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