Subject: Re: [PATCH net-next v11] virtio_net: add page_pool support for buffer allocation

From: "Michael S. Tsirkin" <[email-masked]>
Date: Mon, 16 Mar 2026 06:43:58 -0400

On Mon, Mar 16, 2026 at 05:56:20AM -0400, Michael S. Tsirkin wrote:
> On Tue, Mar 10, 2026 at 11:31:04AM -0700, Vishwanath Seshagiri wrote:
> > @@ -5857,7 +5863,7 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
> >  	/* In big_packets mode, xdp cannot work, so there is no need to
> >  	 * initialize xsk of rq.
> >  	 */
> > -	if (vi->big_packets && !vi->mergeable_rx_bufs)
> > +	if (!vi->rq[qid].page_pool)
> >  		return -ENOENT;
> >  
> >  	if (qid >= vi->curr_queue_pairs)
> 
> 
> 
> It seems that a qid that exceeds curr_queue_pairs would previously get
> -EINVAL and now gets -ENOENT.

Or maybe this if (qid >= vi->curr_queue_pairs) is dead code?
I looked at it some more and I can't find a path where this
triggers.

> Maybe reorder the checks:
> 
>         if (qid >= vi->curr_queue_pairs)
>                 return -EINVAL;
> 
>         /* In big_packets mode, xdp cannot work, so there is no need to
>          * initialize xsk of rq.
>          */ 
>        if (!vi->rq[qid].page_pool)
>                return -ENOENT;
> 
> 
> Alternatively I think we can completely drop this chunk: we already seem
> to init page_pull at all times except for big packets mode, so the
> current code is fine I think.
> 
> 
> -- 
> MST