Re: [PATCH v9 08/32] virtio_ring: split: extract the logic of attach vring

From: Jason Wang <jasowang@redhat.com>
To: Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
	virtualization@lists.linux-foundation.org
Cc: Jeff Dike <jdike@addtoit.com>,
	Richard Weinberger <richard@nod.at>,
	Anton Ivanov <anton.ivanov@cambridgegreys.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Hans de Goede <hdegoede@redhat.com>,
	Mark Gross <markgross@kernel.org>,
	Vadim Pasternak <vadimp@nvidia.com>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Cornelia Huck <cohuck@redhat.com>,
	Halil Pasic <pasic@linux.ibm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
	Sven Schnelle <svens@linux.ibm.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	John Fastabend <john.fastabend@gmail.com>,
	Johannes Berg <johannes.berg@intel.com>,
	Vincent Whitchurch <vincent.whitchurch@axis.com>,
	linux-um@lists.infradead.org, netdev@vger.kernel.org,
	platform-driver-x86@vger.kernel.org,
	linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org,
	kvm@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH v9 08/32] virtio_ring: split: extract the logic of attach vring
Date: Tue, 12 Apr 2022 11:31:08 +0800	[thread overview]
Message-ID: <28237db0-cf04-aa36-b7b8-de55b11d18db@redhat.com> (raw)
In-Reply-To: <20220406034346.74409-9-xuanzhuo@linux.alibaba.com>

在 2022/4/6 上午11:43, Xuan Zhuo 写道:
> Separate the logic of attach vring, subsequent patches will call it
> separately.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>   drivers/virtio/virtio_ring.c | 20 ++++++++++++++------
>   1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 6de67439cb57..083f2992ba0d 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -916,6 +916,19 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
>   	return NULL;
>   }
>   
> +static void vring_virtqueue_attach_split(struct vring_virtqueue *vq,
> +					 struct vring vring,
> +					 struct vring_desc_state_split *desc_state,
> +					 struct vring_desc_extra *desc_extra)
> +{
> +	vq->split.vring = vring;
> +	vq->split.queue_dma_addr = 0;
> +	vq->split.queue_size_in_bytes = 0;

Any reason to add the above two assignment in attach? It seems belong to 
free or reset.

Thanks

> +
> +	vq->split.desc_state = desc_state;
> +	vq->split.desc_extra = desc_extra;
> +}
> +
>   static int vring_alloc_state_extra_split(u32 num,
>   					 struct vring_desc_state_split **desc_state,
>   					 struct vring_desc_extra **desc_extra)
> @@ -2262,10 +2275,6 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
>   		vq->weak_barriers = false;
>   
> -	vq->split.queue_dma_addr = 0;
> -	vq->split.queue_size_in_bytes = 0;
> -
> -	vq->split.vring = vring;
>   	vq->split.avail_flags_shadow = 0;
>   	vq->split.avail_idx_shadow = 0;
>   
> @@ -2283,8 +2292,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   		return NULL;
>   	}
>   
> -	vq->split.desc_state = state;
> -	vq->split.desc_extra = extra;
> +	vring_virtqueue_attach_split(vq, vring, state, extra);
>   
>   	/* Put everything in free lists. */
>   	vq->free_head = 0;