From 6aa46d8ff1ee7e9ca0c4a54d75c74108bee22124 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Sun, 31 Jan 2016 11:28:57 +0100 Subject: [PATCH] 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: Paolo Bonzini Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Cornelia Huck --- hw/scsi/virtio-scsi.c | 3 +-- include/hw/virtio/virtio-blk.h | 2 +- include/hw/virtio/virtio-scsi.h | 13 ++++++------- 3 files changed, 8 insertions(+), 10 deletions(-) diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 1500c42728..7fdf6ade98 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -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; diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index ae11a63934..403ab86166 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -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; diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h index 0394eb23de..eb9d25b9fb 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -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; -- 2.11.0