 |
blkdev->dev = NULL;
|
780 |
g_free(blkdev->devtype); |
781 |
blkdev->devtype = NULL;
|
782 |
g_free(directiosafe); |
783 |
blkdev->directiosafe = false;
|
784 |
return -1; |
785 |
} |
786 |
|
787 |
static int blk_connect(struct XenDevice *xendev) |
788 |
{ |
789 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
790 |
int pers, index, qflags;
|
791 |
bool readonly = true; |
792 |
|
793 |
/* read-only ? */
|
794 |
if (blkdev->directiosafe) {
|
795 |
qflags = BDRV_O_NOCACHE | BDRV_O_NATIVE_AIO; |
796 |
} else {
|
797 |
qflags = BDRV_O_CACHE_WB; |
798 |
} |
799 |
if (strcmp(blkdev->mode, "w") == 0) { |
800 |
qflags |= BDRV_O_RDWR; |
801 |
readonly = false;
|
802 |
} |
803 |
|
804 |
/* init qemu block driver */
|
805 |
index = (blkdev->xendev.dev - 202 * 256) / 16; |
806 |
blkdev->dinfo = drive_get(IF_XEN, 0, index);
|
807 |
if (!blkdev->dinfo) {
|
808 |
/* setup via xenbus -> create new block driver instance */
|
809 |
xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n"); |
810 |
blkdev->bs = bdrv_new(blkdev->dev); |
811 |
if (blkdev->bs) {
|
812 |
BlockDriver *drv = bdrv_find_whitelisted_format(blkdev->fileproto, |
813 |
readonly); |
814 |
if (bdrv_open(blkdev->bs,
|
815 |
blkdev->filename, NULL, qflags, drv) != 0) { |
816 |
bdrv_unref(blkdev->bs); |
817 |
blkdev->bs = NULL;
|
818 |
} |
819 |
} |
820 |
if (!blkdev->bs) {
|
821 |
return -1; |
822 |
} |
823 |
} else {
|
824 |
/* setup via qemu cmdline -> already setup for us */
|
825 |
xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n"); |
826 |
blkdev->bs = blkdev->dinfo->bdrv; |
827 |
/* blkdev->bs is not create by us, we get a reference
|
828 |
* so we can bdrv_unref() unconditionally */
|
829 |
bdrv_ref(blkdev->bs); |
830 |
} |
831 |
bdrv_attach_dev_nofail(blkdev->bs, blkdev); |
832 |
blkdev->file_size = bdrv_getlength(blkdev->bs); |
833 |
if (blkdev->file_size < 0) { |
834 |
xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n", |
835 |
(int)blkdev->file_size, strerror(-blkdev->file_size),
|
836 |
bdrv_get_format_name(blkdev->bs) ?: "-");
|
837 |
blkdev->file_size = 0;
|
838 |
} |
839 |
|
840 |
xen_be_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\"," |
841 |
" size %" PRId64 " (%" PRId64 " MB)\n", |
842 |
blkdev->type, blkdev->fileproto, blkdev->filename, |
843 |
blkdev->file_size, blkdev->file_size >> 20);
|
844 |
|
845 |
/* Fill in number of sector size and number of sectors */
|
846 |
xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk);
|
847 |
xenstore_write_be_int64(&blkdev->xendev, "sectors",
|
848 |
blkdev->file_size / blkdev->file_blk); |
849 |
|
850 |
if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) { |
851 |
return -1; |
852 |
} |
853 |
if (xenstore_read_fe_int(&blkdev->xendev, "event-channel", |
854 |
&blkdev->xendev.remote_port) == -1) {
|
855 |
return -1; |
856 |
} |
857 |
if (xenstore_read_fe_int(&blkdev->xendev, "feature-persistent", &pers)) { |
858 |
blkdev->feature_persistent = FALSE; |
859 |
} else {
|
860 |
blkdev->feature_persistent = !!pers; |
861 |
} |
862 |
|
863 |
blkdev->protocol = BLKIF_PROTOCOL_NATIVE; |
864 |
if (blkdev->xendev.protocol) {
|
865 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { |
866 |
blkdev->protocol = BLKIF_PROTOCOL_X86_32; |
867 |
} |
868 |
if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { |
869 |
blkdev->protocol = BLKIF_PROTOCOL_X86_64; |
870 |
} |
871 |
} |
872 |
|
873 |
blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev, |
874 |
blkdev->xendev.dom, |
875 |
blkdev->ring_ref, |
876 |
PROT_READ | PROT_WRITE); |
877 |
if (!blkdev->sring) {
|
878 |
return -1; |
879 |
} |
880 |
blkdev->cnt_map++; |
881 |
|
882 |
switch (blkdev->protocol) {
|
883 |
case BLKIF_PROTOCOL_NATIVE:
|
884 |
{ |
885 |
blkif_sring_t *sring_native = blkdev->sring; |
886 |
BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_SIZE); |
887 |
break;
|
888 |
} |
889 |
case BLKIF_PROTOCOL_X86_32:
|
890 |
{ |
891 |
blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring; |
892 |
|
893 |
BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, XC_PAGE_SIZE); |
894 |
break;
|
895 |
} |
896 |
case BLKIF_PROTOCOL_X86_64:
|
897 |
{ |
898 |
blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring; |
899 |
|
900 |
BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, XC_PAGE_SIZE); |
901 |
break;
|
902 |
} |
903 |
} |
904 |
|
905 |
if (blkdev->feature_persistent) {
|
906 |
/* Init persistent grants */
|
907 |
blkdev->max_grants = max_requests * BLKIF_MAX_SEGMENTS_PER_REQUEST; |
908 |
blkdev->persistent_gnts = g_tree_new_full((GCompareDataFunc)int_cmp, |
909 |
NULL, NULL, |
910 |
(GDestroyNotify)destroy_grant); |
911 |
blkdev->persistent_gnt_count = 0;
|
912 |
} |
913 |
|
914 |
xen_be_bind_evtchn(&blkdev->xendev); |
915 |
|
916 |
xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " |
917 |
"remote port %d, local port %d\n",
|
918 |
blkdev->xendev.protocol, blkdev->ring_ref, |
919 |
blkdev->xendev.remote_port, blkdev->xendev.local_port); |
920 |
return 0; |
921 |
} |
922 |
|
923 |
static void blk_disconnect(struct XenDevice *xendev) |
924 |
{ |
925 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
926 |
|
927 |
if (blkdev->bs) {
|
928 |
bdrv_detach_dev(blkdev->bs, blkdev); |
929 |
bdrv_unref(blkdev->bs); |
930 |
blkdev->bs = NULL;
|
931 |
} |
932 |
xen_be_unbind_evtchn(&blkdev->xendev); |
933 |
|
934 |
if (blkdev->sring) {
|
935 |
xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1);
|
936 |
blkdev->cnt_map--; |
937 |
blkdev->sring = NULL;
|
938 |
} |
939 |
} |
940 |
|
941 |
static int blk_free(struct XenDevice *xendev) |
942 |
{ |
943 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
944 |
struct ioreq *ioreq;
|
945 |
|
946 |
if (blkdev->bs || blkdev->sring) {
|
947 |
blk_disconnect(xendev); |
948 |
} |
949 |
|
950 |
/* Free persistent grants */
|
951 |
if (blkdev->feature_persistent) {
|
952 |
g_tree_destroy(blkdev->persistent_gnts); |
953 |
} |
954 |
|
955 |
while (!QLIST_EMPTY(&blkdev->freelist)) {
|
956 |
ioreq = QLIST_FIRST(&blkdev->freelist); |
957 |
QLIST_REMOVE(ioreq, list); |
958 |
qemu_iovec_destroy(&ioreq->v); |
959 |
g_free(ioreq); |
960 |
} |
961 |
|
962 |
g_free(blkdev->params); |
963 |
g_free(blkdev->mode); |
964 |
g_free(blkdev->type); |
965 |
g_free(blkdev->dev); |
966 |
g_free(blkdev->devtype); |
967 |
qemu_bh_delete(blkdev->bh); |
968 |
return 0; |
969 |
} |
970 |
|
971 |
static void blk_event(struct XenDevice *xendev) |
972 |
{ |
973 |
struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
974 |
|
975 |
qemu_bh_schedule(blkdev->bh); |
976 |
} |
977 |
|
978 |
struct XenDevOps xen_blkdev_ops = {
|
979 |
.size = sizeof(struct XenBlkDev), |
980 |
.flags = DEVOPS_FLAG_NEED_GNTDEV, |
981 |
.alloc = blk_alloc, |
982 |
.init = blk_init, |
983 |
.initialise = blk_connect, |
984 |
.disconnect = blk_disconnect, |
985 |
.event = blk_event, |
986 |
.free = blk_free, |
987 |
}; |