Re: [RFC 3/3] vdpasim_net: control virtqueue support

[Jason Wang]

在 2022/1/17 下午5:29, Longpeng(Mike) 写道:
> From: Longpeng <longpeng2@xxxxxxxxxx>
>
> Introduces the control virtqueue support for vdpasim_net, based on
> Jason's RFC [1].
>
> [1] https://patchwork.kernel.org/project/kvm/patch/20200924032125.18619-25-jasowang@xxxxxxxxxx/


I'd expect to implement the receive filter as well[1]. This gives us a 
chance to test this.

Thanks

[1] https://lkml.org/lkml/2020/9/23/1269


> Signed-off-by: Longpeng <longpeng2@xxxxxxxxxx>
> ---
>   drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 83 +++++++++++++++++++++++++++-
>   1 file changed, 81 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> index 76dd24abc791..e9e388fd3cff 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> @@ -26,9 +26,85 @@
>   #define DRV_LICENSE  "GPL v2"
>   
>   #define VDPASIM_NET_FEATURES	(VDPASIM_FEATURES | \
> -				 (1ULL << VIRTIO_NET_F_MAC))
> +				 (1ULL << VIRTIO_NET_F_MAC) | \
> +				 (1ULL << VIRTIO_NET_F_CTRL_VQ) | \
> +				 (1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR))
>   
> -#define VDPASIM_NET_VQ_NUM	2
> +#define VDPASIM_NET_VQ_NUM	3
> +
> +virtio_net_ctrl_ack vdpasim_net_handle_ctrl_mac(struct vdpasim *vdpasim,
> +						u8 cmd)
> +{
> +	struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
> +	virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
> +	struct virtio_net_config *config = vdpasim->config;
> +	size_t read;
> +
> +	switch (cmd) {
> +	case VIRTIO_NET_CTRL_MAC_ADDR_SET:
> +		read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->out_iov,
> +					     (void *)config->mac, ETH_ALEN);
> +		if (read == ETH_ALEN)
> +			status = VIRTIO_NET_OK;
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return status;
> +}
> +
> +static void vdpasim_net_handle_cvq(struct vdpasim *vdpasim)
> +{
> +	struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
> +	virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
> +	struct virtio_net_ctrl_hdr ctrl;
> +	size_t read, write;
> +	int err;
> +
> +	if (!(vdpasim->features & (1ULL << VIRTIO_NET_F_CTRL_VQ)))
> +		return;
> +
> +	if (!cvq->ready)
> +		return;
> +
> +	while (true) {
> +		err = vringh_getdesc_iotlb(&cvq->vring, &cvq->out_iov, &cvq->in_iov,
> +					   &cvq->head, GFP_ATOMIC);
> +		if (err <= 0)
> +			break;
> +
> +		read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl,
> +					     sizeof(ctrl));
> +		if (read != sizeof(ctrl))
> +			break;
> +
> +		switch (ctrl.class) {
> +		case VIRTIO_NET_CTRL_MAC:
> +			status = vdpasim_net_handle_ctrl_mac(vdpasim, ctrl.cmd);
> +			break;
> +		default:
> +			break;
> +		}
> +
> +		/* Make sure data is wrote before advancing index */
> +		smp_wmb();
> +
> +		write = vringh_iov_push_iotlb(&cvq->vring, &cvq->out_iov,
> +					      &status, sizeof (status));
> +		vringh_complete_iotlb(&cvq->vring, cvq->head, write);
> +		vringh_kiov_cleanup(&cvq->in_iov);
> +		vringh_kiov_cleanup(&cvq->out_iov);
> +
> +		/* Make sure used is visible before rasing the interrupt. */
> +		smp_wmb();
> +
> +		local_bh_disable();
> +		if (vringh_need_notify_iotlb(&cvq->vring) > 0)
> +			vringh_notify(&cvq->vring);
> +		local_bh_enable();
> +	}
> +}
>   
>   static void vdpasim_net_work(struct work_struct *work)
>   {
> @@ -42,6 +118,9 @@ static void vdpasim_net_work(struct work_struct *work)
>   
>   	spin_lock(&vdpasim->lock);
>   
> +	/* process ctrl vq first */
> +	vdpasim_net_handle_cvq(vdpasim);
> +
>   	if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
>   		goto out;
>