From: Asias He <asias@redhat.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH 05/16] virtio-blk: use virtqueue_add_sgs on req path
Date: Wed, 20 Feb 2013 17:20:02 +0800 [thread overview]
Message-ID: <51249542.9040008@redhat.com> (raw)
In-Reply-To: <1361260594-601-6-git-send-email-rusty@rustcorp.com.au>
On 02/19/2013 03:56 PM, Rusty Russell wrote:
> From: Paolo Bonzini <pbonzini@redhat.com>
>
> (This is a respin of Paolo Bonzini's patch, but it calls
> virtqueue_add_sgs() instead of his multi-part API).
>
> This is similar to the previous patch, but a bit more radical
> because the bio and req paths now share the buffer construction
> code. Because the req path doesn't use vbr->sg, however, we
> need to add a couple of arguments to __virtblk_add_req.
>
> We also need to teach __virtblk_add_req how to build SCSI command
> requests.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
> ---
> drivers/block/virtio_blk.c | 69 +++++++++++++++++++++-----------------------
> 1 file changed, 33 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index e27bc6c..523a70f 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -102,19 +102,40 @@ static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk,
> }
>
> static int __virtblk_add_req(struct virtqueue *vq,
> - struct virtblk_req *vbr)
> + struct virtblk_req *vbr,
> + struct scatterlist *data_sg,
> + unsigned data_nents)
> {
> - struct scatterlist hdr, tailer, *sgs[3];
> + struct scatterlist hdr, tailer, cmd, sense, inhdr, *sgs[6];
> unsigned int num_out = 0, num_in = 0;
> + int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT;
>
> sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
> sgs[num_out++] = &hdr;
>
> - if (vbr->nents) {
> + /*
> + * If this is a packet command we need a couple of additional headers.
> + * Behind the normal outhdr we put a segment with the scsi command
> + * block, and before the normal inhdr we put the sense data and the
> + * inhdr with additional status information.
> + */
> + if (type == VIRTIO_BLK_T_SCSI_CMD) {
> + sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len);
> + sgs[num_out++] = &cmd;
> + }
> +
> + if (data_nents) {
> if (vbr->out_hdr.type & VIRTIO_BLK_T_OUT)
> - sgs[num_out++] = vbr->sg;
> + sgs[num_out++] = data_sg;
> else
> - sgs[num_out + num_in++] = vbr->sg;
> + sgs[num_out + num_in++] = data_sg;
> + }
> +
> + if (type == VIRTIO_BLK_T_SCSI_CMD) {
> + sg_init_one(&sense, vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
> + sgs[num_out + num_in++] = &sense;
> + sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr));
> + sgs[num_out + num_in++] = &inhdr;
> }
>
> sg_init_one(&tailer, &vbr->status, sizeof(vbr->status));
> @@ -130,7 +151,8 @@ static void virtblk_add_req(struct virtblk_req *vbr)
> int ret;
>
> spin_lock_irq(vblk->disk->queue->queue_lock);
> - while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr)) < 0)) {
> + while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, vbr->sg,
> + vbr->nents)) < 0)) {
> prepare_to_wait_exclusive(&vblk->queue_wait, &wait,
> TASK_UNINTERRUPTIBLE);
>
> @@ -283,7 +305,7 @@ static void virtblk_done(struct virtqueue *vq)
> static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
> struct request *req)
> {
> - unsigned long num, out = 0, in = 0;
> + unsigned int num;
> struct virtblk_req *vbr;
>
> vbr = virtblk_alloc_req(vblk, GFP_ATOMIC);
> @@ -320,40 +342,15 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
> }
> }
>
> - sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
> -
> - /*
> - * If this is a packet command we need a couple of additional headers.
> - * Behind the normal outhdr we put a segment with the scsi command
> - * block, and before the normal inhdr we put the sense data and the
> - * inhdr with additional status information before the normal inhdr.
> - */
> - if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC)
> - sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len);
> -
> - num = blk_rq_map_sg(q, vbr->req, vblk->sg + out);
> -
> - if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) {
> - sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
> - sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr,
> - sizeof(vbr->in_hdr));
> - }
> -
> - sg_set_buf(&vblk->sg[num + out + in++], &vbr->status,
> - sizeof(vbr->status));
> -
> + num = blk_rq_map_sg(q, vbr->req, vblk->sg);
> if (num) {
> - if (rq_data_dir(vbr->req) == WRITE) {
> + if (rq_data_dir(vbr->req) == WRITE)
> vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
> - out += num;
> - } else {
> + else
> vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
> - in += num;
> - }
> }
>
> - if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr,
> - GFP_ATOMIC) < 0) {
> + if (__virtblk_add_req(vblk->vq, vbr, vblk->sg, num) < 0) {
> mempool_free(vbr, vblk->pool);
> return false;
> }
>
--
Asias
next prev parent reply other threads:[~2013-02-20 9:20 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-19 7:56 [PATCH 00/16] virtio ring rework Rusty Russell
2013-02-19 7:56 ` [PATCH 01/16] scatterlist: introduce sg_unmark_end Rusty Russell
2013-02-19 7:56 ` [PATCH 02/16] virtio_ring: virtqueue_add_sgs, to add multiple sgs Rusty Russell
2013-02-19 9:15 ` Wanlong Gao
2013-02-20 9:18 ` Asias He
2013-02-24 22:12 ` Michael S. Tsirkin
2013-02-26 5:14 ` Rusty Russell
2013-02-26 9:30 ` Michael S. Tsirkin
2013-02-26 7:02 ` Paolo Bonzini
2013-02-27 7:28 ` Rusty Russell
2013-02-27 7:49 ` Michael S. Tsirkin
2013-02-27 11:21 ` Rusty Russell
2013-02-28 9:24 ` Paolo Bonzini
2013-03-01 1:01 ` Rusty Russell
2013-02-19 7:56 ` [PATCH 03/16] virtio-blk: reorganize virtblk_add_req Rusty Russell
2013-02-19 7:56 ` [PATCH 04/16] virtio-blk: use virtqueue_start_buf on bio path Rusty Russell
2013-02-20 9:19 ` Asias He
2013-02-21 6:23 ` Rusty Russell
2013-02-19 7:56 ` [PATCH 05/16] virtio-blk: use virtqueue_add_sgs on req path Rusty Russell
2013-02-20 9:20 ` Asias He [this message]
2013-02-19 7:56 ` [PATCH 06/16] virtio_blk: remove nents member Rusty Russell
2013-02-20 9:20 ` Asias He
2013-02-19 7:56 ` [PATCH 07/16] virtio_ring: don't count elements twice for add_buf path Rusty Russell
2013-02-20 10:09 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 08/16] virtio_ring: virtqueue_add_outbuf / virtqueue_add_inbuf Rusty Russell
2013-02-20 10:09 ` Wanlong Gao
2013-02-21 17:09 ` Michael S. Tsirkin
2013-02-22 0:02 ` Rusty Russell
2013-02-25 21:35 ` Michael S. Tsirkin
2013-02-28 5:08 ` Rusty Russell
2013-02-28 7:01 ` Michael S. Tsirkin
2013-03-06 6:03 ` Rusty Russell
2013-02-19 7:56 ` [PATCH 09/16] virtio_net: use simplified virtqueue accessors Rusty Russell
2013-02-20 10:09 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 10/16] virtio_net: use virtqueue_add_sgs[] for command buffers Rusty Russell
2013-02-20 10:11 ` Wanlong Gao
2013-02-21 6:27 ` Rusty Russell
2013-02-21 8:30 ` Wanlong Gao
2013-02-21 9:41 ` Jason Wang
2013-02-21 9:43 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 11/16] virtio_rng: use simplified virtqueue accessors Rusty Russell
2013-02-20 10:12 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 12/16] virtio_console: " Rusty Russell
2013-02-20 10:12 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 13/16] caif_virtio: " Rusty Russell
2013-02-20 10:13 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 14/16] virtio_rpmsg_bus: " Rusty Russell
2013-02-20 10:14 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 15/16] virtio_balloon: " Rusty Russell
2013-02-20 10:15 ` Wanlong Gao
2013-02-19 7:56 ` [PATCH 16/16] 9p/trans_virtio.c: use virtio_add_sgs[] Rusty Russell
2013-02-19 9:15 ` [PATCH 00/16] virtio ring rework Paolo Bonzini
2013-02-21 6:30 ` Rusty Russell
2013-02-20 8:37 ` [PATCH 17/16] virtio-scsi: use virtqueue_add_sgs for command buffers Wanlong Gao
2013-02-20 9:38 ` Asias He
2013-02-20 9:41 ` Wanlong Gao
2013-02-20 9:47 ` [PATCH 17/16 V2] " Wanlong Gao
2013-02-20 10:54 ` Paolo Bonzini
2013-02-20 12:17 ` Asias He
2013-02-21 6:34 ` Rusty Russell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=51249542.9040008@redhat.com \
--to=asias@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=rusty@rustcorp.com.au \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).