Rusty Russell <rusty@xxxxxxxxxxxxxxx> writes:
> virtio_add_buf() is going away, replaced with virtio_add_sgs() which
> takes multiple terminated scatterlists.
>
> Cc: Eric Van Hensbergen <ericvh@xxxxxxxxx>
> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
This one was buggy. Testing and reading the patch do wonderful things.
Cheers,
Rusty.
9p/trans_virtio.c: use virtio_add_sgs[]
virtio_add_buf() is going away, replaced with virtio_add_sgs() which
takes multiple terminated scatterlists.
Cc: Eric Van Hensbergen <ericvh@xxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index de2e950..e29d72e 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -194,11 +194,14 @@ static int pack_sg_list(struct scatterlist *sg, int start,
if (s > count)
s = count;
BUG_ON(index > limit);
+ /* Make sure we don't terminate early. */
+ sg_unmark_end(&sg[index]);
sg_set_buf(&sg[index++], data, s);
count -= s;
data += s;
}
-
+ if (index-start)
+ sg_mark_end(&sg[index - 1]);
return index-start;
}
@@ -236,12 +239,17 @@ pack_sg_list_p(struct scatterlist *sg, int start, int limit,
s = rest_of_page(data);
if (s > count)
s = count;
+ /* Make sure we don't terminate early. */
+ sg_unmark_end(&sg[index]);
sg_set_page(&sg[index++], pdata[i++], s, data_off);
data_off = 0;
data += s;
count -= s;
nr_pages--;
}
+
+ if (index-start)
+ sg_mark_end(&sg[index - 1]);
return index - start;
}
@@ -256,9 +264,10 @@ static int
p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
{
int err;
- int in, out;
+ int in, out, out_sgs, in_sgs;
unsigned long flags;
struct virtio_chan *chan = client->trans;
+ struct scatterlist *sgs[2];
p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
@@ -266,15 +275,20 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
req_retry:
spin_lock_irqsave(&chan->lock, flags);
+ out_sgs = in_sgs = 0;
/* Handle out VirtIO ring buffers */
out = pack_sg_list(chan->sg, 0,
VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
+ if (out)
+ sgs[out_sgs++] = chan->sg;
in = pack_sg_list(chan->sg, out,
VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
+ if (in)
+ sgs[out_sgs + in_sgs++] = chan->sg + out;
- err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc,
+ err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
GFP_ATOMIC);
if (err < 0) {
if (err == -ENOSPC) {
chan->ring_bufs_avail = 0;
@@ -289,7 +304,7 @@ req_retry:
} else {
spin_unlock_irqrestore(&chan->lock, flags);
p9_debug(P9_DEBUG_TRANS,
- "virtio rpc add_buf returned failure\n");
+ "virtio rpc add_sgs returned failure\n");
return -EIO;
}
}
@@ -351,11 +366,12 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
char *uidata, char *uodata, int inlen,
int outlen, int in_hdr_len, int kern_buf)
{
- int in, out, err;
+ int in, out, err, out_sgs, in_sgs;
unsigned long flags;
int in_nr_pages = 0, out_nr_pages = 0;
struct page **in_pages = NULL, **out_pages = NULL;
struct virtio_chan *chan = client->trans;
+ struct scatterlist *sgs[4];
p9_debug(P9_DEBUG_TRANS, "virtio request\n");
@@ -396,13 +412,22 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
req->status = REQ_STATUS_SENT;
req_retry_pinned:
spin_lock_irqsave(&chan->lock, flags);
+
+ out_sgs = in_sgs = 0;
+
/* out data */
out = pack_sg_list(chan->sg, 0,
VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
- if (out_pages)
+ if (out)
+ sgs[out_sgs++] = chan->sg;
+
+ if (out_pages) {
+ sgs[out_sgs++] = chan->sg + out;
out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
out_pages, out_nr_pages, uodata, outlen);
+ }
+
/*
* Take care of in data
* For example TREAD have 11.
@@ -412,11 +437,17 @@ req_retry_pinned:
*/
in = pack_sg_list(chan->sg, out,
VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
- if (in_pages)
+ if (in)
+ sgs[out_sgs + in_sgs++] = chan->sg + out;
+
+ if (in_pages) {
+ sgs[out_sgs + in_sgs++] = chan->sg + out + in;
in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
in_pages, in_nr_pages, uidata, inlen);
+ }
- err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc,
+ BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
+ err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
GFP_ATOMIC);
if (err < 0) {
if (err == -ENOSPC) {
@@ -432,7 +463,7 @@ req_retry_pinned:
} else {
spin_unlock_irqrestore(&chan->lock, flags);
p9_debug(P9_DEBUG_TRANS,
- "virtio rpc add_buf returned failure\n");
+ "virtio rpc add_sgs returned failure\n");
err = -EIO;
goto err_out;
}
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
