Re: [dpdk-dev] [PATCH 1/5] net/virtio: fix vector Rx break caused by rxq flushing

[Tiwei Bie <tiwei.bie@intel.com>]

On Thu, Dec 07, 2017 at 04:00:57PM +0000, Kevin Traynor wrote:
> On 12/07/2017 05:30 AM, Tiwei Bie wrote:
> > The vector Rx will be broken if backend has consumed all
> > the descs in the avail ring before the device is started.
> > Because in current implementation, vector Rx will return
> > immediately without refilling the avail ring if the used
> > ring is empty. So we have to refill the avail ring after
> > flushing the elements in the used ring for vector Rx.
> > 
> > Besides, vector Rx has a different ring layout assumption
> > and mbuf management. So we need to handle it differently.
> > 
> 
> Hi Tiwei, does the issue only occur with the vector rx? How about if the
> simple rx is used because VIRTIO_NET_F_MRG_RXBUF is set?

Hi Kevin,

Yes, you are right! The issue only occurs with the vector
Rx. The vector Rx (i.e. the simple Rx) won't be used if
VIRTIO_NET_F_MRG_RXBUF is set.

Best regards,
Tiwei Bie