On Sat, Jun 03, 2023 at 11:49:24PM +0300, Arseniy Krasnov wrote:
This adds copying to guest's virtio buffers from non-linear skbs. Such
skbs are created by protocol layer when MSG_ZEROCOPY flags is used. It
changes call of 'copy_to_iter()' to 'skb_copy_datagram_iter()'. Second
function can read data from non-linear skb.
See commit to 'net/vmw_vsock/virtio_transport_common.c' with the same
name for more details.
I think it's okay if we report the same details here.
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
drivers/vhost/vsock.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 6578db78f0ae..b254aa4b756a 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -156,7 +156,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
}
iov_iter_init(&iov_iter, ITER_DEST, &vq->iov[out], in, iov_len);
- payload_len = skb->len;
+ payload_len = skb->len - VIRTIO_VSOCK_SKB_CB(skb)->frag_off;
Also here a variable should make the code more readable.
Stefano
hdr = virtio_vsock_hdr(skb);
/* If the packet is greater than the space available in the
@@ -197,8 +197,10 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
break;
}
- nbytes = copy_to_iter(skb->data, payload_len, &iov_iter);
- if (nbytes != payload_len) {
+ if (skb_copy_datagram_iter(skb,
+ VIRTIO_VSOCK_SKB_CB(skb)->frag_off,
+ &iov_iter,
+ payload_len)) {
kfree_skb(skb);
vq_err(vq, "Faulted on copying pkt buf\n");
break;
@@ -212,13 +214,13 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
vhost_add_used(vq, head, sizeof(*hdr) + payload_len);
added = true;
- skb_pull(skb, payload_len);
+ VIRTIO_VSOCK_SKB_CB(skb)->frag_off += payload_len;
total_len += payload_len;
/* If we didn't send all the payload we can requeue the packet
* to send it with the next available buffer.
*/
- if (skb->len > 0) {
+ if (VIRTIO_VSOCK_SKB_CB(skb)->frag_off < skb->len) {
hdr->flags |= cpu_to_le32(flags_to_restore);
/* We are queueing the same skb to handle
--
2.25.1
