Commit 1880ad4f authored by Fam Zheng's avatar Fam Zheng Committed by Paolo Bonzini
Browse files

virtio-scsi: Batched prepare for cmd reqs 



Queue the popped requests while calling
virtio_scsi_handle_cmd_req_prepare(), then submit them after all
prepared.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 359eea71

hw/scsi/virtio-scsi-dataplane.c

+7 −2
Original line number Diff line number Diff line
@@ -122,13 +122,18 @@ static void virtio_scsi_iothread_handle_cmd(EventNotifier *notifier) 
    VirtIOSCSIVring *vring = container_of(notifier,

                                          VirtIOSCSIVring, host_notifier);

    VirtIOSCSI *s = (VirtIOSCSI *)vring->parent;

    VirtIOSCSIReq *req;

    VirtIOSCSIReq *req, *next;

    QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);



    event_notifier_test_and_clear(notifier);

    while ((req = virtio_scsi_pop_req_vring(s, vring))) {

        if (virtio_scsi_handle_cmd_req_prepare(s, req)) {

            virtio_scsi_handle_cmd_req_submit(s, req);

            QTAILQ_INSERT_TAIL(&reqs, req, next);

        }

    }



    QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {

        virtio_scsi_handle_cmd_req_submit(s, req);

    }

}

hw/scsi/virtio-scsi.c

+7 −2
Original line number Diff line number Diff line
@@ -502,7 +502,8 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) 
{

    /* use non-QOM casts in the data path */

    VirtIOSCSI *s = (VirtIOSCSI *)vdev;

    VirtIOSCSIReq *req;

    VirtIOSCSIReq *req, *next;

    QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);



    if (s->ctx && !s->dataplane_disabled) {

        virtio_scsi_dataplane_start(s);
@@ -510,8 +511,12 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq) 
    }

    while ((req = virtio_scsi_pop_req(s, vq))) {

        if (virtio_scsi_handle_cmd_req_prepare(s, req)) {

            virtio_scsi_handle_cmd_req_submit(s, req);

            QTAILQ_INSERT_TAIL(&reqs, req, next);

        }

    }



    QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {

        virtio_scsi_handle_cmd_req_submit(s, req);

    }

}

include/hw/virtio/virtio-scsi.h

+4 −0
Original line number Diff line number Diff line
@@ -213,6 +213,10 @@ typedef struct VirtIOSCSIReq { 
    VirtQueueElement elem;

    /* Set by dataplane code. */

    VirtIOSCSIVring *vring;



    /* Used for two-stage request submission */

    QTAILQ_ENTRY(VirtIOSCSIReq) next;



    SCSIRequest *sreq;

    size_t resp_size;

    enum SCSIXferMode mode;