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: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
{
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;
} 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;
} 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;