Commit 6aa46d8f authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Michael S. Tsirkin
Browse files

virtio: move VirtQueueElement at the beginning of the structs 



The next patch will make virtqueue_pop/vring_pop allocate memory for
the VirtQueueElement. In some cases (blk, scsi, gpu) the device wants
to extend VirtQueueElement with device-specific fields and, until now,
the place of the VirtQueueElement within the containing struct didn't
matter. When allocating the entire block in virtqueue_pop/vring_pop,
however, the containing struct must basically be a "subclass" of
VirtQueueElement, with the VirtQueueElement as the first field. Make
that the case for blk and scsi; gpu is already doing it.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent 0734fb08

hw/scsi/virtio-scsi.c

+1 −2
Original line number Diff line number Diff line
@@ -45,8 +45,7 @@ VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq) 
{

    VirtIOSCSIReq *req;

    VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;

    const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)

                             + sizeof(VirtQueueElement);

    const size_t zero_skip = offsetof(VirtIOSCSIReq, vring);



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

    req->vq = vq;

include/hw/virtio/virtio-blk.h

+1 −1
Original line number Diff line number Diff line
@@ -60,9 +60,9 @@ typedef struct VirtIOBlock { 
} VirtIOBlock;



typedef struct VirtIOBlockReq {

    VirtQueueElement elem;

    int64_t sector_num;

    VirtIOBlock *dev;

    VirtQueueElement elem;

    struct virtio_blk_inhdr *in;

    struct virtio_blk_outhdr out;

    QEMUIOVector qiov;

include/hw/virtio/virtio-scsi.h

+6 −7
Original line number Diff line number Diff line
@@ -112,18 +112,17 @@ typedef struct VirtIOSCSI { 
} VirtIOSCSI;



typedef struct VirtIOSCSIReq {

    /* Note:

     * - fields up to resp_iov are initialized by virtio_scsi_init_req;

     * - fields starting at vring are zeroed by virtio_scsi_init_req.

     * */

    VirtQueueElement elem;



    VirtIOSCSI *dev;

    VirtQueue *vq;

    QEMUSGList qsgl;

    QEMUIOVector resp_iov;



    /* Note:

     * - fields before elem are initialized by virtio_scsi_init_req;

     * - elem is uninitialized at the time of allocation.

     * - fields after elem are zeroed by virtio_scsi_init_req.

     * */



    VirtQueueElement elem;

    /* Set by dataplane code. */

    VirtIOSCSIVring *vring;