Re: [PATCH v2 16/17] vdpa_sim: split vdpasim_virtqueue's iov field in out_iov and in_iov

[Jason Wang <jasowang@redhat.com>]

On 2020/11/26 下午10:49, Stefano Garzarella wrote:
> vringh_getdesc_iotlb() manages 2 iovs for writable and readable
> descriptors. This is very useful for the block device, where for
> each request we have both types of descriptor.
>
> Let's split the vdpasim_virtqueue's iov field in out_iov and
> in_iov to use them with vringh_getdesc_iotlb().
>
> We are using VIRTIO terminology for "out" (readable by the device)
> and "in" (writable by the device) descriptors.
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> v2:
> - used VIRTIO terminology [Stefan]
> ---


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


>   drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++++-----
>   1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index f5f41f20ee0b..f8ee261ef4ae 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -33,7 +33,8 @@ u8 macaddr_buf[ETH_ALEN];
>   
>   struct vdpasim_virtqueue {
>   	struct vringh vring;
> -	struct vringh_kiov iov;
> +	struct vringh_kiov in_iov;
> +	struct vringh_kiov out_iov;
>   	unsigned short head;
>   	bool ready;
>   	u64 desc_addr;
> @@ -197,12 +198,12 @@ static void vdpasim_net_work(struct work_struct *work)
>   
>   	while (true) {
>   		total_write = 0;
> -		err = vringh_getdesc_iotlb(&txq->vring, &txq->iov, NULL,
> +		err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
>   					   &txq->head, GFP_ATOMIC);
>   		if (err <= 0)
>   			break;
>   
> -		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->iov,
> +		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
>   					   &rxq->head, GFP_ATOMIC);
>   		if (err <= 0) {
>   			vringh_complete_iotlb(&txq->vring, txq->head, 0);
> @@ -210,13 +211,13 @@ static void vdpasim_net_work(struct work_struct *work)
>   		}
>   
>   		while (true) {
> -			read = vringh_iov_pull_iotlb(&txq->vring, &txq->iov,
> +			read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
>   						     vdpasim->buffer,
>   						     PAGE_SIZE);
>   			if (read <= 0)
>   				break;
>   
> -			write = vringh_iov_push_iotlb(&rxq->vring, &rxq->iov,
> +			write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
>   						      vdpasim->buffer, read);
>   			if (write <= 0)
>   				break;