From: Paolo Bonzini <pbonzini@redhat.com> To: linux-kernel@vger.kernel.org Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com>, asias@redhat.com, Rusty Russell <rusty@rustcorp.com.au>, mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [RFC PATCH 3/8] virtio-blk: use virtqueue_start_buf on bio path Date: Thu, 7 Feb 2013 13:22:27 +0100 [thread overview] Message-ID: <1360239752-2470-4-git-send-email-pbonzini@redhat.com> (raw) In-Reply-To: <1360239752-2470-1-git-send-email-pbonzini@redhat.com> Move the creation of the request header and response footer to __virtblk_add_req. vbr->sg only contains the data scatterlist, the header/footer are added separately using the new piecewise API for building virtqueue buffers. With this change, virtio-blk is not relying anymore on the virtio functions ignoring the end markers in a scatterlist. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- drivers/block/virtio_blk.c | 75 +++++++++++++++++++++++++++----------------- 1 files changed, 46 insertions(+), 29 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index fd8a689..538cc40 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -62,6 +62,7 @@ struct virtblk_req struct virtio_blk *vblk; int flags; u8 status; + int sg_count; struct scatterlist sg[]; }; @@ -100,24 +101,53 @@ static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk, return vbr; } -static inline int __virtblk_add_req(struct virtqueue *vq, - struct virtblk_req *vbr, - unsigned long out, - unsigned long in) +static int __virtblk_add_req(struct virtqueue *vq, + struct virtblk_req *vbr) { - return virtqueue_add_buf(vq, vbr->sg, out, in, vbr, GFP_ATOMIC); + struct virtqueue_buf buf; + struct scatterlist sg; + enum dma_data_direction dir; + int ret; + + unsigned int count = 2; + unsigned int count_sg = 2; + + if (vbr->sg_count) { + count_sg++; + count += vbr->sg_count; + } + + ret = virtqueue_start_buf(vq, &buf, vbr, count, count_sg, GFP_ATOMIC); + if (ret < 0) + return ret; + + dir = DMA_TO_DEVICE; + sg_init_one(&sg, &vbr->out_hdr, sizeof(vbr->out_hdr)); + virtqueue_add_sg_single(&buf, &sg, dir); + + if (vbr->sg_count) { + if ((vbr->out_hdr.type & VIRTIO_BLK_T_OUT) == 0) + dir = DMA_FROM_DEVICE; + + virtqueue_add_sg(&buf, vbr->sg, vbr->sg_count, dir); + } + + dir = DMA_FROM_DEVICE; + sg_init_one(&sg, &vbr->status, sizeof(vbr->status)); + virtqueue_add_sg_single(&buf, &sg, dir); + + virtqueue_end_buf(&buf); + return 0; } -static void virtblk_add_req(struct virtblk_req *vbr, - unsigned int out, unsigned int in) +static void virtblk_add_req(struct virtblk_req *vbr) { struct virtio_blk *vblk = vbr->vblk; DEFINE_WAIT(wait); int ret; spin_lock_irq(vblk->disk->queue->queue_lock); - while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, - out, in)) < 0)) { + while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr)) < 0)) { prepare_to_wait_exclusive(&vblk->queue_wait, &wait, TASK_UNINTERRUPTIBLE); @@ -134,22 +164,18 @@ static void virtblk_add_req(struct virtblk_req *vbr, static void virtblk_bio_send_flush(struct virtblk_req *vbr) { - unsigned int out = 0, in = 0; - vbr->flags |= VBLK_IS_FLUSH; vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH; vbr->out_hdr.sector = 0; vbr->out_hdr.ioprio = 0; - sg_set_buf(&vbr->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); - sg_set_buf(&vbr->sg[out + in++], &vbr->status, sizeof(vbr->status)); + vbr->sg_count = 0; - virtblk_add_req(vbr, out, in); + virtblk_add_req(vbr); } static void virtblk_bio_send_data(struct virtblk_req *vbr) { struct virtio_blk *vblk = vbr->vblk; - unsigned int num, out = 0, in = 0; struct bio *bio = vbr->bio; vbr->flags &= ~VBLK_IS_FLUSH; @@ -157,24 +183,15 @@ static void virtblk_bio_send_data(struct virtblk_req *vbr) vbr->out_hdr.sector = bio->bi_sector; vbr->out_hdr.ioprio = bio_prio(bio); - sg_set_buf(&vbr->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); - - num = blk_bio_map_sg(vblk->disk->queue, bio, vbr->sg + out); - - sg_set_buf(&vbr->sg[num + out + in++], &vbr->status, - sizeof(vbr->status)); - - if (num) { - if (bio->bi_rw & REQ_WRITE) { + vbr->sg_count = blk_bio_map_sg(vblk->disk->queue, bio, vbr->sg); + if (vbr->sg_count) { + if (bio->bi_rw & REQ_WRITE) vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; - out += num; - } else { + else vbr->out_hdr.type |= VIRTIO_BLK_T_IN; - in += num; - } } - virtblk_add_req(vbr, out, in); + virtblk_add_req(vbr); } static void virtblk_bio_send_data_work(struct work_struct *work) -- 1.7.1
WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com> To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, mst@redhat.com, virtualization@lists.linux-foundation.org Subject: [RFC PATCH 3/8] virtio-blk: use virtqueue_start_buf on bio path Date: Thu, 7 Feb 2013 13:22:27 +0100 [thread overview] Message-ID: <1360239752-2470-4-git-send-email-pbonzini@redhat.com> (raw) In-Reply-To: <1360239752-2470-1-git-send-email-pbonzini@redhat.com> Move the creation of the request header and response footer to __virtblk_add_req. vbr->sg only contains the data scatterlist, the header/footer are added separately using the new piecewise API for building virtqueue buffers. With this change, virtio-blk is not relying anymore on the virtio functions ignoring the end markers in a scatterlist. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- drivers/block/virtio_blk.c | 75 +++++++++++++++++++++++++++----------------- 1 files changed, 46 insertions(+), 29 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index fd8a689..538cc40 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -62,6 +62,7 @@ struct virtblk_req struct virtio_blk *vblk; int flags; u8 status; + int sg_count; struct scatterlist sg[]; }; @@ -100,24 +101,53 @@ static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk, return vbr; } -static inline int __virtblk_add_req(struct virtqueue *vq, - struct virtblk_req *vbr, - unsigned long out, - unsigned long in) +static int __virtblk_add_req(struct virtqueue *vq, + struct virtblk_req *vbr) { - return virtqueue_add_buf(vq, vbr->sg, out, in, vbr, GFP_ATOMIC); + struct virtqueue_buf buf; + struct scatterlist sg; + enum dma_data_direction dir; + int ret; + + unsigned int count = 2; + unsigned int count_sg = 2; + + if (vbr->sg_count) { + count_sg++; + count += vbr->sg_count; + } + + ret = virtqueue_start_buf(vq, &buf, vbr, count, count_sg, GFP_ATOMIC); + if (ret < 0) + return ret; + + dir = DMA_TO_DEVICE; + sg_init_one(&sg, &vbr->out_hdr, sizeof(vbr->out_hdr)); + virtqueue_add_sg_single(&buf, &sg, dir); + + if (vbr->sg_count) { + if ((vbr->out_hdr.type & VIRTIO_BLK_T_OUT) == 0) + dir = DMA_FROM_DEVICE; + + virtqueue_add_sg(&buf, vbr->sg, vbr->sg_count, dir); + } + + dir = DMA_FROM_DEVICE; + sg_init_one(&sg, &vbr->status, sizeof(vbr->status)); + virtqueue_add_sg_single(&buf, &sg, dir); + + virtqueue_end_buf(&buf); + return 0; } -static void virtblk_add_req(struct virtblk_req *vbr, - unsigned int out, unsigned int in) +static void virtblk_add_req(struct virtblk_req *vbr) { struct virtio_blk *vblk = vbr->vblk; DEFINE_WAIT(wait); int ret; spin_lock_irq(vblk->disk->queue->queue_lock); - while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, - out, in)) < 0)) { + while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr)) < 0)) { prepare_to_wait_exclusive(&vblk->queue_wait, &wait, TASK_UNINTERRUPTIBLE); @@ -134,22 +164,18 @@ static void virtblk_add_req(struct virtblk_req *vbr, static void virtblk_bio_send_flush(struct virtblk_req *vbr) { - unsigned int out = 0, in = 0; - vbr->flags |= VBLK_IS_FLUSH; vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH; vbr->out_hdr.sector = 0; vbr->out_hdr.ioprio = 0; - sg_set_buf(&vbr->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); - sg_set_buf(&vbr->sg[out + in++], &vbr->status, sizeof(vbr->status)); + vbr->sg_count = 0; - virtblk_add_req(vbr, out, in); + virtblk_add_req(vbr); } static void virtblk_bio_send_data(struct virtblk_req *vbr) { struct virtio_blk *vblk = vbr->vblk; - unsigned int num, out = 0, in = 0; struct bio *bio = vbr->bio; vbr->flags &= ~VBLK_IS_FLUSH; @@ -157,24 +183,15 @@ static void virtblk_bio_send_data(struct virtblk_req *vbr) vbr->out_hdr.sector = bio->bi_sector; vbr->out_hdr.ioprio = bio_prio(bio); - sg_set_buf(&vbr->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); - - num = blk_bio_map_sg(vblk->disk->queue, bio, vbr->sg + out); - - sg_set_buf(&vbr->sg[num + out + in++], &vbr->status, - sizeof(vbr->status)); - - if (num) { - if (bio->bi_rw & REQ_WRITE) { + vbr->sg_count = blk_bio_map_sg(vblk->disk->queue, bio, vbr->sg); + if (vbr->sg_count) { + if (bio->bi_rw & REQ_WRITE) vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; - out += num; - } else { + else vbr->out_hdr.type |= VIRTIO_BLK_T_IN; - in += num; - } } - virtblk_add_req(vbr, out, in); + virtblk_add_req(vbr); } static void virtblk_bio_send_data_work(struct work_struct *work) -- 1.7.1
next prev parent reply other threads:[~2013-02-07 12:25 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-02-07 12:22 [RFC PATCH 0/8] virtio: new API for addition of buffers, scatterlist changes Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 12:22 ` [RFC PATCH 1/8] virtio: add functions for piecewise addition of buffers Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 12:22 ` [RFC PATCH 2/8] virtio-blk: reorganize virtblk_add_req Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini [this message] 2013-02-07 12:22 ` [RFC PATCH 3/8] virtio-blk: use virtqueue_start_buf on bio path Paolo Bonzini 2013-02-07 12:22 ` [RFC PATCH 4/8] virtio-blk: use virtqueue_start_buf on req path Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 12:22 ` [RFC PATCH 5/8] scatterlist: introduce sg_unmark_end Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 12:35 ` Jens Axboe 2013-02-07 12:35 ` Jens Axboe 2013-02-07 12:22 ` [RFC PATCH 6/8] virtio-net: unmark scatterlist ending after virtqueue_add_buf Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 12:22 ` [RFC PATCH 7/8] virtio-scsi: use virtqueue_start_buf Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 12:22 ` [RFC PATCH 8/8] virtio: reimplement virtqueue_add_buf using new functions Paolo Bonzini 2013-02-07 12:22 ` Paolo Bonzini 2013-02-07 13:09 ` [RFC PATCH 0/8] virtio: new API for addition of buffers, scatterlist changes Michael S. Tsirkin 2013-02-07 13:09 ` Michael S. Tsirkin 2013-02-07 13:14 ` Paolo Bonzini 2013-02-07 13:14 ` Paolo Bonzini 2013-02-07 13:23 ` Michael S. Tsirkin 2013-02-07 13:23 ` Michael S. Tsirkin 2013-02-07 13:20 ` Paolo Bonzini 2013-02-07 13:20 ` Paolo Bonzini 2013-02-07 13:31 ` Michael S. Tsirkin 2013-02-07 13:31 ` Michael S. Tsirkin 2013-02-07 13:30 ` Paolo Bonzini 2013-02-07 13:30 ` Paolo Bonzini 2013-02-08 4:05 ` Rusty Russell 2013-02-08 4:05 ` Rusty Russell 2013-02-08 6:35 ` Paolo Bonzini 2013-02-08 6:35 ` Paolo Bonzini 2013-02-08 11:52 ` Jens Axboe 2013-02-08 11:52 ` Jens Axboe 2013-02-13 9:46 ` Rusty Russell 2013-02-13 9:46 ` Rusty Russell
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