virtio: add feature checking helpers

[qemu.git] / hw / scsi / virtio-scsi.c

diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index ec9a5362f7935b73322fb8195c4cd4c58aaafdf5..c5d910995f21745bae2d1f76cb73ec3b6fcc5c61 100644 (file)
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -13,33 +13,16 @@
  *
  */
 
  *
  */
 

+#include "standard-headers/linux/virtio_ids.h"

 #include "hw/virtio/virtio-scsi.h"
 #include "qemu/error-report.h"
 #include "qemu/iov.h"
 #include "hw/virtio/virtio-scsi.h"
 #include "qemu/error-report.h"
 #include "qemu/iov.h"

+#include "sysemu/block-backend.h"

 #include <hw/scsi/scsi.h>
 #include <block/scsi.h>
 #include <hw/virtio/virtio-bus.h>
 #include <hw/scsi/scsi.h>
 #include <block/scsi.h>
 #include <hw/virtio/virtio-bus.h>

-
-typedef struct VirtIOSCSIReq {
-    VirtIOSCSI *dev;
-    VirtQueue *vq;
-    VirtQueueElement elem;
-    QEMUSGList qsgl;
-    SCSIRequest *sreq;
-    union {
-        char                  *buf;
-        VirtIOSCSICmdReq      *cmd;
-        VirtIOSCSICtrlTMFReq  *tmf;
-        VirtIOSCSICtrlANReq   *an;
-    } req;
-    union {
-        char                  *buf;
-        VirtIOSCSICmdResp     *cmd;
-        VirtIOSCSICtrlTMFResp *tmf;
-        VirtIOSCSICtrlANResp  *an;
-        VirtIOSCSIEvent       *event;
-    } resp;
-} VirtIOSCSIReq;
+#include "hw/virtio/virtio-access.h"
+#include "migration/migration.h"

 
 static inline int virtio_scsi_get_lun(uint8_t *lun)
 {
 
 static inline int virtio_scsi_get_lun(uint8_t *lun)
 {


@@ -57,22 +40,29 @@ static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
 }
 
     return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
 }
 

-static VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)
+VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)

 {
     VirtIOSCSIReq *req;
 {
     VirtIOSCSIReq *req;

-    req = g_malloc(sizeof(*req));
+    VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
+    const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)
+                             + sizeof(VirtQueueElement);

 
 

+    req = g_slice_alloc(sizeof(*req) + vs->cdb_size);

     req->vq = vq;
     req->dev = s;
     req->vq = vq;
     req->dev = s;

-    req->sreq = NULL;

     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);
     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);

+    qemu_iovec_init(&req->resp_iov, 1);
+    memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);

     return req;
 }
 
     return req;
 }
 

-static void virtio_scsi_free_req(VirtIOSCSIReq *req)
+void virtio_scsi_free_req(VirtIOSCSIReq *req)

 {
 {

+    VirtIOSCSICommon *vs = (VirtIOSCSICommon *)req->dev;
+
+    qemu_iovec_destroy(&req->resp_iov);

     qemu_sglist_destroy(&req->qsgl);
     qemu_sglist_destroy(&req->qsgl);

-    g_free(req);
+    g_slice_free1(sizeof(*req) + vs->cdb_size, req);

 }
 
 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
 }
 
 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)


@@ -80,13 +70,21 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
     VirtIOSCSI *s = req->dev;
     VirtQueue *vq = req->vq;
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
     VirtIOSCSI *s = req->dev;
     VirtQueue *vq = req->vq;
     VirtIODevice *vdev = VIRTIO_DEVICE(s);

-    virtqueue_push(vq, &req->elem, req->qsgl.size + req->elem.in_sg[0].iov_len);
+
+    qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
+    if (req->vring) {
+        assert(req->vq == NULL);
+        virtio_scsi_vring_push_notify(req);
+    } else {
+        virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
+        virtio_notify(vdev, vq);
+    }
+

     if (req->sreq) {
         req->sreq->hba_private = NULL;
         scsi_req_unref(req->sreq);
     }
     virtio_scsi_free_req(req);
     if (req->sreq) {
         req->sreq->hba_private = NULL;
         scsi_req_unref(req->sreq);
     }
     virtio_scsi_free_req(req);

-    virtio_notify(vdev, vq);

 }
 
 static void virtio_scsi_bad_req(void)
 }
 
 static void virtio_scsi_bad_req(void)


@@ -95,43 +93,78 @@ static void virtio_scsi_bad_req(void)
     exit(1);
 }
 
     exit(1);
 }
 

-static void qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *sg,
-                                   hwaddr *addr, int num)
+static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
+                              hwaddr *addr, int num, size_t skip)

 {
     QEMUSGList *qsgl = &req->qsgl;
 {
     QEMUSGList *qsgl = &req->qsgl;

-
-    while (num--) {
-        qemu_sglist_add(qsgl, *(addr++), (sg++)->iov_len);
+    size_t copied = 0;
+
+    while (num) {
+        if (skip >= iov->iov_len) {
+            skip -= iov->iov_len;
+        } else {
+            qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
+            copied += iov->iov_len - skip;
+            skip = 0;
+        }
+        iov++;
+        addr++;
+        num--;

     }
     }

+
+    assert(skip == 0);
+    return copied;

 }
 
 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
                                  unsigned req_size, unsigned resp_size)
 {
 }
 
 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
                                  unsigned req_size, unsigned resp_size)
 {

-    if (req->elem.in_num == 0) {
+    VirtIODevice *vdev = (VirtIODevice *) req->dev;
+    size_t in_size, out_size;
+
+    if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
+                   &req->req, req_size) < req_size) {

         return -EINVAL;
     }
 
         return -EINVAL;
     }
 

-    if (req->elem.out_sg[0].iov_len < req_size) {
+    if (qemu_iovec_concat_iov(&req->resp_iov,
+                              req->elem.in_sg, req->elem.in_num, 0,
+                              resp_size) < resp_size) {

         return -EINVAL;
     }
         return -EINVAL;
     }

-    if (req->elem.out_num) {
-        req->req.buf = req->elem.out_sg[0].iov_base;
+
+    req->resp_size = resp_size;
+
+    /* Old BIOSes left some padding by mistake after the req_size/resp_size.
+     * As a workaround, always consider the first buffer as the virtio-scsi
+     * request/response, making the payload start at the second element
+     * of the iovec.
+     *
+     * The actual length of the response header, stored in req->resp_size,
+     * does not change.
+     *
+     * TODO: always disable this workaround for virtio 1.0 devices.
+     */
+    if (!virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
+        req_size = req->elem.out_sg[0].iov_len;
+        resp_size = req->elem.in_sg[0].iov_len;

     }
 
     }
 

-    if (req->elem.in_sg[0].iov_len < resp_size) {
-        return -EINVAL;
+    out_size = qemu_sgl_concat(req, req->elem.out_sg,
+                               &req->elem.out_addr[0], req->elem.out_num,
+                               req_size);
+    in_size = qemu_sgl_concat(req, req->elem.in_sg,
+                              &req->elem.in_addr[0], req->elem.in_num,
+                              resp_size);
+
+    if (out_size && in_size) {
+        return -ENOTSUP;

     }
     }

-    req->resp.buf = req->elem.in_sg[0].iov_base;

 
 

-    if (req->elem.out_num > 1) {
-        qemu_sgl_concat(req, &req->elem.out_sg[1],
-                        &req->elem.out_addr[1],
-                        req->elem.out_num - 1);
-    } else {
-        qemu_sgl_concat(req, &req->elem.in_sg[1],
-                        &req->elem.in_addr[1],
-                        req->elem.in_num - 1);
+    if (out_size) {
+        req->mode = SCSI_XFER_TO_DEV;
+    } else if (in_size) {
+        req->mode = SCSI_XFER_FROM_DEV;

     }
 
     return 0;
     }
 
     return 0;


@@ -189,37 +222,60 @@ static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
     scsi_req_ref(sreq);
     req->sreq = sreq;
     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
     scsi_req_ref(sreq);
     req->sreq = sreq;
     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {

-        int req_mode =
-            (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
-
-        assert(req->sreq->cmd.mode == req_mode);
+        assert(req->sreq->cmd.mode == req->mode);

     }
     return req;
 }
 
     }
     return req;
 }
 

-static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
+typedef struct {
+    Notifier        notifier;
+    VirtIOSCSIReq  *tmf_req;
+} VirtIOSCSICancelNotifier;
+
+static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)

 {
 {

-    SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf->lun);
+    VirtIOSCSICancelNotifier *n = container_of(notifier,
+                                               VirtIOSCSICancelNotifier,
+                                               notifier);
+
+    if (--n->tmf_req->remaining == 0) {
+        virtio_scsi_complete_req(n->tmf_req);
+    }
+    g_slice_free(VirtIOSCSICancelNotifier, n);
+}
+
+/* Return 0 if the request is ready to be completed and return to guest;
+ * -EINPROGRESS if the request is submitted and will be completed later, in the
+ *  case of async cancellation. */
+static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
+{
+    SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);

     SCSIRequest *r, *next;
     BusChild *kid;
     int target;
     SCSIRequest *r, *next;
     BusChild *kid;
     int target;

+    int ret = 0;

 
 

+    if (s->dataplane_started && blk_get_aio_context(d->conf.blk) != s->ctx) {
+        aio_context_acquire(s->ctx);
+        blk_set_aio_context(d->conf.blk, s->ctx);
+        aio_context_release(s->ctx);
+    }

     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */

-    req->resp.tmf->response = VIRTIO_SCSI_S_OK;
+    req->resp.tmf.response = VIRTIO_SCSI_S_OK;

 
 

-    tswap32s(&req->req.tmf->subtype);
-    switch (req->req.tmf->subtype) {
+    virtio_tswap32s(VIRTIO_DEVICE(s), &req->req.tmf.subtype);
+    switch (req->req.tmf.subtype) {

     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
         if (!d) {
             goto fail;
         }
     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
         if (!d) {
             goto fail;
         }

-        if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
+        if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {

             goto incorrect_lun;
         }
         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
             VirtIOSCSIReq *cmd_req = r->hba_private;
             goto incorrect_lun;
         }
         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
             VirtIOSCSIReq *cmd_req = r->hba_private;

-            if (cmd_req && cmd_req->req.cmd->tag == req->req.tmf->tag) {
+            if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {

                 break;
             }
         }
                 break;
             }
         }


@@ -229,13 +285,20 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
              * check for it in the loop above.
              */
             assert(r->hba_private);
              * check for it in the loop above.
              */
             assert(r->hba_private);

-            if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
+            if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {

                 /* "If the specified command is present in the task set, then
                  * return a service response set to FUNCTION SUCCEEDED".
                  */
                 /* "If the specified command is present in the task set, then
                  * return a service response set to FUNCTION SUCCEEDED".
                  */

-                req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
+                req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;

             } else {
             } else {

-                scsi_req_cancel(r);
+                VirtIOSCSICancelNotifier *notifier;
+
+                req->remaining = 1;
+                notifier = g_slice_new(VirtIOSCSICancelNotifier);
+                notifier->tmf_req = req;
+                notifier->notifier.notify = virtio_scsi_cancel_notify;
+                scsi_req_cancel_async(r, &notifier->notifier);
+                ret = -EINPROGRESS;

             }
         }
         break;
             }
         }
         break;


@@ -244,7 +307,7 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
         if (!d) {
             goto fail;
         }
         if (!d) {
             goto fail;
         }

-        if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
+        if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {

             goto incorrect_lun;
         }
         s->resetting++;
             goto incorrect_lun;
         }
         s->resetting++;


@@ -258,26 +321,42 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
         if (!d) {
             goto fail;
         }
         if (!d) {
             goto fail;
         }

-        if (d->lun != virtio_scsi_get_lun(req->req.tmf->lun)) {
+        if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {

             goto incorrect_lun;
         }
             goto incorrect_lun;
         }

+
+        /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
+         * This way, if the bus starts calling back to the notifiers
+         * even before we finish the loop, virtio_scsi_cancel_notify
+         * will not complete the TMF too early.
+         */
+        req->remaining = 1;

         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
             if (r->hba_private) {
         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
             if (r->hba_private) {

-                if (req->req.tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
+                if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {

                     /* "If there is any command present in the task set, then
                      * return a service response set to FUNCTION SUCCEEDED".
                      */
                     /* "If there is any command present in the task set, then
                      * return a service response set to FUNCTION SUCCEEDED".
                      */

-                    req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
+                    req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;

                     break;
                 } else {
                     break;
                 } else {

-                    scsi_req_cancel(r);
+                    VirtIOSCSICancelNotifier *notifier;
+
+                    req->remaining++;
+                    notifier = g_slice_new(VirtIOSCSICancelNotifier);
+                    notifier->notifier.notify = virtio_scsi_cancel_notify;
+                    notifier->tmf_req = req;
+                    scsi_req_cancel_async(r, &notifier->notifier);

                 }
             }
         }
                 }
             }
         }

+        if (--req->remaining > 0) {
+            ret = -EINPROGRESS;
+        }

         break;
 
     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
         break;
 
     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:

-        target = req->req.tmf->lun[1];
+        target = req->req.tmf.lun[1];

         s->resetting++;
         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
              d = DO_UPCAST(SCSIDevice, qdev, kid->child);
         s->resetting++;
         QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
              d = DO_UPCAST(SCSIDevice, qdev, kid->child);


@@ -290,80 +369,125 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
 
     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
     default:
 
     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
     default:

-        req->resp.tmf->response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
+        req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;

         break;
     }
 
         break;
     }
 

-    return;
+    return ret;

 
 incorrect_lun:
 
 incorrect_lun:

-    req->resp.tmf->response = VIRTIO_SCSI_S_INCORRECT_LUN;
-    return;
+    req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
+    return ret;

 
 fail:
 
 fail:

-    req->resp.tmf->response = VIRTIO_SCSI_S_BAD_TARGET;
+    req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
+    return ret;

 }
 
 }
 

-static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)

 {
 {

-    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
-    VirtIOSCSIReq *req;
+    VirtIODevice *vdev = (VirtIODevice *)s;
+    uint32_t type;
+    int r = 0;

 
 

-    while ((req = virtio_scsi_pop_req(s, vq))) {
-        int type;
+    if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
+                &type, sizeof(type)) < sizeof(type)) {
+        virtio_scsi_bad_req();
+        return;
+    }

 
 

-        if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
-                       &type, sizeof(type)) < sizeof(type)) {
+    virtio_tswap32s(vdev, &type);
+    if (type == VIRTIO_SCSI_T_TMF) {
+        if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
+                    sizeof(VirtIOSCSICtrlTMFResp)) < 0) {

             virtio_scsi_bad_req();
             virtio_scsi_bad_req();

-            continue;
+        } else {
+            r = virtio_scsi_do_tmf(s, req);

         }
 
         }
 

-        tswap32s(&req->req.tmf->type);
-        if (req->req.tmf->type == VIRTIO_SCSI_T_TMF) {
-            if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
-                                      sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
-                virtio_scsi_bad_req();
-            } else {
-                virtio_scsi_do_tmf(s, req);
-            }
-
-        } else if (req->req.tmf->type == VIRTIO_SCSI_T_AN_QUERY ||
-                   req->req.tmf->type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
-            if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
-                                      sizeof(VirtIOSCSICtrlANResp)) < 0) {
-                virtio_scsi_bad_req();
-            } else {
-                req->resp.an->event_actual = 0;
-                req->resp.an->response = VIRTIO_SCSI_S_OK;
-            }
+    } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
+               type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
+        if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
+                    sizeof(VirtIOSCSICtrlANResp)) < 0) {
+            virtio_scsi_bad_req();
+        } else {
+            req->resp.an.event_actual = 0;
+            req->resp.an.response = VIRTIO_SCSI_S_OK;

         }
         }

+    }
+    if (r == 0) {

         virtio_scsi_complete_req(req);
         virtio_scsi_complete_req(req);

+    } else {
+        assert(r == -EINPROGRESS);
+    }
+}
+
+static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
+    VirtIOSCSIReq *req;
+
+    if (s->ctx && !s->dataplane_disabled) {
+        virtio_scsi_dataplane_start(s);
+        return;

     }
     }

+    while ((req = virtio_scsi_pop_req(s, vq))) {
+        virtio_scsi_handle_ctrl_req(s, req);
+    }
+}
+
+static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
+{
+    /* Sense data is not in req->resp and is copied separately
+     * in virtio_scsi_command_complete.
+     */
+    req->resp_size = sizeof(VirtIOSCSICmdResp);
+    virtio_scsi_complete_req(req);

 }
 
 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
                                          size_t resid)
 {
     VirtIOSCSIReq *req = r->hba_private;
 }
 
 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
                                          size_t resid)
 {
     VirtIOSCSIReq *req = r->hba_private;

-    VirtIOSCSI *s = req->dev;
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
+    uint8_t sense[SCSI_SENSE_BUF_SIZE];

     uint32_t sense_len;
     uint32_t sense_len;

+    VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);

 
     if (r->io_canceled) {
         return;
     }
 
 
     if (r->io_canceled) {
         return;
     }
 

-    req->resp.cmd->response = VIRTIO_SCSI_S_OK;
-    req->resp.cmd->status = status;
-    if (req->resp.cmd->status == GOOD) {
-        req->resp.cmd->resid = tswap32(resid);
+    req->resp.cmd.response = VIRTIO_SCSI_S_OK;
+    req->resp.cmd.status = status;
+    if (req->resp.cmd.status == GOOD) {
+        req->resp.cmd.resid = virtio_tswap32(vdev, resid);

     } else {
     } else {

-        req->resp.cmd->resid = 0;
-        sense_len = scsi_req_get_sense(r, req->resp.cmd->sense,
-                                       vs->sense_size);
-        req->resp.cmd->sense_len = tswap32(sense_len);
+        req->resp.cmd.resid = 0;
+        sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
+        sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
+        qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
+                            sense, sense_len);
+        req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);

     }
     }

-    virtio_scsi_complete_req(req);
+    virtio_scsi_complete_cmd_req(req);
+}
+
+static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
+                                 uint8_t *buf, void *hba_private)
+{
+    VirtIOSCSIReq *req = hba_private;
+
+    if (cmd->len == 0) {
+        cmd->len = MIN(VIRTIO_SCSI_CDB_SIZE, SCSI_CMD_BUF_SIZE);
+        memcpy(cmd->buf, buf, cmd->len);
+    }
+
+    /* Extract the direction and mode directly from the request, for
+     * host device passthrough.
+     */
+    cmd->xfer = req->qsgl.size;
+    cmd->mode = req->mode;
+    return 0;

 }
 
 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
 }
 
 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)


@@ -381,69 +505,93 @@ static void virtio_scsi_request_cancelled(SCSIRequest *r)
         return;
     }
     if (req->dev->resetting) {
         return;
     }
     if (req->dev->resetting) {

-        req->resp.cmd->response = VIRTIO_SCSI_S_RESET;
+        req->resp.cmd.response = VIRTIO_SCSI_S_RESET;

     } else {
     } else {

-        req->resp.cmd->response = VIRTIO_SCSI_S_ABORTED;
+        req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;

     }
     }

-    virtio_scsi_complete_req(req);
+    virtio_scsi_complete_cmd_req(req);

 }
 
 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 {
 }
 
 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
 {

-    req->resp.cmd->response = VIRTIO_SCSI_S_FAILURE;
-    virtio_scsi_complete_req(req);
+    req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
+    virtio_scsi_complete_cmd_req(req);

 }
 
 }
 

-static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
+bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)

 {
 {

-    /* use non-QOM casts in the data path */
-    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

     VirtIOSCSICommon *vs = &s->parent_obj;
     VirtIOSCSICommon *vs = &s->parent_obj;

+    SCSIDevice *d;
+    int rc;

 
 

-    VirtIOSCSIReq *req;
-    int n;
-
-    while ((req = virtio_scsi_pop_req(s, vq))) {
-        SCSIDevice *d;
-        int rc;
-        if (req->elem.out_num > 1 && req->elem.in_num > 1) {
+    rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
+                               sizeof(VirtIOSCSICmdResp) + vs->sense_size);
+    if (rc < 0) {
+        if (rc == -ENOTSUP) {

             virtio_scsi_fail_cmd_req(req);
             virtio_scsi_fail_cmd_req(req);

-            continue;
-        }
-
-        rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
-                                   sizeof(VirtIOSCSICmdResp) + vs->sense_size);
-        if (rc < 0) {
+        } else {

             virtio_scsi_bad_req();
         }
             virtio_scsi_bad_req();
         }

+        return false;
+    }

 
 

-        d = virtio_scsi_device_find(s, req->req.cmd->lun);
-        if (!d) {
-            req->resp.cmd->response = VIRTIO_SCSI_S_BAD_TARGET;
-            virtio_scsi_complete_req(req);
-            continue;
-        }
-        req->sreq = scsi_req_new(d, req->req.cmd->tag,
-                                 virtio_scsi_get_lun(req->req.cmd->lun),
-                                 req->req.cmd->cdb, req);
-
-        if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
-            int req_mode =
-                (req->elem.in_num > 1 ? SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV);
-
-            if (req->sreq->cmd.mode != req_mode ||
-                req->sreq->cmd.xfer > req->qsgl.size) {
-                req->resp.cmd->response = VIRTIO_SCSI_S_OVERRUN;
-                virtio_scsi_complete_req(req);
-                continue;
-            }
-        }
+    d = virtio_scsi_device_find(s, req->req.cmd.lun);
+    if (!d) {
+        req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
+        virtio_scsi_complete_cmd_req(req);
+        return false;
+    }
+    if (s->dataplane_started && blk_get_aio_context(d->conf.blk) != s->ctx) {
+        aio_context_acquire(s->ctx);
+        blk_set_aio_context(d->conf.blk, s->ctx);
+        aio_context_release(s->ctx);
+    }
+    req->sreq = scsi_req_new(d, req->req.cmd.tag,
+                             virtio_scsi_get_lun(req->req.cmd.lun),
+                             req->req.cdb, req);

 
 

-        n = scsi_req_enqueue(req->sreq);
-        if (n) {
-            scsi_req_continue(req->sreq);
+    if (req->sreq->cmd.mode != SCSI_XFER_NONE
+        && (req->sreq->cmd.mode != req->mode ||
+            req->sreq->cmd.xfer > req->qsgl.size)) {
+        req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
+        virtio_scsi_complete_cmd_req(req);
+        return false;
+    }
+    scsi_req_ref(req->sreq);
+    blk_io_plug(d->conf.blk);
+    return true;
+}
+
+void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
+{
+    SCSIRequest *sreq = req->sreq;
+    if (scsi_req_enqueue(sreq)) {
+        scsi_req_continue(sreq);
+    }
+    blk_io_unplug(sreq->dev->conf.blk);
+    scsi_req_unref(sreq);
+}
+
+static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
+{
+    /* use non-QOM casts in the data path */
+    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
+    VirtIOSCSIReq *req, *next;
+    QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
+
+    if (s->ctx && !s->dataplane_disabled) {
+        virtio_scsi_dataplane_start(s);
+        return;
+    }
+    while ((req = virtio_scsi_pop_req(s, vq))) {
+        if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
+            QTAILQ_INSERT_TAIL(&reqs, req, next);

         }
     }
         }
     }

+
+    QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
+        virtio_scsi_handle_cmd_req_submit(s, req);
+    }

 }
 
 static void virtio_scsi_get_config(VirtIODevice *vdev,
 }
 
 static void virtio_scsi_get_config(VirtIODevice *vdev,


@@ -452,16 +600,16 @@ static void virtio_scsi_get_config(VirtIODevice *vdev,
     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 
     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 

-    stl_p(&scsiconf->num_queues, s->conf.num_queues);
-    stl_p(&scsiconf->seg_max, 128 - 2);
-    stl_p(&scsiconf->max_sectors, s->conf.max_sectors);
-    stl_p(&scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
-    stl_p(&scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
-    stl_p(&scsiconf->sense_size, s->sense_size);
-    stl_p(&scsiconf->cdb_size, s->cdb_size);
-    stw_p(&scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
-    stw_p(&scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
-    stl_p(&scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
+    virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
+    virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
+    virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
+    virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
+    virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
+    virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
+    virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
+    virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
+    virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
+    virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);

 }
 
 static void virtio_scsi_set_config(VirtIODevice *vdev,
 }
 
 static void virtio_scsi_set_config(VirtIODevice *vdev,


@@ -470,14 +618,14 @@ static void virtio_scsi_set_config(VirtIODevice *vdev,
     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 
     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 

-    if ((uint32_t) ldl_p(&scsiconf->sense_size) >= 65536 ||
-        (uint32_t) ldl_p(&scsiconf->cdb_size) >= 256) {
+    if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
+        (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {

         error_report("bad data written to virtio-scsi configuration space");
         exit(1);
     }
 
         error_report("bad data written to virtio-scsi configuration space");
         exit(1);
     }
 

-    vs->sense_size = ldl_p(&scsiconf->sense_size);
-    vs->cdb_size = ldl_p(&scsiconf->cdb_size);
+    vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
+    vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);

 }
 
 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
 }
 
 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,


@@ -491,6 +639,9 @@ static void virtio_scsi_reset(VirtIODevice *vdev)
     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 
     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 

+    if (s->ctx) {
+        virtio_scsi_dataplane_stop(s);
+    }

     s->resetting++;
     qbus_reset_all(&s->bus.qbus);
     s->resetting--;
     s->resetting++;
     qbus_reset_all(&s->bus.qbus);
     s->resetting--;


@@ -514,34 +665,38 @@ static int virtio_scsi_load(QEMUFile *f, void *opaque, int version_id)
     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
     int ret;
 
     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
     int ret;
 

-    ret = virtio_load(vdev, f);
+    ret = virtio_load(vdev, f, version_id);

     if (ret) {
         return ret;
     }
     return 0;
 }
 
     if (ret) {
         return ret;
     }
     return 0;
 }
 

-static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
-                                   uint32_t event, uint32_t reason)
+void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
+                            uint32_t event, uint32_t reason)

 {
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
     VirtIOSCSIReq *req;
     VirtIOSCSIEvent *evt;
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 {
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
     VirtIOSCSIReq *req;
     VirtIOSCSIEvent *evt;
     VirtIODevice *vdev = VIRTIO_DEVICE(s);

-    int in_size;

 
     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
         return;
     }
 
 
     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
         return;
     }
 

-    req = virtio_scsi_pop_req(s, vs->event_vq);
-    if (!req) {
-        s->events_dropped = true;
-        return;
+    if (s->dataplane_started) {
+        assert(s->ctx);
+        aio_context_acquire(s->ctx);

     }
 
     }
 

-    if (req->elem.out_num || req->elem.in_num != 1) {
-        virtio_scsi_bad_req();
+    if (s->dataplane_started) {
+        req = virtio_scsi_pop_req_vring(s, s->event_vring);
+    } else {
+        req = virtio_scsi_pop_req(s, vs->event_vq);
+    }
+    if (!req) {
+        s->events_dropped = true;
+        goto out;

     }
 
     if (s->events_dropped) {
     }
 
     if (s->events_dropped) {


@@ -549,15 +704,14 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
         s->events_dropped = false;
     }
 
         s->events_dropped = false;
     }
 

-    in_size = req->elem.in_sg[0].iov_len;
-    if (in_size < sizeof(VirtIOSCSIEvent)) {
+    if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {

         virtio_scsi_bad_req();
     }
 
         virtio_scsi_bad_req();
     }
 

-    evt = req->resp.event;
+    evt = &req->resp.event;

     memset(evt, 0, sizeof(VirtIOSCSIEvent));
     memset(evt, 0, sizeof(VirtIOSCSIEvent));

-    evt->event = event;
-    evt->reason = reason;
+    evt->event = virtio_tswap32(vdev, event);
+    evt->reason = virtio_tswap32(vdev, reason);

     if (!dev) {
         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
     } else {
     if (!dev) {
         assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
     } else {


@@ -571,12 +725,20 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
         evt->lun[3] = dev->lun & 0xFF;
     }
     virtio_scsi_complete_req(req);
         evt->lun[3] = dev->lun & 0xFF;
     }
     virtio_scsi_complete_req(req);

+out:
+    if (s->dataplane_started) {
+        aio_context_release(s->ctx);
+    }

 }
 
 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 {
     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 
 }
 
 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 {
     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 

+    if (s->ctx && !s->dataplane_disabled) {
+        virtio_scsi_dataplane_start(s);
+        return;
+    }

     if (s->events_dropped) {
         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
     }
     if (s->events_dropped) {
         virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
     }


@@ -587,33 +749,51 @@ static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 
     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 

-    if (((vdev->guest_features >> VIRTIO_SCSI_F_CHANGE) & 1) &&
+    if (virtio_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&

         dev->type != TYPE_ROM) {
         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
                                sense.asc | (sense.ascq << 8));
     }
 }
 
         dev->type != TYPE_ROM) {
         virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
                                sense.asc | (sense.ascq << 8));
     }
 }
 

-static void virtio_scsi_hotplug(SCSIBus *bus, SCSIDevice *dev)
+static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
+                                Error **errp)

 {
 {

-    VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
-    VirtIODevice *vdev = VIRTIO_DEVICE(s);
+    VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+    SCSIDevice *sd = SCSI_DEVICE(dev);
+
+    if (s->ctx && !s->dataplane_disabled) {
+        if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
+            return;
+        }
+        blk_op_block_all(sd->conf.blk, s->blocker);
+    }

 
 

-    if ((vdev->guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
-        virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
+    if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
+        virtio_scsi_push_event(s, sd,
+                               VIRTIO_SCSI_T_TRANSPORT_RESET,

                                VIRTIO_SCSI_EVT_RESET_RESCAN);
     }
 }
 
                                VIRTIO_SCSI_EVT_RESET_RESCAN);
     }
 }
 

-static void virtio_scsi_hot_unplug(SCSIBus *bus, SCSIDevice *dev)
+static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
+                                  Error **errp)

 {
 {

-    VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
-    VirtIODevice *vdev = VIRTIO_DEVICE(s);
+    VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+    SCSIDevice *sd = SCSI_DEVICE(dev);

 
 

-    if ((vdev->guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
-        virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
+    if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
+        virtio_scsi_push_event(s, sd,
+                               VIRTIO_SCSI_T_TRANSPORT_RESET,

                                VIRTIO_SCSI_EVT_RESET_REMOVED);
     }
                                VIRTIO_SCSI_EVT_RESET_REMOVED);
     }

+
+    if (s->ctx) {
+        blk_op_unblock_all(sd->conf.blk, s->blocker);
+    }
+    qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);

 }
 
 static struct SCSIBusInfo virtio_scsi_scsi_info = {
 }
 
 static struct SCSIBusInfo virtio_scsi_scsi_info = {


@@ -625,14 +805,15 @@ static struct SCSIBusInfo virtio_scsi_scsi_info = {
     .complete = virtio_scsi_command_complete,
     .cancel = virtio_scsi_request_cancelled,
     .change = virtio_scsi_change,
     .complete = virtio_scsi_command_complete,
     .cancel = virtio_scsi_request_cancelled,
     .change = virtio_scsi_change,

-    .hotplug = virtio_scsi_hotplug,
-    .hot_unplug = virtio_scsi_hot_unplug,
+    .parse_cdb = virtio_scsi_parse_cdb,

     .get_sg_list = virtio_scsi_get_sg_list,
     .save_request = virtio_scsi_save_request,
     .load_request = virtio_scsi_load_request,
 };
 
     .get_sg_list = virtio_scsi_get_sg_list,
     .save_request = virtio_scsi_save_request,
     .load_request = virtio_scsi_load_request,
 };
 

-void virtio_scsi_common_realize(DeviceState *dev, Error **errp)
+void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
+                                HandleOutput ctrl, HandleOutput evt,
+                                HandleOutput cmd)

 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);


@@ -641,17 +822,54 @@ void virtio_scsi_common_realize(DeviceState *dev, Error **errp)
     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
                 sizeof(VirtIOSCSIConfig));
 
     virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
                 sizeof(VirtIOSCSIConfig));
 

-    s->cmd_vqs = g_malloc0(s->conf.num_queues * sizeof(VirtQueue *));
+    if (s->conf.num_queues == 0 ||
+            s->conf.num_queues > VIRTIO_PCI_QUEUE_MAX - 2) {
+        error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
+                         "must be a positive integer less than %d.",
+                   s->conf.num_queues, VIRTIO_PCI_QUEUE_MAX - 2);
+        virtio_cleanup(vdev);
+        return;
+    }
+    s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);

     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 
     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
     s->sense_size = VIRTIO_SCSI_SENSE_SIZE;
     s->cdb_size = VIRTIO_SCSI_CDB_SIZE;
 
     s->ctrl_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,

-                                  virtio_scsi_handle_ctrl);
+                                  ctrl);

     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
     s->event_vq = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,

-                                   virtio_scsi_handle_event);
+                                   evt);

     for (i = 0; i < s->conf.num_queues; i++) {
         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,
     for (i = 0; i < s->conf.num_queues; i++) {
         s->cmd_vqs[i] = virtio_add_queue(vdev, VIRTIO_SCSI_VQ_SIZE,

-                                         virtio_scsi_handle_cmd);
+                                         cmd);
+    }
+
+    if (s->conf.iothread) {
+        virtio_scsi_set_iothread(VIRTIO_SCSI(s), s->conf.iothread);
+    }
+}
+
+/* Disable dataplane thread during live migration since it does not
+ * update the dirty memory bitmap yet.
+ */
+static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
+{
+    VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
+                                 migration_state_notifier);
+    MigrationState *mig = data;
+
+    if (migration_in_setup(mig)) {
+        if (!s->dataplane_started) {
+            return;
+        }
+        virtio_scsi_dataplane_stop(s);
+        s->dataplane_disabled = true;
+    } else if (migration_has_finished(mig) ||
+               migration_has_failed(mig)) {
+        if (s->dataplane_started) {
+            return;
+        }
+        blk_drain_all(); /* complete in-flight non-dataplane requests */
+        s->dataplane_disabled = false;

     }
 }
 
     }
 }
 


@@ -662,7 +880,9 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
     static int virtio_scsi_id;
     Error *err = NULL;
 
     static int virtio_scsi_id;
     Error *err = NULL;
 

-    virtio_scsi_common_realize(dev, &err);
+    virtio_scsi_common_realize(dev, &err, virtio_scsi_handle_ctrl,
+                               virtio_scsi_handle_event,
+                               virtio_scsi_handle_cmd);

     if (err != NULL) {
         error_propagate(errp, err);
         return;
     if (err != NULL) {
         error_propagate(errp, err);
         return;


@@ -670,6 +890,8 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 
     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
                  &virtio_scsi_scsi_info, vdev->bus_name);
 
     scsi_bus_new(&s->bus, sizeof(s->bus), dev,
                  &virtio_scsi_scsi_info, vdev->bus_name);

+    /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
+    qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort);

 
     if (!dev->hotplugged) {
         scsi_bus_legacy_handle_cmdline(&s->bus, &err);
 
     if (!dev->hotplugged) {
         scsi_bus_legacy_handle_cmdline(&s->bus, &err);


@@ -681,6 +903,18 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 
     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
                     virtio_scsi_save, virtio_scsi_load, s);
 
     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
                     virtio_scsi_save, virtio_scsi_load, s);

+    s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
+    add_migration_state_change_notifier(&s->migration_state_notifier);
+}
+
+static void virtio_scsi_instance_init(Object *obj)
+{
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
+
+    object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
+                             (Object **)&vs->conf.iothread,
+                             qdev_prop_allow_set_link_before_realize,
+                             OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);

 }
 
 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)
 }
 
 void virtio_scsi_common_unrealize(DeviceState *dev, Error **errp)


@@ -697,6 +931,7 @@ static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 
     unregister_savevm(dev, "virtio-scsi", s);
     VirtIOSCSI *s = VIRTIO_SCSI(dev);
 
     unregister_savevm(dev, "virtio-scsi", s);

+    remove_migration_state_change_notifier(&s->migration_state_notifier);

 
     virtio_scsi_common_unrealize(dev, errp);
 }
 
     virtio_scsi_common_unrealize(dev, errp);
 }


@@ -719,6 +954,7 @@ static void virtio_scsi_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);

+    HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);

 
     dc->props = virtio_scsi_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 
     dc->props = virtio_scsi_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);


@@ -727,6 +963,8 @@ static void virtio_scsi_class_init(ObjectClass *klass, void *data)
     vdc->set_config = virtio_scsi_set_config;
     vdc->get_features = virtio_scsi_get_features;
     vdc->reset = virtio_scsi_reset;
     vdc->set_config = virtio_scsi_set_config;
     vdc->get_features = virtio_scsi_get_features;
     vdc->reset = virtio_scsi_reset;

+    hc->plug = virtio_scsi_hotplug;
+    hc->unplug = virtio_scsi_hotunplug;

 }
 
 static const TypeInfo virtio_scsi_common_info = {
 }
 
 static const TypeInfo virtio_scsi_common_info = {


@@ -741,7 +979,12 @@ static const TypeInfo virtio_scsi_info = {
     .name = TYPE_VIRTIO_SCSI,
     .parent = TYPE_VIRTIO_SCSI_COMMON,
     .instance_size = sizeof(VirtIOSCSI),
     .name = TYPE_VIRTIO_SCSI,
     .parent = TYPE_VIRTIO_SCSI_COMMON,
     .instance_size = sizeof(VirtIOSCSI),

+    .instance_init = virtio_scsi_instance_init,

     .class_init = virtio_scsi_class_init,
     .class_init = virtio_scsi_class_init,

+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_HOTPLUG_HANDLER },
+        { }
+    }

 };
 
 static void virtio_register_types(void)
 };
 
 static void virtio_register_types(void)