Il 22/05/2014 09:37, Fam Zheng ha scritto:
-static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
+int virtio_blk_handle_scsi_req(BlockDriverState *bs,
+ VirtIOBlkConf *conf,
+ VirtQueueElement *elem)
Two more comments...
please pass the VirtIOBlock * instead of bs/conf here.
{
+ int status = VIRTIO_BLK_S_OK;
+ struct virtio_scsi_inhdr *scsi = NULL;
#ifdef __linux__
- int ret;
int i;
+ struct sg_io_hdr hdr;
#endif
- int status = VIRTIO_BLK_S_OK;
/*
* We require at least one output segment each for the virtio_blk_outhdr
@@ -140,63 +142,61 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
* We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
* and the sense buffer pointer in the input segments.
*/
- if (req->elem.out_num < 2 || req->elem.in_num < 3) {
- virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
- g_free(req);
- return;
+ if (elem->out_num < 2 || elem->in_num < 3) {
+ status = VIRTIO_BLK_S_IOERR;
+ goto fail;
}
/*
* The scsi inhdr is placed in the second-to-last input segment, just
* before the regular inhdr.
*/
- req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
+ scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;
- if (!req->dev->blk.scsi) {
+ /*
+ * No support for bidirection commands yet.
+ */
+ if (elem->out_num > 2 && elem->in_num > 3) {
status = VIRTIO_BLK_S_UNSUPP;
goto fail;
}
- /*
- * No support for bidirection commands yet.
- */
- if (req->elem.out_num > 2 && req->elem.in_num > 3) {
+ if (!conf->scsi) {
status = VIRTIO_BLK_S_UNSUPP;
goto fail;
}
Swapping the two conditionals unnecessarily makes the patch bigger.
Paolo
#ifdef __linux__
- struct sg_io_hdr hdr;
memset(&hdr, 0, sizeof(struct sg_io_hdr));
hdr.interface_id = 'S';
- hdr.cmd_len = req->elem.out_sg[1].iov_len;
- hdr.cmdp = req->elem.out_sg[1].iov_base;
+ hdr.cmd_len = elem->out_sg[1].iov_len;
+ hdr.cmdp = elem->out_sg[1].iov_base;
hdr.dxfer_len = 0;
- if (req->elem.out_num > 2) {
+ if (elem->out_num > 2) {
/*
* If there are more than the minimally required 2 output segments
* there is write payload starting from the third iovec.
*/
hdr.dxfer_direction = SG_DXFER_TO_DEV;
- hdr.iovec_count = req->elem.out_num - 2;
+ hdr.iovec_count = elem->out_num - 2;
for (i = 0; i < hdr.iovec_count; i++)
- hdr.dxfer_len += req->elem.out_sg[i + 2].iov_len;
+ hdr.dxfer_len += elem->out_sg[i + 2].iov_len;
- hdr.dxferp = req->elem.out_sg + 2;
+ hdr.dxferp = elem->out_sg + 2;
- } else if (req->elem.in_num > 3) {
+ } else if (elem->in_num > 3) {
/*
* If we have more than 3 input segments the guest wants to actually
* read data.
*/
hdr.dxfer_direction = SG_DXFER_FROM_DEV;
- hdr.iovec_count = req->elem.in_num - 3;
+ hdr.iovec_count = elem->in_num - 3;
for (i = 0; i < hdr.iovec_count; i++)
- hdr.dxfer_len += req->elem.in_sg[i].iov_len;
+ hdr.dxfer_len += elem->in_sg[i].iov_len;
- hdr.dxferp = req->elem.in_sg;
+ hdr.dxferp = elem->in_sg;
} else {
/*
* Some SCSI commands don't actually transfer any data.
@@ -204,11 +204,11 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
hdr.dxfer_direction = SG_DXFER_NONE;
}
- hdr.sbp = req->elem.in_sg[req->elem.in_num - 3].iov_base;
- hdr.mx_sb_len = req->elem.in_sg[req->elem.in_num - 3].iov_len;
+ hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base;
+ hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len;
- ret = bdrv_ioctl(req->dev->bs, SG_IO, &hdr);
- if (ret) {
+ status = bdrv_ioctl(bs, SG_IO, &hdr);
+ if (status) {
status = VIRTIO_BLK_S_UNSUPP;
goto fail;
}
@@ -224,23 +224,32 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
hdr.status = CHECK_CONDITION;
}
- stl_p(&req->scsi->errors,
+ stl_p(&scsi->errors,
hdr.status | (hdr.msg_status << 8) |
(hdr.host_status << 16) | (hdr.driver_status << 24));
- stl_p(&req->scsi->residual, hdr.resid);
- stl_p(&req->scsi->sense_len, hdr.sb_len_wr);
- stl_p(&req->scsi->data_len, hdr.dxfer_len);
+ stl_p(&scsi->residual, hdr.resid);
+ stl_p(&scsi->sense_len, hdr.sb_len_wr);
+ stl_p(&scsi->data_len, hdr.dxfer_len);
- virtio_blk_req_complete(req, status);
- g_free(req);
- return;
+ return status;
#else
abort();
#endif
fail:
/* Just put anything nonzero so that the ioctl fails in the guest. */
- stl_p(&req->scsi->errors, 255);
+ if (scsi) {
+ stl_p(&scsi->errors, 255);
+ }
+ return status;
+}
+
+static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
+{
+ int status;
+
+ status = virtio_blk_handle_scsi_req(req->dev->bs, &req->dev->blk,
+ &req->elem);
virtio_blk_req_complete(req, status);
g_free(req);
}
diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h
index e4c41ff..1b00b48 100644
--- a/include/hw/virtio/virtio-blk.h
+++ b/include/hw/virtio/virtio-blk.h
@@ -155,4 +155,8 @@ typedef struct VirtIOBlock {
void virtio_blk_set_conf(DeviceState *dev, VirtIOBlkConf *blk);
+int virtio_blk_handle_scsi_req(BlockDriverState *bs,
+ VirtIOBlkConf *conf,
+ VirtQueueElement *elem);
+
#endif
