On Tue, 7 May 2024 14:24:19 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote: > On Fri, Apr 26, 2024 at 2:54 PM Heng Qi <hengqi@xxxxxxxxxxxxxxxxx> wrote: > > > > From: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> > > > > As the spec https://github.com/oasis-tcs/virtio-spec/commit/42f389989823039724f95bbbd243291ab0064f82 > > > > Based on the description provided in the above specification, we have > > enabled the virtio-net driver to support acquiring some response > > information from the device via the CVQ (Control Virtqueue). > > > > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> > > I wonder if we need to tweak the spec as it has: > > """ > Upon disabling and re-enabling a transmit virtqueue, the device MUST > set the coalescing parameters of the virtqueue > to those configured through the VIRTIO_NET_CTRL_NOTF_COAL_TX_SET > command, or, if the driver did not set any TX coalescing parameters, > to 0. > """ > > So for reset, this patch tells us the device would have a non-zero > default value. > > But spec tolds us after vq reset, it has a zero default value ... Maybe we add a bool or flag for driver to mark whether the user has actively configured interrupt coalescing parameters. Then we can take actions when vq reset occurs? Thanks. > > Thanks > > > > --- > > drivers/net/virtio_net.c | 24 +++++++++++++++++------- > > 1 file changed, 17 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > index 7176b956460b..3bc9b1e621db 100644 > > --- a/drivers/net/virtio_net.c > > +++ b/drivers/net/virtio_net.c > > @@ -2527,11 +2527,12 @@ static int virtnet_tx_resize(struct virtnet_info *vi, > > * supported by the hypervisor, as indicated by feature bits, should > > * never fail unless improperly formatted. > > */ > > -static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, > > - struct scatterlist *out) > > +static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8 cmd, > > + struct scatterlist *out, > > + struct scatterlist *in) > > { > > - struct scatterlist *sgs[4], hdr, stat; > > - unsigned out_num = 0, tmp; > > + struct scatterlist *sgs[5], hdr, stat; > > + u32 out_num = 0, tmp, in_num = 0; > > int ret; > > > > /* Caller should know better */ > > @@ -2549,10 +2550,13 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, > > > > /* Add return status. */ > > sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status)); > > - sgs[out_num] = &stat; > > + sgs[out_num + in_num++] = &stat; > > > > - BUG_ON(out_num + 1 > ARRAY_SIZE(sgs)); > > - ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC); > > + if (in) > > + sgs[out_num + in_num++] = in; > > + > > + BUG_ON(out_num + in_num > ARRAY_SIZE(sgs)); > > + ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, in_num, vi, GFP_ATOMIC); > > if (ret < 0) { > > dev_warn(&vi->vdev->dev, > > "Failed to add sgs for command vq: %d\n.", ret); > > @@ -2574,6 +2578,12 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, > > return vi->ctrl->status == VIRTIO_NET_OK; > > } > > > > +static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, > > + struct scatterlist *out) > > +{ > > + return virtnet_send_command_reply(vi, class, cmd, out, NULL); > > +} > > + > > static int virtnet_set_mac_address(struct net_device *dev, void *p) > > { > > struct virtnet_info *vi = netdev_priv(dev); > > -- > > 2.32.0.3.g01195cf9f > > >
