Commit 87dbae5e authored by Will Deacon's avatar Will Deacon Committed by Michael S. Tsirkin
Browse files

vsock/virtio: Move length check to callers of virtio_vsock_skb_rx_put() 



virtio_vsock_skb_rx_put() only calls skb_put() if the length in the
packet header is not zero even though skb_put() handles this case
gracefully.

Remove the functionally redundant check from virtio_vsock_skb_rx_put()
and, on the assumption that this is a worthwhile optimisation for
handling credit messages, augment the existing length checks in
virtio_transport_rx_work() to elide the call for zero-length payloads.
Since the callers all have the length, extend virtio_vsock_skb_rx_put()
to take it as an additional parameter rather than fish it back out of
the packet header.

Note that the vhost code already has similar logic in
vhost_vsock_alloc_skb().

Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-4-will@kernel.org>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 0dab9248

drivers/vhost/vsock.c

+1 −1
Original line number Diff line number Diff line
@@ -375,7 +375,7 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq, 
		return NULL;

	}



	virtio_vsock_skb_rx_put(skb);

	virtio_vsock_skb_rx_put(skb, payload_len);



	nbytes = copy_from_iter(skb->data, payload_len, &iov_iter);

	if (nbytes != payload_len) {

include/linux/virtio_vsock.h

+2 −7
Original line number Diff line number Diff line
@@ -47,13 +47,8 @@ static inline void virtio_vsock_skb_clear_tap_delivered(struct sk_buff *skb) 
	VIRTIO_VSOCK_SKB_CB(skb)->tap_delivered = false;

}



static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb)

static inline void virtio_vsock_skb_rx_put(struct sk_buff *skb, u32 len)

{

	u32 len;



	len = le32_to_cpu(virtio_vsock_hdr(skb)->len);



	if (len > 0)

	skb_put(skb, len);

}

net/vmw_vsock/virtio_transport.c

+3 −1
Original line number Diff line number Diff line
@@ -656,7 +656,9 @@ static void virtio_transport_rx_work(struct work_struct *work) 
				continue;

			}



			virtio_vsock_skb_rx_put(skb);

			if (payload_len)

				virtio_vsock_skb_rx_put(skb, payload_len);



			virtio_transport_deliver_tap_pkt(skb);

			virtio_transport_recv_pkt(&virtio_transport, skb);

		}