From 56775e141b18790f70e05537f3a1417565e766ac Mon Sep 17 00:00:00 2001
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: Mon, 1 Aug 2022 14:38:42 +0800
Subject: [PATCH] virtio_ring: packed: introduce virtqueue_reinit_packed()
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: <20220801063902.129329-23-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
drivers/virtio/virtio_ring.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 93d2a950f5361..db06fb0ddfd60 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1957,6 +1957,18 @@ static void virtqueue_vring_attach_packed(struct vring_virtqueue *vq,
vq->free_head = 0;
}
+static void virtqueue_reinit_packed(struct vring_virtqueue *vq)
+{
+ memset(vq->packed.vring.device, 0, vq->packed.event_size_in_bytes);
+ memset(vq->packed.vring.driver, 0, vq->packed.event_size_in_bytes);
+
+ /* we need to reset the desc.flags. For more, see is_used_desc_packed() */
+ memset(vq->packed.vring.desc, 0, vq->packed.ring_size_in_bytes);
+
+ virtqueue_init(vq, vq->packed.vring.num);
+ virtqueue_vring_init_packed(&vq->packed, !!vq->vq.callback);
+}
+
static struct virtqueue *vring_create_virtqueue_packed(
unsigned int index,
unsigned int num,