Re: [PATCH v3 12/19] vdpa_sim: make 'config' generic and usable for any device type

From: Jason Wang <jasowang@redhat.com>
To: Stefano Garzarella <sgarzare@redhat.com>,
	virtualization@lists.linux-foundation.org
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Oren Duer <oren@nvidia.com>, Laurent Vivier <lvivier@redhat.com>,
	linux-kernel@vger.kernel.org, Max Gurtovoy <mgurtovoy@nvidia.com>,
	Shahaf Shuler <shahafs@nvidia.com>, Eli Cohen <elic@nvidia.com>
Subject: Re: [PATCH v3 12/19] vdpa_sim: make 'config' generic and usable for any device type
Date: Mon, 7 Dec 2020 13:22:42 +0800	[thread overview]
Message-ID: <c32b4030-fccb-3e77-faf0-a53b8a865563@redhat.com> (raw)
In-Reply-To: <20201203170511.216407-13-sgarzare@redhat.com>


On 2020/12/4 上午1:05, Stefano Garzarella wrote:
> Add new 'config_size' attribute in 'vdpasim_dev_attr' and allocates
> 'config' dynamically to support any device types.
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
>   drivers/vdpa/vdpa_sim/vdpa_sim.c | 17 +++++++++++++----
>   1 file changed, 13 insertions(+), 4 deletions(-)


Acked-by: Jason Wang <jasowang@redhat.com>


>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 949f4231d08a..fe71ed7890e1 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -62,6 +62,7 @@ struct vdpasim_virtqueue {
>   
>   struct vdpasim_dev_attr {
>   	u64 supported_features;
> +	size_t config_size;
>   	int nvqs;
>   	u32 id;
>   
> @@ -76,7 +77,8 @@ struct vdpasim {
>   	struct vdpasim_dev_attr dev_attr;
>   	/* spinlock to synchronize virtqueue state */
>   	spinlock_t lock;
> -	struct virtio_net_config config;
> +	/* virtio config according to device type */
> +	void *config;
>   	struct vhost_iotlb *iommu;
>   	void *buffer;
>   	u32 status;
> @@ -376,6 +378,10 @@ static struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
>   		goto err_iommu;
>   	set_dma_ops(dev, &vdpasim_dma_ops);
>   
> +	vdpasim->config = kzalloc(dev_attr->config_size, GFP_KERNEL);
> +	if (!vdpasim->config)
> +		goto err_iommu;
> +
>   	vdpasim->vqs = kcalloc(dev_attr->nvqs, sizeof(struct vdpasim_virtqueue),
>   			       GFP_KERNEL);
>   	if (!vdpasim->vqs)
> @@ -516,7 +522,8 @@ static u64 vdpasim_get_features(struct vdpa_device *vdpa)
>   static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
>   {
>   	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> -	struct virtio_net_config *config = &vdpasim->config;
> +	struct virtio_net_config *config =
> +		(struct virtio_net_config *)vdpasim->config;
>   
>   	/* DMA mapping must be done by driver */
>   	if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
> @@ -588,8 +595,8 @@ static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
>   {
>   	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
>   
> -	if (offset + len < sizeof(struct virtio_net_config))
> -		memcpy(buf, (u8 *)&vdpasim->config + offset, len);
> +	if (offset + len < vdpasim->dev_attr.config_size)
> +		memcpy(buf, vdpasim->config + offset, len);
>   }
>   
>   static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,
> @@ -676,6 +683,7 @@ static void vdpasim_free(struct vdpa_device *vdpa)
>   	if (vdpasim->iommu)
>   		vhost_iotlb_free(vdpasim->iommu);
>   	kfree(vdpasim->vqs);
> +	kfree(vdpasim->config);
>   }
>   
>   static const struct vdpa_config_ops vdpasim_config_ops = {
> @@ -738,6 +746,7 @@ static int __init vdpasim_dev_init(void)
>   	dev_attr.id = VIRTIO_ID_NET;
>   	dev_attr.supported_features = VDPASIM_NET_FEATURES;
>   	dev_attr.nvqs = VDPASIM_VQ_NUM;
> +	dev_attr.config_size = sizeof(struct virtio_net_config);
>   	dev_attr.work_fn = vdpasim_net_work;
>   
>   	vdpasim_dev = vdpasim_create(&dev_attr);