Re: [PATCH RFC 2/4] vhost/vsock: split packets to send using multiple buffers

From: Stefan Hajnoczi
Date: Mon Apr 08 2019 - 05:28:17 EST


On Fri, Apr 05, 2019 at 11:36:08AM +0200, Stefano Garzarella wrote:
> On Fri, Apr 05, 2019 at 09:13:56AM +0100, Stefan Hajnoczi wrote:
> > On Thu, Apr 04, 2019 at 12:58:36PM +0200, Stefano Garzarella wrote:
> > > - vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
> > > + vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
> > > added = true;
> > >
> > > + pkt->off += payload_len;
> > > +
> > > + /* If we didn't send all the payload we can requeue the packet
> > > + * to send it with the next available buffer.
> > > + */
> > > + if (pkt->off < pkt->len) {
> > > + spin_lock_bh(&vsock->send_pkt_list_lock);
> > > + list_add(&pkt->list, &vsock->send_pkt_list);
> > > + spin_unlock_bh(&vsock->send_pkt_list_lock);
> > > + continue;
> >
> > The virtio_transport_deliver_tap_pkt() call is skipped. Packet capture
> > should see the exact packets that are delivered. I think this patch
> > will present one large packet instead of several smaller packets that
> > were actually delivered.
>
> I'll modify virtio_transport_build_skb() to take care of pkt->off
> and reading the payload size from the virtio_vsock_hdr.
> Otherwise, should I introduce another field in virtio_vsock_pkt to store
> the payload size?

I don't remember the details but I trust you'll pick a good way of doing
it.

Stefan

Attachment: signature.asc
Description: PGP signature