| /* |
| * 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/>. |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <stdarg.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <signal.h> |
| #include <inttypes.h> |
| #include <time.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| #include <sys/ioctl.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/mman.h> |
| #include <sys/uio.h> |
| |
| #include <xs.h> |
| #include <xenctrl.h> |
| #include <xen/io/xenbus.h> |
| |
| #include "hw.h" |
| #include "block_int.h" |
| #include "qemu-char.h" |
| #include "xen_blkif.h" |
| #include "xen_backend.h" |
| #include "blockdev.h" |
| |
| /* ------------------------------------------------------------- */ |
| |
| static int syncwrite = 0; |
| static int batch_maps = 0; |
| |
| static int max_requests = 32; |
| static int use_aio = 1; |
| |
| /* ------------------------------------------------------------- */ |
| |
| #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; |
| int presync; |
| int postsync; |
| |
| /* grant mapping */ |
| uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
| uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
| int prot; |
| void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
| void *pages; |
| |
| /* aio status */ |
| int aio_inflight; |
| int aio_errors; |
| |
| struct XenBlkDev *blkdev; |
| QLIST_ENTRY(ioreq) list; |
| }; |
| |
| struct XenBlkDev { |
| struct XenDevice xendev; /* must be first */ |
| char *params; |
| char *mode; |
| char *type; |
| char *dev; |
| char *devtype; |
| const char *fileproto; |
| const char *filename; |
| int ring_ref; |
| void *sring; |
| int64_t file_blk; |
| int64_t file_size; |
| int protocol; |
| blkif_back_rings_t rings; |
| int more_work; |
| int cnt_map; |
| |
| /* 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; |
| |
| /* qemu block driver */ |
| DriveInfo *dinfo; |
| BlockDriverState *bs; |
| QEMUBH *bh; |
| }; |
| |
| /* ------------------------------------------------------------- */ |
| |
| static struct ioreq *ioreq_start(struct XenBlkDev *blkdev) |
| { |
| struct ioreq *ioreq = NULL; |
| |
| if (QLIST_EMPTY(&blkdev->freelist)) { |
| if (blkdev->requests_total >= max_requests) { |
| goto out; |
| } |
| /* allocate new struct */ |
| ioreq = qemu_mallocz(sizeof(*ioreq)); |
| ioreq->blkdev = blkdev; |
| blkdev->requests_total++; |
| qemu_iovec_init(&ioreq->v, BLKIF_MAX_SEGMENTS_PER_REQUEST); |
| } else { |
| /* get one from freelist */ |
| ioreq = QLIST_FIRST(&blkdev->freelist); |
| QLIST_REMOVE(ioreq, list); |
| qemu_iovec_reset(&ioreq->v); |
| } |
| 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) |
| { |
| struct XenBlkDev *blkdev = ioreq->blkdev; |
| |
| QLIST_REMOVE(ioreq, list); |
| memset(ioreq, 0, sizeof(*ioreq)); |
| ioreq->blkdev = blkdev; |
| QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list); |
| blkdev->requests_finished--; |
| } |
| |
| /* |
| * translate request into iovec + start offset |
| * do sanity checks along the way |
| */ |
| static int ioreq_parse(struct ioreq *ioreq) |
| { |
| struct XenBlkDev *blkdev = ioreq->blkdev; |
| uintptr_t mem; |
| size_t len; |
| int i; |
| |
| xen_be_printf(&blkdev->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: |
| ioreq->prot = PROT_WRITE; /* to memory */ |
| break; |
| case BLKIF_OP_WRITE_BARRIER: |
| if (!ioreq->req.nr_segments) { |
| ioreq->presync = 1; |
| return 0; |
| } |
| if (!syncwrite) { |
| ioreq->presync = ioreq->postsync = 1; |
| } |
| /* fall through */ |
| case BLKIF_OP_WRITE: |
| ioreq->prot = PROT_READ; /* from memory */ |
| if (syncwrite) { |
| ioreq->postsync = 1; |
| } |
| break; |
| default: |
| xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n", |
| ioreq->req.operation); |
| goto err; |
| }; |
| |
| if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') { |
| xen_be_printf(&blkdev->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_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n"); |
| goto err; |
| } |
| if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) { |
| xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n"); |
| goto err; |
| } |
| if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) { |
| xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n"); |
| goto err; |
| } |
| |
| ioreq->domids[i] = blkdev->xendev.dom; |
| ioreq->refs[i] = ioreq->req.seg[i].gref; |
| |
| mem = ioreq->req.seg[i].first_sect * blkdev->file_blk; |
| len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk; |
| qemu_iovec_add(&ioreq->v, (void*)mem, len); |
| } |
| if (ioreq->start + ioreq->v.size > blkdev->file_size) { |
| xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n"); |
| goto err; |
| } |
| return 0; |
| |
| err: |
| ioreq->status = BLKIF_RSP_ERROR; |
| return -1; |
| } |
| |
| static void ioreq_unmap(struct ioreq *ioreq) |
| { |
| XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
| int i; |
| |
| if (ioreq->v.niov == 0) { |
| return; |
| } |
| if (batch_maps) { |
| if (!ioreq->pages) { |
| return; |
| } |
| if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->v.niov) != 0) { |
| xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
| strerror(errno)); |
| } |
| ioreq->blkdev->cnt_map -= ioreq->v.niov; |
| ioreq->pages = NULL; |
| } else { |
| for (i = 0; i < ioreq->v.niov; i++) { |
| if (!ioreq->page[i]) { |
| continue; |
| } |
| if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0) { |
| xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n", |
| strerror(errno)); |
| } |
| ioreq->blkdev->cnt_map--; |
| ioreq->page[i] = NULL; |
| } |
| } |
| } |
| |
| static int ioreq_map(struct ioreq *ioreq) |
| { |
| XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev; |
| int i; |
| |
| if (ioreq->v.niov == 0) { |
| return 0; |
| } |
| if (batch_maps) { |
| ioreq->pages = xc_gnttab_map_grant_refs |
| (gnt, ioreq->v.niov, ioreq->domids, ioreq->refs, ioreq->prot); |
| if (ioreq->pages == NULL) { |
| xen_be_printf(&ioreq->blkdev->xendev, 0, |
| "can't map %d grant refs (%s, %d maps)\n", |
| ioreq->v.niov, strerror(errno), ioreq->blkdev->cnt_map); |
| return -1; |
| } |
| for (i = 0; i < ioreq->v.niov; i++) { |
| ioreq->v.iov[i].iov_base = ioreq->pages + i * XC_PAGE_SIZE + |
| (uintptr_t)ioreq->v.iov[i].iov_base; |
| } |
| ioreq->blkdev->cnt_map += ioreq->v.niov; |
| } else { |
| for (i = 0; i < ioreq->v.niov; i++) { |
| ioreq->page[i] = xc_gnttab_map_grant_ref |
| (gnt, ioreq->domids[i], ioreq->refs[i], ioreq->prot); |
| if (ioreq->page[i] == NULL) { |
| xen_be_printf(&ioreq->blkdev->xendev, 0, |
| "can't map grant ref %d (%s, %d maps)\n", |
| ioreq->refs[i], strerror(errno), ioreq->blkdev->cnt_map); |
| ioreq_unmap(ioreq); |
| return -1; |
| } |
| ioreq->v.iov[i].iov_base = ioreq->page[i] + (uintptr_t)ioreq->v.iov[i].iov_base; |
| ioreq->blkdev->cnt_map++; |
| } |
| } |
| return 0; |
| } |
| |
| static int ioreq_runio_qemu_sync(struct ioreq *ioreq) |
| { |
| struct XenBlkDev *blkdev = ioreq->blkdev; |
| int i, rc; |
| off_t pos; |
| |
| if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) { |
| goto err_no_map; |
| } |
| if (ioreq->presync) { |
| bdrv_flush(blkdev->bs); |
| } |
| |
| switch (ioreq->req.operation) { |
| case BLKIF_OP_READ: |
| pos = ioreq->start; |
| for (i = 0; i < ioreq->v.niov; i++) { |
| rc = bdrv_read(blkdev->bs, pos / BLOCK_SIZE, |
| ioreq->v.iov[i].iov_base, |
| ioreq->v.iov[i].iov_len / BLOCK_SIZE); |
| if (rc != 0) { |
| xen_be_printf(&blkdev->xendev, 0, "rd I/O error (%p, len %zd)\n", |
| ioreq->v.iov[i].iov_base, |
| ioreq->v.iov[i].iov_len); |
| goto err; |
| } |
| pos += ioreq->v.iov[i].iov_len; |
| } |
| break; |
| case BLKIF_OP_WRITE: |
| case BLKIF_OP_WRITE_BARRIER: |
| if (!ioreq->req.nr_segments) { |
| break; |
| } |
| pos = ioreq->start; |
| for (i = 0; i < ioreq->v.niov; i++) { |
| rc = bdrv_write(blkdev->bs, pos / BLOCK_SIZE, |
| ioreq->v.iov[i].iov_base, |
| ioreq->v.iov[i].iov_len / BLOCK_SIZE); |
| if (rc != 0) { |
| xen_be_printf(&blkdev->xendev, 0, "wr I/O error (%p, len %zd)\n", |
| ioreq->v.iov[i].iov_base, |
| ioreq->v.iov[i].iov_len); |
| goto err; |
| } |
| pos += ioreq->v.iov[i].iov_len; |
| } |
| break; |
| default: |
| /* unknown operation (shouldn't happen -- parse catches this) */ |
| goto err; |
| } |
| |
| if (ioreq->postsync) { |
| bdrv_flush(blkdev->bs); |
| } |
| ioreq->status = BLKIF_RSP_OKAY; |
| |
| ioreq_unmap(ioreq); |
| ioreq_finish(ioreq); |
| return 0; |
| |
| err: |
| ioreq_unmap(ioreq); |
| err_no_map: |
| ioreq_finish(ioreq); |
| ioreq->status = BLKIF_RSP_ERROR; |
| return -1; |
| } |
| |
| static void qemu_aio_complete(void *opaque, int ret) |
| { |
| struct ioreq *ioreq = opaque; |
| |
| if (ret != 0) { |
| xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n", |
| ioreq->req.operation == BLKIF_OP_READ ? "read" : "write"); |
| ioreq->aio_errors++; |
| } |
| |
| ioreq->aio_inflight--; |
| if (ioreq->aio_inflight > 0) { |
| return; |
| } |
| |
| ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY; |
| ioreq_unmap(ioreq); |
| ioreq_finish(ioreq); |
| qemu_bh_schedule(ioreq->blkdev->bh); |
| } |
| |
| static int ioreq_runio_qemu_aio(struct ioreq *ioreq) |
| { |
| struct XenBlkDev *blkdev = ioreq->blkdev; |
| |
| if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) { |
| goto err_no_map; |
| } |
| |
| ioreq->aio_inflight++; |
| if (ioreq->presync) { |
| bdrv_flush(blkdev->bs); /* FIXME: aio_flush() ??? */ |
| } |
| |
| switch (ioreq->req.operation) { |
| case BLKIF_OP_READ: |
| ioreq->aio_inflight++; |
| bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE, |
| &ioreq->v, ioreq->v.size / BLOCK_SIZE, |
| qemu_aio_complete, ioreq); |
| break; |
| case BLKIF_OP_WRITE: |
| case BLKIF_OP_WRITE_BARRIER: |
| if (!ioreq->req.nr_segments) { |
| break; |
| } |
| ioreq->aio_inflight++; |
| bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE, |
| &ioreq->v, ioreq->v.size / BLOCK_SIZE, |
| qemu_aio_complete, ioreq); |
| break; |
| default: |
| /* unknown operation (shouldn't happen -- parse catches this) */ |
| goto err; |
| } |
| |
| if (ioreq->postsync) { |
| bdrv_flush(blkdev->bs); /* FIXME: aio_flush() ??? */ |
| } |
| qemu_aio_complete(ioreq, 0); |
| |
| return 0; |
| |
| err: |
| ioreq_unmap(ioreq); |
| err_no_map: |
| 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; |
| void *dst; |
| |
| resp.id = ioreq->req.id; |
| resp.operation = ioreq->req.operation; |
| resp.status = ioreq->status; |
| |
| /* Place on the response ring for the relevant domain. */ |
| switch (blkdev->protocol) { |
| case BLKIF_PROTOCOL_NATIVE: |
| dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt); |
| break; |
| case BLKIF_PROTOCOL_X86_32: |
| dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part, |
| blkdev->rings.x86_32_part.rsp_prod_pvt); |
| break; |
| case BLKIF_PROTOCOL_X86_64: |
| dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part, |
| blkdev->rings.x86_64_part.rsp_prod_pvt); |
| break; |
| default: |
| dst = NULL; |
| } |
| memcpy(dst, &resp, sizeof(resp)); |
| 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); |
| } |
| if (send_notify) { |
| xen_be_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; |
| } |
| 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'. */ |
| |
| if (use_aio) { |
| 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) { |
| if (blk_send_response_one(ioreq)) { |
| xen_be_send_notify(&blkdev->xendev); |
| } |
| ioreq_release(ioreq); |
| continue; |
| } |
| |
| if (use_aio) { |
| /* run i/o in aio mode */ |
| ioreq_runio_qemu_aio(ioreq); |
| } else { |
| /* run i/o in sync mode */ |
| ioreq_runio_qemu_sync(ioreq); |
| } |
| } |
| if (!use_aio) { |
| blk_send_response_all(blkdev); |
| } |
| |
| if (blkdev->more_work && blkdev->requests_inflight < max_requests) { |
| qemu_bh_schedule(blkdev->bh); |
| } |
| } |
| |
| /* ------------------------------------------------------------- */ |
| |
| static void blk_bh(void *opaque) |
| { |
| struct XenBlkDev *blkdev = opaque; |
| blk_handle_requests(blkdev); |
| } |
| |
| static void blk_alloc(struct XenDevice *xendev) |
| { |
| struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| |
| QLIST_INIT(&blkdev->inflight); |
| QLIST_INIT(&blkdev->finished); |
| QLIST_INIT(&blkdev->freelist); |
| blkdev->bh = qemu_bh_new(blk_bh, blkdev); |
| if (xen_mode != XEN_EMULATE) { |
| batch_maps = 1; |
| } |
| } |
| |
| static int blk_init(struct XenDevice *xendev) |
| { |
| struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| int index, qflags, have_barriers, info = 0; |
| |
| /* read xenstore entries */ |
| if (blkdev->params == NULL) { |
| char *h = NULL; |
| blkdev->params = xenstore_read_be_str(&blkdev->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 (blkdev->mode == NULL) { |
| blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode"); |
| } |
| if (blkdev->type == NULL) { |
| blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type"); |
| } |
| if (blkdev->dev == NULL) { |
| blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev"); |
| } |
| if (blkdev->devtype == NULL) { |
| blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type"); |
| } |
| |
| /* 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") == 0) { |
| qflags = BDRV_O_RDWR; |
| } else { |
| qflags = 0; |
| info |= VDISK_READONLY; |
| } |
| |
| /* cdrom ? */ |
| if (blkdev->devtype && !strcmp(blkdev->devtype, "cdrom")) { |
| info |= VDISK_CDROM; |
| } |
| |
| /* init qemu block driver */ |
| index = (blkdev->xendev.dev - 202 * 256) / 16; |
| blkdev->dinfo = drive_get(IF_XEN, 0, index); |
| if (!blkdev->dinfo) { |
| /* setup via xenbus -> create new block driver instance */ |
| xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n"); |
| blkdev->bs = bdrv_new(blkdev->dev); |
| if (blkdev->bs) { |
| if (bdrv_open(blkdev->bs, blkdev->filename, qflags, |
| bdrv_find_whitelisted_format(blkdev->fileproto)) != 0) { |
| bdrv_delete(blkdev->bs); |
| blkdev->bs = NULL; |
| } |
| } |
| if (!blkdev->bs) { |
| goto out_error; |
| } |
| } else { |
| /* setup via qemu cmdline -> already setup for us */ |
| xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n"); |
| blkdev->bs = blkdev->dinfo->bdrv; |
| } |
| blkdev->file_blk = BLOCK_SIZE; |
| blkdev->file_size = bdrv_getlength(blkdev->bs); |
| if (blkdev->file_size < 0) { |
| xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n", |
| (int)blkdev->file_size, strerror(-blkdev->file_size), |
| blkdev->bs->drv ? blkdev->bs->drv->format_name : "-"); |
| blkdev->file_size = 0; |
| } |
| have_barriers = blkdev->bs->drv && blkdev->bs->drv->bdrv_flush ? 1 : 0; |
| |
| xen_be_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 info */ |
| xenstore_write_be_int(&blkdev->xendev, "feature-barrier", have_barriers); |
| xenstore_write_be_int(&blkdev->xendev, "info", info); |
| xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk); |
| xenstore_write_be_int(&blkdev->xendev, "sectors", |
| blkdev->file_size / blkdev->file_blk); |
| return 0; |
| |
| out_error: |
| qemu_free(blkdev->params); |
| blkdev->params = NULL; |
| qemu_free(blkdev->mode); |
| blkdev->mode = NULL; |
| qemu_free(blkdev->type); |
| blkdev->type = NULL; |
| qemu_free(blkdev->dev); |
| blkdev->dev = NULL; |
| qemu_free(blkdev->devtype); |
| blkdev->devtype = NULL; |
| return -1; |
| } |
| |
| static int blk_connect(struct XenDevice *xendev) |
| { |
| struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| |
| if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) { |
| return -1; |
| } |
| if (xenstore_read_fe_int(&blkdev->xendev, "event-channel", |
| &blkdev->xendev.remote_port) == -1) { |
| return -1; |
| } |
| |
| blkdev->protocol = BLKIF_PROTOCOL_NATIVE; |
| if (blkdev->xendev.protocol) { |
| if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) { |
| blkdev->protocol = BLKIF_PROTOCOL_X86_32; |
| } |
| if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) { |
| blkdev->protocol = BLKIF_PROTOCOL_X86_64; |
| } |
| } |
| |
| blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev, |
| blkdev->xendev.dom, |
| blkdev->ring_ref, |
| PROT_READ | PROT_WRITE); |
| if (!blkdev->sring) { |
| return -1; |
| } |
| blkdev->cnt_map++; |
| |
| switch (blkdev->protocol) { |
| case BLKIF_PROTOCOL_NATIVE: |
| { |
| blkif_sring_t *sring_native = blkdev->sring; |
| BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_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, XC_PAGE_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, XC_PAGE_SIZE); |
| break; |
| } |
| } |
| |
| xen_be_bind_evtchn(&blkdev->xendev); |
| |
| xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " |
| "remote port %d, local port %d\n", |
| blkdev->xendev.protocol, blkdev->ring_ref, |
| blkdev->xendev.remote_port, blkdev->xendev.local_port); |
| return 0; |
| } |
| |
| static void blk_disconnect(struct XenDevice *xendev) |
| { |
| struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| |
| if (blkdev->bs) { |
| if (!blkdev->dinfo) { |
| /* close/delete only if we created it ourself */ |
| bdrv_close(blkdev->bs); |
| bdrv_delete(blkdev->bs); |
| } |
| blkdev->bs = NULL; |
| } |
| xen_be_unbind_evtchn(&blkdev->xendev); |
| |
| if (blkdev->sring) { |
| xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1); |
| blkdev->cnt_map--; |
| blkdev->sring = NULL; |
| } |
| } |
| |
| static int blk_free(struct XenDevice *xendev) |
| { |
| struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); |
| struct ioreq *ioreq; |
| |
| while (!QLIST_EMPTY(&blkdev->freelist)) { |
| ioreq = QLIST_FIRST(&blkdev->freelist); |
| QLIST_REMOVE(ioreq, list); |
| qemu_iovec_destroy(&ioreq->v); |
| qemu_free(ioreq); |
| } |
| |
| qemu_free(blkdev->params); |
| qemu_free(blkdev->mode); |
| qemu_free(blkdev->type); |
| qemu_free(blkdev->dev); |
| qemu_free(blkdev->devtype); |
| qemu_bh_delete(blkdev->bh); |
| 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 = { |
| .size = sizeof(struct XenBlkDev), |
| .flags = DEVOPS_FLAG_NEED_GNTDEV, |
| .alloc = blk_alloc, |
| .init = blk_init, |
| .connect = blk_connect, |
| .disconnect = blk_disconnect, |
| .event = blk_event, |
| .free = blk_free, |
| }; |
