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Subject: Re: [PATCH v2 13/17] vdpa_sim: set vringh notify callback
To:     Stefano Garzarella <sgarzare@redhat.com>,
        virtualization@lists.linux-foundation.org
Cc:     Stefan Hajnoczi <stefanha@redhat.com>,
        linux-kernel@vger.kernel.org, Laurent Vivier <lvivier@redhat.com>,
        Max Gurtovoy <mgurtovoy@nvidia.com>,
        "Michael S. Tsirkin" <mst@redhat.com>, Eli Cohen <elic@nvidia.com>
References: <20201126144950.92850-1-sgarzare@redhat.com>
 <20201126144950.92850-14-sgarzare@redhat.com>
From:   Jason Wang <jasowang@redhat.com>
Message-ID: <5569e198-22be-514a-744a-1bef9a3b95ce@redhat.com>
Date:   Mon, 30 Nov 2020 11:27:51 +0800
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On 2020/11/26 下午10:49, Stefano Garzarella wrote:
> Instead of calling the vq callback directly, we can leverage the
> vringh_notify() function, adding vdpasim_vq_notify() and setting it
> in the vringh notify callback.
>
> Suggested-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
>   drivers/vdpa/vdpa_sim/vdpa_sim.c | 21 +++++++++++++++++----
>   1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 8b87ce0485b6..4327efd6d41e 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -120,6 +120,17 @@ static struct vdpasim *dev_to_sim(struct device *dev)
>   	return vdpa_to_sim(vdpa);
>   }
>   
> +static void vdpasim_vq_notify(struct vringh *vring)
> +{
> +	struct vdpasim_virtqueue *vq =
> +		container_of(vring, struct vdpasim_virtqueue, vring);
> +
> +	if (!vq->cb)
> +		return;
> +
> +	vq->cb(vq->private);
> +}
> +
>   static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
>   {
>   	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> @@ -131,6 +142,8 @@ static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
>   			  (uintptr_t)vq->driver_addr,
>   			  (struct vring_used *)
>   			  (uintptr_t)vq->device_addr);
> +
> +	vq->vring.notify = vdpasim_vq_notify;


Do we need to clear notify during reset?

Other looks good.


>   }
>   
>   static void vdpasim_vq_reset(struct vdpasim *vdpasim,
> @@ -220,10 +233,10 @@ static void vdpasim_net_work(struct work_struct *work)
>   		smp_wmb();
>   
>   		local_bh_disable();
> -		if (txq->cb)
> -			txq->cb(txq->private);
> -		if (rxq->cb)
> -			rxq->cb(rxq->private);
> +		if (vringh_need_notify_iotlb(&txq->vring) > 0)
> +			vringh_notify(&txq->vring);
> +		if (vringh_need_notify_iotlb(&rxq->vring) > 0)
> +			vringh_notify(&rxq->vring);
>   		local_bh_enable();
>   
>   		if (++pkts > 4) {