On Sat, 6 May 2023 08:08:02 -0400, Feng Liu <feliu@xxxxxxxxxx> wrote:
>
>
> On 2023-05-05 p.m.10:33, Xuan Zhuo wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > On Tue, 2 May 2023 20:35:25 -0400, Feng Liu <feliu@xxxxxxxxxx> wrote:
> >> When initializing XDP in virtnet_open(), some rq xdp initialization
> >> may hit an error causing net device open failed. However, previous
> >> rqs have already initialized XDP and enabled NAPI, which is not the
> >> expected behavior. Need to roll back the previous rq initialization
> >> to avoid leaks in error unwinding of init code.
> >>
> >> Also extract a helper function of disable queue pairs, and use newly
> >> introduced helper function in error unwinding and virtnet_close;
> >>
> >> Issue: 3383038
> >> Fixes: 754b8a21a96d ("virtio_net: setup xdp_rxq_info")
> >> Signed-off-by: Feng Liu <feliu@xxxxxxxxxx>
> >> Reviewed-by: William Tu <witu@xxxxxxxxxx>
> >> Reviewed-by: Parav Pandit <parav@xxxxxxxxxx>
> >> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
> >> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> >> Change-Id: Ib4c6a97cb7b837cfa484c593dd43a435c47ea68f
> >> ---
> >> drivers/net/virtio_net.c | 30 ++++++++++++++++++++----------
> >> 1 file changed, 20 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >> index 8d8038538fc4..3737cf120cb7 100644
> >> --- a/drivers/net/virtio_net.c
> >> +++ b/drivers/net/virtio_net.c
> >> @@ -1868,6 +1868,13 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
> >> return received;
> >> }
> >>
> >> +static void virtnet_disable_qp(struct virtnet_info *vi, int qp_index)
> >> +{
> >> + virtnet_napi_tx_disable(&vi->sq[qp_index].napi);
> >> + napi_disable(&vi->rq[qp_index].napi);
> >> + xdp_rxq_info_unreg(&vi->rq[qp_index].xdp_rxq);
> >> +}
> >> +
> >> static int virtnet_open(struct net_device *dev)
> >> {
> >> struct virtnet_info *vi = netdev_priv(dev);
> >> @@ -1883,20 +1890,26 @@ static int virtnet_open(struct net_device *dev)
> >>
> >> err = xdp_rxq_info_reg(&vi->rq[i].xdp_rxq, dev, i, vi->rq[i].napi.napi_id);
> >> if (err < 0)
> >> - return err;
> >> + goto err_xdp_info_reg;
> >>
> >> err = xdp_rxq_info_reg_mem_model(&vi->rq[i].xdp_rxq,
> >> MEM_TYPE_PAGE_SHARED, NULL);
> >> - if (err < 0) {
> >> - xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
> >> - return err;
> >> - }
> >> + if (err < 0)
> >> + goto err_xdp_reg_mem_model;
> >>
> >> virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
> >> virtnet_napi_tx_enable(vi, vi->sq[i].vq, &vi->sq[i].napi);
> >> }
> >>
> >> return 0;
> >> +
> >> +err_xdp_reg_mem_model:
> >> + xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
> >> +err_xdp_info_reg:
> >> + for (i = i - 1; i >= 0; i--)
> >> + virtnet_disable_qp(vi, i);
> >
> >
> > I would to know should we handle for these:
> >
> > disable_delayed_refill(vi);
> > cancel_delayed_work_sync(&vi->refill);
> >
> >
> > Maybe we should call virtnet_close() with "i" directly.
> >
> > Thanks.
> >
> >
> Can’t use i directly here, because if xdp_rxq_info_reg fails, napi has
> not been enabled for current qp yet, I should roll back from the queue
> pairs where napi was enabled before(i--), otherwise it will hang at napi
> disable api
This is not the point, the key is whether we should handle with:
disable_delayed_refill(vi);
cancel_delayed_work_sync(&vi->refill);
Thanks.
>
> >> +
> >> + return err;
> >> }
> >>
> >> static int virtnet_poll_tx(struct napi_struct *napi, int budget)
> >> @@ -2305,11 +2318,8 @@ static int virtnet_close(struct net_device *dev)
> >> /* Make sure refill_work doesn't re-enable napi! */
> >> cancel_delayed_work_sync(&vi->refill);
> >>
> >> - for (i = 0; i < vi->max_queue_pairs; i++) {
> >> - virtnet_napi_tx_disable(&vi->sq[i].napi);
> >> - napi_disable(&vi->rq[i].napi);
> >> - xdp_rxq_info_unreg(&vi->rq[i].xdp_rxq);
> >> - }
> >> + for (i = 0; i < vi->max_queue_pairs; i++)
> >> + virtnet_disable_qp(vi, i);
> >>
> >> return 0;
> >> }
> >> --
> >> 2.37.1 (Apple Git-137.1)
> >>
