hw: move target-independent files to subdirectories

This patch tackles all files that are compiled once, moving
them to subdirectories of hw/.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 972 insertions, 0 deletions

diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
new file mode 100644
index 0000000000..532347bf94
--- /dev/null
+++ b/hw/block/xen_disk.c
@@ -0,0 +1,972 @@
+/*
+ *  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 <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <inttypes.h>
+#include <time.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/uio.h>
+
+#include "hw/hw.h"
+#include "hw/xen/xen_backend.h"
+#include "hw/xen_blkif.h"
+#include "sysemu/blockdev.h"
+
+/* ------------------------------------------------------------- */
+
+static int batch_maps   = 0;
+
+static int max_requests = 32;
+
+/* ------------------------------------------------------------- */
+
+#define BLOCK_SIZE  512
+#define IOCB_COUNT  (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2)
+
+struct PersistentGrant {
+    void *page;
+    struct XenBlkDev *blkdev;
+};
+
+typedef struct PersistentGrant PersistentGrant;
+
+struct ioreq {
+    blkif_request_t     req;
+    int16_t             status;
+
+    /* parsed request */
+    off_t               start;
+    QEMUIOVector        v;
+    int                 presync;
+    int                 postsync;
+    uint8_t             mapped;
+
+    /* grant mapping */
+    uint32_t            domids[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+    uint32_t            refs[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+    int                 prot;
+    void                *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+    void                *pages;
+    int                 num_unmap;
+
+    /* aio status */
+    int                 aio_inflight;
+    int                 aio_errors;
+
+    struct XenBlkDev    *blkdev;
+    QLIST_ENTRY(ioreq)   list;
+    BlockAcctCookie     acct;
+};
+
+struct XenBlkDev {
+    struct XenDevice    xendev;  /* must be first */
+    char                *params;
+    char                *mode;
+    char                *type;
+    char                *dev;
+    char                *devtype;
+    const char          *fileproto;
+    const char          *filename;
+    int                 ring_ref;
+    void                *sring;
+    int64_t             file_blk;
+    int64_t             file_size;
+    int                 protocol;
+    blkif_back_rings_t  rings;
+    int                 more_work;
+    int                 cnt_map;
+
+    /* request lists */
+    QLIST_HEAD(inflight_head, ioreq) inflight;
+    QLIST_HEAD(finished_head, ioreq) finished;
+    QLIST_HEAD(freelist_head, ioreq) freelist;
+    int                 requests_total;
+    int                 requests_inflight;
+    int                 requests_finished;
+
+    /* Persistent grants extension */
+    gboolean            feature_persistent;
+    GTree               *persistent_gnts;
+    unsigned int        persistent_gnt_count;
+    unsigned int        max_grants;
+
+    /* qemu block driver */
+    DriveInfo           *dinfo;
+    BlockDriverState    *bs;
+    QEMUBH              *bh;
+};
+
+/* ------------------------------------------------------------- */
+
+static void ioreq_reset(struct ioreq *ioreq)
+{
+    memset(&ioreq->req, 0, sizeof(ioreq->req));
+    ioreq->status = 0;
+    ioreq->start = 0;
+    ioreq->presync = 0;
+    ioreq->postsync = 0;
+    ioreq->mapped = 0;
+
+    memset(ioreq->domids, 0, sizeof(ioreq->domids));
+    memset(ioreq->refs, 0, sizeof(ioreq->refs));
+    ioreq->prot = 0;
+    memset(ioreq->page, 0, sizeof(ioreq->page));
+    ioreq->pages = NULL;
+
+    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 gint int_cmp(gconstpointer a, gconstpointer b, gpointer user_data)
+{
+    uint ua = GPOINTER_TO_UINT(a);
+    uint ub = GPOINTER_TO_UINT(b);
+    return (ua > ub) - (ua < ub);
+}
+
+static void destroy_grant(gpointer pgnt)
+{
+    PersistentGrant *grant = pgnt;
+    XenGnttab gnt = grant->blkdev->xendev.gnttabdev;
+
+    if (xc_gnttab_munmap(gnt, grant->page, 1) != 0) {
+        xen_be_printf(&grant->blkdev->xendev, 0,
+                      "xc_gnttab_munmap failed: %s\n",
+                      strerror(errno));
+    }
+    grant->blkdev->persistent_gnt_count--;
+    xen_be_printf(&grant->blkdev->xendev, 3,
+                  "unmapped grant %p\n", grant->page);
+    g_free(grant);
+}
+
+static struct ioreq *ioreq_start(struct XenBlkDev *blkdev)
+{
+    struct ioreq *ioreq = NULL;
+
+    if (QLIST_EMPTY(&blkdev->freelist)) {
+        if (blkdev->requests_total >= max_requests) {
+            goto out;
+        }
+        /* allocate new struct */
+        ioreq = g_malloc0(sizeof(*ioreq));
+        ioreq->blkdev = blkdev;
+        blkdev->requests_total++;
+        qemu_iovec_init(&ioreq->v, BLKIF_MAX_SEGMENTS_PER_REQUEST);
+    } else {
+        /* get one from freelist */
+        ioreq = QLIST_FIRST(&blkdev->freelist);
+        QLIST_REMOVE(ioreq, list);
+    }
+    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;
+    uintptr_t mem;
+    size_t len;
+    int i;
+
+    xen_be_printf(&blkdev->xendev, 3,
+                  "op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n",
+                  ioreq->req.operation, ioreq->req.nr_segments,
+                  ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number);
+    switch (ioreq->req.operation) {
+    case BLKIF_OP_READ:
+        ioreq->prot = PROT_WRITE; /* to memory */
+        break;
+    case BLKIF_OP_FLUSH_DISKCACHE:
+        ioreq->presync = 1;
+        if (!ioreq->req.nr_segments) {
+            return 0;
+        }
+        /* fall through */
+    case BLKIF_OP_WRITE:
+        ioreq->prot = PROT_READ; /* from memory */
+        break;
+    default:
+        xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n",
+                      ioreq->req.operation);
+        goto err;
+    };
+
+    if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') {
+        xen_be_printf(&blkdev->xendev, 0, "error: write req for ro device\n");
+        goto err;
+    }
+
+    ioreq->start = ioreq->req.sector_number * blkdev->file_blk;
+    for (i = 0; i < ioreq->req.nr_segments; i++) {
+        if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
+            xen_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n");
+            goto err;
+        }
+        if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) {
+            xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n");
+            goto err;
+        }
+        if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) {
+            xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n");
+            goto err;
+        }
+
+        ioreq->domids[i] = blkdev->xendev.dom;
+        ioreq->refs[i]   = ioreq->req.seg[i].gref;
+
+        mem = ioreq->req.seg[i].first_sect * blkdev->file_blk;
+        len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk;
+        qemu_iovec_add(&ioreq->v, (void*)mem, len);
+    }
+    if (ioreq->start + ioreq->v.size > blkdev->file_size) {
+        xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n");
+        goto err;
+    }
+    return 0;
+
+err:
+    ioreq->status = BLKIF_RSP_ERROR;
+    return -1;
+}
+
+static void ioreq_unmap(struct ioreq *ioreq)
+{
+    XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;
+    int i;
+
+    if (ioreq->num_unmap == 0 || ioreq->mapped == 0) {
+        return;
+    }
+    if (batch_maps) {
+        if (!ioreq->pages) {
+            return;
+        }
+        if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->num_unmap) != 0) {
+            xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n",
+                          strerror(errno));
+        }
+        ioreq->blkdev->cnt_map -= ioreq->num_unmap;
+        ioreq->pages = NULL;
+    } else {
+        for (i = 0; i < ioreq->num_unmap; i++) {
+            if (!ioreq->page[i]) {
+                continue;
+            }
+            if (xc_gnttab_munmap(gnt, ioreq->page[i], 1) != 0) {
+                xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n",
+                              strerror(errno));
+            }
+            ioreq->blkdev->cnt_map--;
+            ioreq->page[i] = NULL;
+        }
+    }
+    ioreq->mapped = 0;
+}
+
+static int ioreq_map(struct ioreq *ioreq)
+{
+    XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;
+    uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+    uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+    void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+    int i, j, new_maps = 0;
+    PersistentGrant *grant;
+    /* domids and refs variables will contain the information necessary
+     * to map the grants that are needed to fulfill this request.
+     *
+     * After mapping the needed grants, the page array will contain the
+     * memory address of each granted page in the order specified in ioreq
+     * (disregarding if it's a persistent grant or not).
+     */
+
+    if (ioreq->v.niov == 0 || ioreq->mapped == 1) {
+        return 0;
+    }
+    if (ioreq->blkdev->feature_persistent) {
+        for (i = 0; i < ioreq->v.niov; i++) {
+            grant = g_tree_lookup(ioreq->blkdev->persistent_gnts,
+                                    GUINT_TO_POINTER(ioreq->refs[i]));
+
+            if (grant != NULL) {
+                page[i] = grant->page;
+                xen_be_printf(&ioreq->blkdev->xendev, 3,
+                              "using persistent-grant %" PRIu32 "\n",
+                              ioreq->refs[i]);
+            } else {
+                    /* Add the grant to the list of grants that
+                     * should be mapped
+                     */
+                    domids[new_maps] = ioreq->domids[i];
+                    refs[new_maps] = ioreq->refs[i];
+                    page[i] = NULL;
+                    new_maps++;
+            }
+        }
+        /* Set the protection to RW, since grants may be reused later
+         * with a different protection than the one needed for this request
+         */
+        ioreq->prot = PROT_WRITE | PROT_READ;
+    } else {
+        /* All grants in the request should be mapped */
+        memcpy(refs, ioreq->refs, sizeof(refs));
+        memcpy(domids, ioreq->domids, sizeof(domids));
+        memset(page, 0, sizeof(page));
+        new_maps = ioreq->v.niov;
+    }
+
+    if (batch_maps && new_maps) {
+        ioreq->pages = xc_gnttab_map_grant_refs
+            (gnt, new_maps, domids, refs, ioreq->prot);
+        if (ioreq->pages == NULL) {
+            xen_be_printf(&ioreq->blkdev->xendev, 0,
+                          "can't map %d grant refs (%s, %d maps)\n",
+                          new_maps, strerror(errno), ioreq->blkdev->cnt_map);
+            return -1;
+        }
+        for (i = 0, j = 0; i < ioreq->v.niov; i++) {
+            if (page[i] == NULL) {
+                page[i] = ioreq->pages + (j++) * XC_PAGE_SIZE;
+            }
+        }
+        ioreq->blkdev->cnt_map += new_maps;
+    } else if (new_maps)  {
+        for (i = 0; i < new_maps; i++) {
+            ioreq->page[i] = xc_gnttab_map_grant_ref
+                (gnt, domids[i], refs[i], ioreq->prot);
+            if (ioreq->page[i] == NULL) {
+                xen_be_printf(&ioreq->blkdev->xendev, 0,
+                              "can't map grant ref %d (%s, %d maps)\n",
+                              refs[i], strerror(errno), ioreq->blkdev->cnt_map);
+                ioreq_unmap(ioreq);
+                return -1;
+            }
+            ioreq->blkdev->cnt_map++;
+        }
+        for (i = 0, j = 0; i < ioreq->v.niov; i++) {
+            if (page[i] == NULL) {
+                page[i] = ioreq->page[j++];
+            }
+        }
+    }
+    if (ioreq->blkdev->feature_persistent) {
+        while ((ioreq->blkdev->persistent_gnt_count < ioreq->blkdev->max_grants)
+              && new_maps) {
+            /* Go through the list of newly mapped grants and add as many
+             * as possible to the list of persistently mapped grants.
+             *
+             * Since we start at the end of ioreq->page(s), we only need
+             * to decrease new_maps to prevent this granted pages from
+             * being unmapped in ioreq_unmap.
+             */
+            grant = g_malloc0(sizeof(*grant));
+            new_maps--;
+            if (batch_maps) {
+                grant->page = ioreq->pages + (new_maps) * XC_PAGE_SIZE;
+            } else {
+                grant->page = ioreq->page[new_maps];
+            }
+            grant->blkdev = ioreq->blkdev;
+            xen_be_printf(&ioreq->blkdev->xendev, 3,
+                          "adding grant %" PRIu32 " page: %p\n",
+                          refs[new_maps], grant->page);
+            g_tree_insert(ioreq->blkdev->persistent_gnts,
+                          GUINT_TO_POINTER(refs[new_maps]),
+                          grant);
+            ioreq->blkdev->persistent_gnt_count++;
+        }
+    }
+    for (i = 0; i < ioreq->v.niov; i++) {
+        ioreq->v.iov[i].iov_base += (uintptr_t)page[i];
+    }
+    ioreq->mapped = 1;
+    ioreq->num_unmap = new_maps;
+    return 0;
+}
+
+static int ioreq_runio_qemu_aio(struct ioreq *ioreq);
+
+static void qemu_aio_complete(void *opaque, int ret)
+{
+    struct ioreq *ioreq = opaque;
+
+    if (ret != 0) {
+        xen_be_printf(&ioreq->blkdev->xendev, 0, "%s I/O error\n",
+                      ioreq->req.operation == BLKIF_OP_READ ? "read" : "write");
+        ioreq->aio_errors++;
+    }
+
+    ioreq->aio_inflight--;
+    if (ioreq->presync) {
+        ioreq->presync = 0;
+        ioreq_runio_qemu_aio(ioreq);
+        return;
+    }
+    if (ioreq->aio_inflight > 0) {
+        return;
+    }
+    if (ioreq->postsync) {
+        ioreq->postsync = 0;
+        ioreq->aio_inflight++;
+        bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq);
+        return;
+    }
+
+    ioreq->status = ioreq->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY;
+    ioreq_unmap(ioreq);
+    ioreq_finish(ioreq);
+    bdrv_acct_done(ioreq->blkdev->bs, &ioreq->acct);
+    qemu_bh_schedule(ioreq->blkdev->bh);
+}
+
+static int ioreq_runio_qemu_aio(struct ioreq *ioreq)
+{
+    struct XenBlkDev *blkdev = ioreq->blkdev;
+
+    if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) {
+        goto err_no_map;
+    }
+
+    ioreq->aio_inflight++;
+    if (ioreq->presync) {
+        bdrv_aio_flush(ioreq->blkdev->bs, qemu_aio_complete, ioreq);
+        return 0;
+    }
+
+    switch (ioreq->req.operation) {
+    case BLKIF_OP_READ:
+        bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_READ);
+        ioreq->aio_inflight++;
+        bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE,
+                       &ioreq->v, ioreq->v.size / BLOCK_SIZE,
+                       qemu_aio_complete, ioreq);
+        break;
+    case BLKIF_OP_WRITE:
+    case BLKIF_OP_FLUSH_DISKCACHE:
+        if (!ioreq->req.nr_segments) {
+            break;
+        }
+
+        bdrv_acct_start(blkdev->bs, &ioreq->acct, ioreq->v.size, BDRV_ACCT_WRITE);
+        ioreq->aio_inflight++;
+        bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE,
+                        &ioreq->v, ioreq->v.size / BLOCK_SIZE,
+                        qemu_aio_complete, ioreq);
+        break;
+    default:
+        /* unknown operation (shouldn't happen -- parse catches this) */
+        goto err;
+    }
+
+    qemu_aio_complete(ioreq, 0);
+
+    return 0;
+
+err:
+    ioreq_unmap(ioreq);
+err_no_map:
+    ioreq_finish(ioreq);
+    ioreq->status = BLKIF_RSP_ERROR;
+    return -1;
+}
+
+static int blk_send_response_one(struct ioreq *ioreq)
+{
+    struct XenBlkDev  *blkdev = ioreq->blkdev;
+    int               send_notify   = 0;
+    int               have_requests = 0;
+    blkif_response_t  resp;
+    void              *dst;
+
+    resp.id        = ioreq->req.id;
+    resp.operation = ioreq->req.operation;
+    resp.status    = ioreq->status;
+
+    /* Place on the response ring for the relevant domain. */
+    switch (blkdev->protocol) {
+    case BLKIF_PROTOCOL_NATIVE:
+        dst = RING_GET_RESPONSE(&blkdev->rings.native, blkdev->rings.native.rsp_prod_pvt);
+        break;
+    case BLKIF_PROTOCOL_X86_32:
+        dst = RING_GET_RESPONSE(&blkdev->rings.x86_32_part,
+                                blkdev->rings.x86_32_part.rsp_prod_pvt);
+        break;
+    case BLKIF_PROTOCOL_X86_64:
+        dst = RING_GET_RESPONSE(&blkdev->rings.x86_64_part,
+                                blkdev->rings.x86_64_part.rsp_prod_pvt);
+        break;
+    default:
+        dst = NULL;
+    }
+    memcpy(dst, &resp, sizeof(resp));
+    blkdev->rings.common.rsp_prod_pvt++;
+
+    RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blkdev->rings.common, send_notify);
+    if (blkdev->rings.common.rsp_prod_pvt == blkdev->rings.common.req_cons) {
+        /*
+         * Tail check for pending requests. Allows frontend to avoid
+         * notifications if requests are already in flight (lower
+         * overheads and promotes batching).
+         */
+        RING_FINAL_CHECK_FOR_REQUESTS(&blkdev->rings.common, have_requests);
+    } else if (RING_HAS_UNCONSUMED_REQUESTS(&blkdev->rings.common)) {
+        have_requests = 1;
+    }
+
+    if (have_requests) {
+        blkdev->more_work++;
+    }
+    return send_notify;
+}
+
+/* walk finished list, send outstanding responses, free requests */
+static void blk_send_response_all(struct XenBlkDev *blkdev)
+{
+    struct ioreq *ioreq;
+    int send_notify = 0;
+
+    while (!QLIST_EMPTY(&blkdev->finished)) {
+        ioreq = QLIST_FIRST(&blkdev->finished);
+        send_notify += blk_send_response_one(ioreq);
+        ioreq_release(ioreq, true);
+    }
+    if (send_notify) {
+        xen_be_send_notify(&blkdev->xendev);
+    }
+}
+
+static int blk_get_request(struct XenBlkDev *blkdev, struct ioreq *ioreq, RING_IDX rc)
+{
+    switch (blkdev->protocol) {
+    case BLKIF_PROTOCOL_NATIVE:
+        memcpy(&ioreq->req, RING_GET_REQUEST(&blkdev->rings.native, rc),
+               sizeof(ioreq->req));
+        break;
+    case BLKIF_PROTOCOL_X86_32:
+        blkif_get_x86_32_req(&ioreq->req,
+                             RING_GET_REQUEST(&blkdev->rings.x86_32_part, rc));
+        break;
+    case BLKIF_PROTOCOL_X86_64:
+        blkif_get_x86_64_req(&ioreq->req,
+                             RING_GET_REQUEST(&blkdev->rings.x86_64_part, rc));
+        break;
+    }
+    return 0;
+}
+
+static void blk_handle_requests(struct XenBlkDev *blkdev)
+{
+    RING_IDX rc, rp;
+    struct ioreq *ioreq;
+
+    blkdev->more_work = 0;
+
+    rc = blkdev->rings.common.req_cons;
+    rp = blkdev->rings.common.sring->req_prod;
+    xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
+
+    blk_send_response_all(blkdev);
+    while (rc != rp) {
+        /* pull request from ring */
+        if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
+            break;
+        }
+        ioreq = ioreq_start(blkdev);
+        if (ioreq == NULL) {
+            blkdev->more_work++;
+            break;
+        }
+        blk_get_request(blkdev, ioreq, rc);
+        blkdev->rings.common.req_cons = ++rc;
+
+        /* parse them */
+        if (ioreq_parse(ioreq) != 0) {
+            if (blk_send_response_one(ioreq)) {
+                xen_be_send_notify(&blkdev->xendev);
+            }
+            ioreq_release(ioreq, false);
+            continue;
+        }
+
+        ioreq_runio_qemu_aio(ioreq);
+    }
+
+    if (blkdev->more_work && blkdev->requests_inflight < max_requests) {
+        qemu_bh_schedule(blkdev->bh);
+    }
+}
+
+/* ------------------------------------------------------------- */
+
+static void blk_bh(void *opaque)
+{
+    struct XenBlkDev *blkdev = opaque;
+    blk_handle_requests(blkdev);
+}
+
+/*
+ * We need to account for the grant allocations requiring contiguous
+ * chunks; the worst case number would be
+ *     max_req * max_seg + (max_req - 1) * (max_seg - 1) + 1,
+ * but in order to keep things simple just use
+ *     2 * max_req * max_seg.
+ */
+#define MAX_GRANTS(max_req, max_seg) (2 * (max_req) * (max_seg))
+
+static void blk_alloc(struct XenDevice *xendev)
+{
+    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
+
+    QLIST_INIT(&blkdev->inflight);
+    QLIST_INIT(&blkdev->finished);
+    QLIST_INIT(&blkdev->freelist);
+    blkdev->bh = qemu_bh_new(blk_bh, blkdev);
+    if (xen_mode != XEN_EMULATE) {
+        batch_maps = 1;
+    }
+    if (xc_gnttab_set_max_grants(xendev->gnttabdev,
+            MAX_GRANTS(max_requests, BLKIF_MAX_SEGMENTS_PER_REQUEST)) < 0) {
+        xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n",
+                      strerror(errno));
+    }
+}
+
+static int blk_init(struct XenDevice *xendev)
+{
+    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
+    int info = 0;
+
+    /* read xenstore entries */
+    if (blkdev->params == NULL) {
+        char *h = NULL;
+        blkdev->params = xenstore_read_be_str(&blkdev->xendev, "params");
+        if (blkdev->params != NULL) {
+            h = strchr(blkdev->params, ':');
+        }
+        if (h != NULL) {
+            blkdev->fileproto = blkdev->params;
+            blkdev->filename  = h+1;
+            *h = 0;
+        } else {
+            blkdev->fileproto = "<unset>";
+            blkdev->filename  = blkdev->params;
+        }
+    }
+    if (!strcmp("aio", blkdev->fileproto)) {
+        blkdev->fileproto = "raw";
+    }
+    if (blkdev->mode == NULL) {
+        blkdev->mode = xenstore_read_be_str(&blkdev->xendev, "mode");
+    }
+    if (blkdev->type == NULL) {
+        blkdev->type = xenstore_read_be_str(&blkdev->xendev, "type");
+    }
+    if (blkdev->dev == NULL) {
+        blkdev->dev = xenstore_read_be_str(&blkdev->xendev, "dev");
+    }
+    if (blkdev->devtype == NULL) {
+        blkdev->devtype = xenstore_read_be_str(&blkdev->xendev, "device-type");
+    }
+
+    /* do we have all we need? */
+    if (blkdev->params == NULL ||
+        blkdev->mode == NULL   ||
+        blkdev->type == NULL   ||
+        blkdev->dev == NULL) {
+        goto out_error;
+    }
+
+    /* read-only ? */
+    if (strcmp(blkdev->mode, "w")) {
+        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(&blkdev->xendev, "feature-flush-cache", 1);
+    xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1);
+    xenstore_write_be_int(&blkdev->xendev, "info", info);
+    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;
+    return -1;
+}
+
+static int blk_connect(struct XenDevice *xendev)
+{
+    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
+    int pers, index, qflags;
+
+    /* read-only ? */
+    qflags = BDRV_O_CACHE_WB | BDRV_O_NATIVE_AIO;
+    if (strcmp(blkdev->mode, "w") == 0) {
+        qflags |= BDRV_O_RDWR;
+    }
+
+    /* init qemu block driver */
+    index = (blkdev->xendev.dev - 202 * 256) / 16;
+    blkdev->dinfo = drive_get(IF_XEN, 0, index);
+    if (!blkdev->dinfo) {
+        /* setup via xenbus -> create new block driver instance */
+        xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n");
+        blkdev->bs = bdrv_new(blkdev->dev);
+        if (blkdev->bs) {
+            if (bdrv_open(blkdev->bs, blkdev->filename, NULL, qflags,
+                        bdrv_find_whitelisted_format(blkdev->fileproto)) != 0) {
+                bdrv_delete(blkdev->bs);
+                blkdev->bs = NULL;
+            }
+        }
+        if (!blkdev->bs) {
+            return -1;
+        }
+    } else {
+        /* setup via qemu cmdline -> already setup for us */
+        xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n");
+        blkdev->bs = blkdev->dinfo->bdrv;
+    }
+    bdrv_attach_dev_nofail(blkdev->bs, blkdev);
+    blkdev->file_size = bdrv_getlength(blkdev->bs);
+    if (blkdev->file_size < 0) {
+        xen_be_printf(&blkdev->xendev, 1, "bdrv_getlength: %d (%s) | drv %s\n",
+                      (int)blkdev->file_size, strerror(-blkdev->file_size),
+                      bdrv_get_format_name(blkdev->bs) ?: "-");
+        blkdev->file_size = 0;
+    }
+
+    xen_be_printf(xendev, 1, "type \"%s\", fileproto \"%s\", filename \"%s\","
+                  " size %" PRId64 " (%" PRId64 " MB)\n",
+                  blkdev->type, blkdev->fileproto, blkdev->filename,
+                  blkdev->file_size, blkdev->file_size >> 20);
+
+    /* Fill in number of sector size and number of sectors */
+    xenstore_write_be_int(&blkdev->xendev, "sector-size", blkdev->file_blk);
+    xenstore_write_be_int64(&blkdev->xendev, "sectors",
+                            blkdev->file_size / blkdev->file_blk);
+
+    if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) {
+        return -1;
+    }
+    if (xenstore_read_fe_int(&blkdev->xendev, "event-channel",
+                             &blkdev->xendev.remote_port) == -1) {
+        return -1;
+    }
+    if (xenstore_read_fe_int(&blkdev->xendev, "feature-persistent", &pers)) {
+        blkdev->feature_persistent = FALSE;
+    } else {
+        blkdev->feature_persistent = !!pers;
+    }
+
+    blkdev->protocol = BLKIF_PROTOCOL_NATIVE;
+    if (blkdev->xendev.protocol) {
+        if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_32) == 0) {
+            blkdev->protocol = BLKIF_PROTOCOL_X86_32;
+        }
+        if (strcmp(blkdev->xendev.protocol, XEN_IO_PROTO_ABI_X86_64) == 0) {
+            blkdev->protocol = BLKIF_PROTOCOL_X86_64;
+        }
+    }
+
+    blkdev->sring = xc_gnttab_map_grant_ref(blkdev->xendev.gnttabdev,
+                                            blkdev->xendev.dom,
+                                            blkdev->ring_ref,
+                                            PROT_READ | PROT_WRITE);
+    if (!blkdev->sring) {
+        return -1;
+    }
+    blkdev->cnt_map++;
+
+    switch (blkdev->protocol) {
+    case BLKIF_PROTOCOL_NATIVE:
+    {
+        blkif_sring_t *sring_native = blkdev->sring;
+        BACK_RING_INIT(&blkdev->rings.native, sring_native, XC_PAGE_SIZE);
+        break;
+    }
+    case BLKIF_PROTOCOL_X86_32:
+    {
+        blkif_x86_32_sring_t *sring_x86_32 = blkdev->sring;
+
+        BACK_RING_INIT(&blkdev->rings.x86_32_part, sring_x86_32, XC_PAGE_SIZE);
+        break;
+    }
+    case BLKIF_PROTOCOL_X86_64:
+    {
+        blkif_x86_64_sring_t *sring_x86_64 = blkdev->sring;
+
+        BACK_RING_INIT(&blkdev->rings.x86_64_part, sring_x86_64, XC_PAGE_SIZE);
+        break;
+    }
+    }
+
+    if (blkdev->feature_persistent) {
+        /* Init persistent grants */
+        blkdev->max_grants = max_requests * BLKIF_MAX_SEGMENTS_PER_REQUEST;
+        blkdev->persistent_gnts = g_tree_new_full((GCompareDataFunc)int_cmp,
+                                             NULL, NULL,
+                                             (GDestroyNotify)destroy_grant);
+        blkdev->persistent_gnt_count = 0;
+    }
+
+    xen_be_bind_evtchn(&blkdev->xendev);
+
+    xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, "
+                  "remote port %d, local port %d\n",
+                  blkdev->xendev.protocol, blkdev->ring_ref,
+                  blkdev->xendev.remote_port, blkdev->xendev.local_port);
+    return 0;
+}
+
+static void blk_disconnect(struct XenDevice *xendev)
+{
+    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
+
+    if (blkdev->bs) {
+        if (!blkdev->dinfo) {
+            /* close/delete only if we created it ourself */
+            bdrv_close(blkdev->bs);
+            bdrv_detach_dev(blkdev->bs, blkdev);
+            bdrv_delete(blkdev->bs);
+        }
+        blkdev->bs = NULL;
+    }
+    xen_be_unbind_evtchn(&blkdev->xendev);
+
+    if (blkdev->sring) {
+        xc_gnttab_munmap(blkdev->xendev.gnttabdev, blkdev->sring, 1);
+        blkdev->cnt_map--;
+        blkdev->sring = NULL;
+    }
+}
+
+static int blk_free(struct XenDevice *xendev)
+{
+    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
+    struct ioreq *ioreq;
+
+    if (blkdev->bs || blkdev->sring) {
+        blk_disconnect(xendev);
+    }
+
+    /* Free persistent grants */
+    if (blkdev->feature_persistent) {
+        g_tree_destroy(blkdev->persistent_gnts);
+    }
+
+    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);
+    return 0;
+}
+
+static void blk_event(struct XenDevice *xendev)
+{
+    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
+
+    qemu_bh_schedule(blkdev->bh);
+}
+
+struct XenDevOps xen_blkdev_ops = {
+    .size       = sizeof(struct XenBlkDev),
+    .flags      = DEVOPS_FLAG_NEED_GNTDEV,
+    .alloc      = blk_alloc,
+    .init       = blk_init,
+    .initialise    = blk_connect,
+    .disconnect = blk_disconnect,
+    .event      = blk_event,
+    .free       = blk_free,
+};