From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: Mon, 1 Aug 2022 06:38:34 +0000 (+0800)
Subject: virtio_ring: split: introduce virtqueue_reinit_split()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e5175b419a1394e77ff418dd9bfaf15555dfe594;p=linux.git

virtio_ring: split: introduce virtqueue_reinit_split()

Introduce a function to initialize vq without allocating new ring,
desc_state, desc_extra.

Subsequent patches will call this function after reset vq to
reinitialize vq.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-15-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index d0df887c3adac..948f8da7b7806 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -957,6 +957,29 @@ static void virtqueue_vring_init_split(struct vring_virtqueue_split *vring_split
 	}
 }
 
+static void virtqueue_reinit_split(struct vring_virtqueue *vq)
+{
+	int num;
+
+	num = vq->split.vring.num;
+
+	vq->split.vring.avail->flags = 0;
+	vq->split.vring.avail->idx = 0;
+
+	/* reset avail event */
+	vq->split.vring.avail->ring[num] = 0;
+
+	vq->split.vring.used->flags = 0;
+	vq->split.vring.used->idx = 0;
+
+	/* reset used event */
+	*(__virtio16 *)&(vq->split.vring.used->ring[num]) = 0;
+
+	virtqueue_init(vq, num);
+
+	virtqueue_vring_init_split(&vq->split, vq);
+}
+
 static void virtqueue_vring_attach_split(struct vring_virtqueue *vq,
 					 struct vring_virtqueue_split *vring_split)
 {