diff options
Diffstat (limited to 'hw/block/xen_disk.c')
| -rw-r--r-- | hw/block/xen_disk.c | 1011 |
1 files changed, 0 insertions, 1011 deletions
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c deleted file mode 100644 index 36eff94f84..0000000000 --- a/hw/block/xen_disk.c +++ /dev/null @@ -1,1011 +0,0 @@ -/* - * 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, -}; |