Re: [Qemu-devel] [PATCH 0/3] net: add missing queue flush for e1000 and xen

[Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>]

On Thu, Aug 09, 2012 at 04:45:54PM +0200, Paolo Bonzini wrote:
> Luigi reminded me of these patches...
> 
> When the guests replenish the receive ring buffer, the network device
> should flush its queue of pending packets.  This is done with
> qemu_flush_queued_packets, and patches 2+3 add the missing call to
> two drivers, e1000 and xen.  More may come later---no time to test
> them now.
> 
> However, the device should not just retry delivery of packets that were
> already read from the tap device, it should also try to read more packets
> from the tap device.  The latter requires a qemu_notify_event to force
> recomputation of the fd_sets.  virtio already does this, but it is a
> layering violation; patch 1 moves the call from virtio to the network
> subsystem, so that e1000 and xen will then get it for free.
> 
> Paolo Bonzini (3):
>   net: notify iothread after flushing queue
>   e1000: flush queue whenever can_receive can go from false to true
>   xen: flush queue when getting an event
> 
>  hw/e1000.c              |  4 ++++
>  hw/virtio-net.c         |  4 ----
>  hw/xen_nic.c            |  1 +
>  net.c                   |  7 ++++++-
>  net/queue.c             |  5 +++--
>  net/queue.h             |  2 +-
>  6 file modificati, 15 inserzioni(+), 8 rimozioni(-)

Looks good for QEMU 1.2.  I'll give Jan and Stefano time to respond, if
they want.

Stefan