Hi Maxime, > -----Original Message----- > From: Ding, Xuan > Sent: Thursday, September 23, 2021 4:36 PM > To: Maxime Coquelin <[email protected]>; Xia, Chenbo > <[email protected]> > Cc: [email protected]; Hu, Jiayu <[email protected]>; Wang, Yinan > <[email protected]>; [email protected]; Liu, Yong <[email protected]> > Subject: RE: [PATCH] net/virtio: fix indirect descriptors reconnection > > Hi Maxime, > > > -----Original Message----- > > From: Maxime Coquelin <[email protected]> > > Sent: Thursday, September 23, 2021 4:16 PM > > To: Ding, Xuan <[email protected]>; Xia, Chenbo <[email protected]> > > Cc: [email protected]; Hu, Jiayu <[email protected]>; Wang, Yinan > > <[email protected]>; [email protected]; Liu, Yong <[email protected]> > > Subject: Re: [PATCH] net/virtio: fix indirect descriptors reconnection > > > > Hi Xuan, > > > > On 8/19/21 07:35, Xuan Ding wrote: > > > Since packed indirect descriptors are added and initialized when > > > initializing vring, the reconnection path also needs to be considered. > > > > > > Fixes: 381f39ebb78a ("net/virtio: fix packed ring indirect descricptors > > > setup") > > > Cc: [email protected] > > > Cc: [email protected] > > > > > > Signed-off-by: Xuan Ding <[email protected]> > > > --- > > > drivers/net/virtio/virtqueue.c | 14 ++++++++++++++ > > > 1 file changed, 14 insertions(+) > > > > > > diff --git a/drivers/net/virtio/virtqueue.c > > > b/drivers/net/virtio/virtqueue.c > > > index 1f9af3c31b..47229f35c4 100644 > > > --- a/drivers/net/virtio/virtqueue.c > > > +++ b/drivers/net/virtio/virtqueue.c > > > @@ -208,6 +208,20 @@ virtqueue_txvq_reset_packed(struct virtqueue *vq) > > > rte_pktmbuf_free(dxp->cookie); > > > dxp->cookie = NULL; > > > } > > > > It makes me think we might save quite some bytes by not allocating > > indirect descriptors when feature is not negotiated, but it might have > > a cost in term of performance. > > Do you mean we allocate the indirect descriptors after checking the indirect > feature in virtio TX queue, > instead of allocating it at initialization? > If so, that makes sense, and hence we don't to initialize it in two places.
Sorry for replying myself, as for performance, I can have a try and test the impact on performance. Thanks, Xuan > > > > > > + > > > + struct virtio_tx_region *txr; > > > > Don't mix declarations within code. > > > > > + txr = txvq->virtio_net_hdr_mz->addr; > > > + /* first indirect descriptor is always the tx header */ > > > + struct vring_packed_desc *start_dp = > > > + txr[desc_idx].tx_packed_indir; > > > > Ditto. > > Thanks, will update in next version. > > Regards, > Xuan > > > > > > + vring_desc_init_indirect_packed(start_dp, > > > + RTE_DIM(txr[desc_idx].tx_packed_indir)); > > > + start_dp->addr = txvq->virtio_net_hdr_mem > > > + + desc_idx * sizeof(*txr) > > > + + offsetof(struct virtio_tx_region, > > > + tx_hdr); > > > + start_dp->len = vq->hw->vtnet_hdr_size; > > > + > > > } > > > > > > vring_desc_init_packed(vq, size); > > > > > > > Thanks, > > Maxime
