On Tue, Oct 27, 2026 at 10:53:16PM +0900, Lianjie Wang wrote:
> On Tue, Oct 27, 2026 at 01:06:41PM +0100, Paolo Abeni wrote:
> > On 10/22/26 20:26, Lianjie Wang wrote:
> > > [...]
> > > @@ -4976,6 +4977,10 @@ static int __virtnet_get_hw_stats(struct
> > > virtnet_info *vi,
> > > for (p = reply; p - reply < res_size; p +=
> > > le16_to_cpu(hdr->size)) {
> > > hdr = p;
> > > qid = le16_to_cpu(hdr->vq_index);
> > > + if ((qid < first_vq || qid > last_vq) &&
> > > + !(enable_cvq && qid == vi->max_queue_pairs * 2))
> > > + return -EINVAL;
> >
> > I think the above check could be simplified to:
> > if (qid < first_vq || qid > last_vq)
> > return -EINVAL;
> >
> > squashing the following in virtnet_get_hw_stats():
> >
> > - if (enable_cvq)
> > + if (enable_cvq) {
> > virtnet_make_stat_req(vi, ctx, req, vi->max_queue_pairs *
> > 2, &j);
> > + last_vq++;
> > + }
> >
> > (likely with some meaningful comment).
>
> Thanks for the review!
>
> I looked into this, and I think last_vq + 1 matches the control vq
> only when all queue pairs are in use. The control vq index is
> max_queue_pairs * 2, while last_vq is curr_queue_pairs * 2 - 1 for
> ethtool -S. After ethtool -L lowers the queue count, or when probe caps
> curr_queue_pairs at num_online_cpus(), last_vq + 1 is the receive vq at
> index curr_queue_pairs * 2, which is not in the request. The simplified
> check would accept a record for it. Since the ethtool -S array has
> slots for only curr_queue_pairs queue pairs, with the transmit slots at
> its end, virtnet_fill_stats() would write the counters of that record
> into the transmit slots, and can write past the end of the array.
>
> Would you like me to keep the current check or change it in some
> other way?
>
> As for the comment, I would add the following above the check in v2:
>
> /* The control vq comes after all max_queue_pairs pairs, so it
> * exceeds last_vq + 1 when fewer pairs are in use.
> */
didn't get v2 yet.
>
> Thanks,
> Lianjie Wang
