[Qemu-devel] [PULL 20/25] xen: remove the legacy 'xen_disk' backend

[Anthony PERARD <anthony.perard@citrix.com>]

From: Paul Durrant <paul.durrant@citrix.com>

This backend has now been replaced by the 'xen-qdisk' XenDevice.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---
 hw/block/Makefile.objs |    1 -
 hw/block/xen_disk.c    | 1011 ----------------------------------------
 2 files changed, 1012 deletions(-)
 delete mode 100644 hw/block/xen_disk.c

diff --git a/hw/block/Makefile.objs b/hw/block/Makefile.objs
index f34813a377..e206b8e712 100644
--- a/hw/block/Makefile.objs
+++ b/hw/block/Makefile.objs
@@ -5,7 +5,6 @@ common-obj-$(CONFIG_NAND) += nand.o
 common-obj-$(CONFIG_PFLASH_CFI01) += pflash_cfi01.o
 common-obj-$(CONFIG_PFLASH_CFI02) += pflash_cfi02.o
 common-obj-$(CONFIG_XEN) += xen-block.o
-common-obj-$(CONFIG_XEN) += xen_disk.o
 common-obj-$(CONFIG_ECC) += ecc.o
 common-obj-$(CONFIG_ONENAND) += onenand.o
 common-obj-$(CONFIG_NVME_PCI) += nvme.o
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
deleted file mode 100644
index 477dfcca9f..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-legacy-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(, ioreq) inflight;
-    QLIST_HEAD(, ioreq) finished;
-    QLIST_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,
-};
-- 
Anthony PERARD