Re: [Qemu-devel] [PATCH v11 04/12] net: merge qemu_deliver_packet and qemu_deliver_packet_iov

[Yang Hongyang]

Hi Jason,

  Thanks for the review,

On 09/22/2015 03:30 PM, Jason Wang wrote:
> On 09/16/2015 08:16 PM, Yang Hongyang wrote:
> > qemu_deliver_packet_iov already have the compat delivery, we
> > can drop qemu_deliver_packet.
> >
> > Signed-off-by: Yang Hongyang <address@hidden>
> > ---
> >   include/net/net.h |  5 -----
> >   net/net.c         | 40 +++++++---------------------------------
> >   net/queue.c       |  6 +++++-
> >   3 files changed, 12 insertions(+), 39 deletions(-)
> >
> > diff --git a/include/net/net.h b/include/net/net.h
> > index 36e5fab..7af3e15 100644
> > --- a/include/net/net.h
> > +++ b/include/net/net.h
> > @@ -152,11 +152,6 @@ void qemu_check_nic_model(NICInfo *nd, const char *model);
> >   int qemu_find_nic_model(NICInfo *nd, const char * const *models,
> >                           const char *default_model);
> >
> > -ssize_t qemu_deliver_packet(NetClientState *sender,
> > -                            unsigned flags,
> > -                            const uint8_t *data,
> > -                            size_t size,
> > -                            void *opaque);
> >   ssize_t qemu_deliver_packet_iov(NetClientState *sender,
> >                               unsigned flags,
> >                               const struct iovec *iov,
> > diff --git a/net/net.c b/net/net.c
> > index ad37419..ca35b27 100644
> > --- a/net/net.c
> > +++ b/net/net.c
> > @@ -597,36 +597,6 @@ static ssize_t filter_receive(NetClientState *nc, 
> > NetFilterChain chain,
> >       return filter_receive_iov(nc, chain, sender, flags, &iov, 1, sent_cb);
> >   }
> >
> > -ssize_t qemu_deliver_packet(NetClientState *sender,
> > -                            unsigned flags,
> > -                            const uint8_t *data,
> > -                            size_t size,
> > -                            void *opaque)
> > -{
> > -    NetClientState *nc = opaque;
> > -    ssize_t ret;
> > -
> > -    if (nc->link_down) {
> > -        return size;
> > -    }
> > -
> > -    if (nc->receive_disabled) {
> > -        return 0;
> > -    }
> > -
> > -    if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
> > -        ret = nc->info->receive_raw(nc, data, size);
> > -    } else {
> > -        ret = nc->info->receive(nc, data, size);
> > -    }
> > -
> > -    if (ret == 0) {
> > -        nc->receive_disabled = 1;
> > -    }
> > -
> > -    return ret;
> > -}
> > -
> >   void qemu_purge_queued_packets(NetClientState *nc)
> >   {
> >       if (!nc->peer) {
> > @@ -717,14 +687,18 @@ ssize_t qemu_send_packet_raw(NetClientState *nc, const 
> > uint8_t *buf, int size)
> >   }
> >
> >   static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov,
> > -                               int iovcnt)
> > +                               int iovcnt, unsigned flags)
> >   {
> >       uint8_t buffer[NET_BUFSIZE];
> >       size_t offset;
> >
> >       offset = iov_to_buf(iov, iovcnt, 0, buffer, sizeof(buffer));
> >
> > -    return nc->info->receive(nc, buffer, offset);
> > +    if (flags & QEMU_NET_PACKET_FLAG_RAW && nc->info->receive_raw) {
> > +        return nc->info->receive_raw(nc, buffer, offset);
> > +    } else {
> > +        return nc->info->receive(nc, buffer, offset);
> > +    }
>
> Then for net clients that doesn't support receive_iov, an extra memcpy
> is introduced. This seems unnecessary. And this patch looks independent,
> so please drop this patch from the series (This can also help to reduce
> the iteration). I think we may need this after all net clients support
> receive_iov().

This patch is required by the next patch which introduce a
+/* Returns:
+ *   >0 - success
+ *    0 - queue packet for future redelivery
+ *   <0 - failure (discard packet)
+ */
+typedef ssize_t (NetQueueDeliverFunc)(NetClientState *sender,
+                                      unsigned flags,
+                                      const struct iovec *iov,
+                                      int iovcnt,
+                                      void *opaque);

If we drop this patch, we will need to introduce 2 deliver func, which
seems not clean and simple.

> >   }
> >
> >   ssize_t qemu_deliver_packet_iov(NetClientState *sender,
> > @@ -747,7 +721,7 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender,
> >       if (nc->info->receive_iov) {
> >           ret = nc->info->receive_iov(nc, iov, iovcnt);
> >       } else {
> > -        ret = nc_sendv_compat(nc, iov, iovcnt);
> > +        ret = nc_sendv_compat(nc, iov, iovcnt, flags);
> >       }
> >
> >       if (ret == 0) {
> > diff --git a/net/queue.c b/net/queue.c
> > index ebbe2bb..cf8db3a 100644
> > --- a/net/queue.c
> > +++ b/net/queue.c
> > @@ -152,9 +152,13 @@ static ssize_t qemu_net_queue_deliver(NetQueue *queue,
> >                                         size_t size)
> >   {
> >       ssize_t ret = -1;
> > +    struct iovec iov = {
> > +        .iov_base = (void *)data,
> > +        .iov_len = size
> > +    };
> >
> >       queue->delivering = 1;
> > -    ret = qemu_deliver_packet(sender, flags, data, size, queue->opaque);
> > +    ret = qemu_deliver_packet_iov(sender, flags, &iov, 1, queue->opaque);
> >       queue->delivering = 0;
> >
> >       return ret;
>
>
> .

--
Thanks,
Yang.