@@ -415,6 +415,7 @@ F: hw/char/xen_console.c
F: hw/display/xenfb.c
F: hw/net/xen_nic.c
F: hw/block/xen*
+F: hw/block/dataplane/xen*
F: hw/xen/
F: hw/xenpv/
F: hw/i386/xen/
new file mode 100644
@@ -0,0 +1,1019 @@
+/*
+ * 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 XenLegacyDevice 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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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 XenLegacyDevice *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,
+};