virtio: introduce __virtio_queue_reset()

Separate the logic of vq reset. This logic will be called directly
later.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-2-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/virtio/virtio.c

@@ -2464,6 +2464,26 @@ static enum virtio_device_endian virtio_current_cpu_endian(void)
     }
 }
 
+static void __virtio_queue_reset(VirtIODevice *vdev, uint32_t i)
+{
+    vdev->vq[i].vring.desc = 0;
+    vdev->vq[i].vring.avail = 0;
+    vdev->vq[i].vring.used = 0;
+    vdev->vq[i].last_avail_idx = 0;
+    vdev->vq[i].shadow_avail_idx = 0;
+    vdev->vq[i].used_idx = 0;
+    vdev->vq[i].last_avail_wrap_counter = true;
+    vdev->vq[i].shadow_avail_wrap_counter = true;
+    vdev->vq[i].used_wrap_counter = true;
+    virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR);
+    vdev->vq[i].signalled_used = 0;
+    vdev->vq[i].signalled_used_valid = false;
+    vdev->vq[i].notification = true;
+    vdev->vq[i].vring.num = vdev->vq[i].vring.num_default;
+    vdev->vq[i].inuse = 0;
+    virtio_virtqueue_reset_region_cache(&vdev->vq[i]);
+}
+
 void virtio_reset(void *opaque)
 {
     VirtIODevice *vdev = opaque;
@@ -2495,22 +2515,7 @@ void virtio_reset(void *opaque)
     virtio_notify_vector(vdev, vdev->config_vector);
 
     for(i = 0; i < VIRTIO_QUEUE_MAX; i++) {
-        vdev->vq[i].vring.desc = 0;
-        vdev->vq[i].vring.avail = 0;
-        vdev->vq[i].vring.used = 0;
-        vdev->vq[i].last_avail_idx = 0;
-        vdev->vq[i].shadow_avail_idx = 0;
-        vdev->vq[i].used_idx = 0;
-        vdev->vq[i].last_avail_wrap_counter = true;
-        vdev->vq[i].shadow_avail_wrap_counter = true;
-        vdev->vq[i].used_wrap_counter = true;
-        virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR);
-        vdev->vq[i].signalled_used = 0;
-        vdev->vq[i].signalled_used_valid = false;
-        vdev->vq[i].notification = true;
-        vdev->vq[i].vring.num = vdev->vq[i].vring.num_default;
-        vdev->vq[i].inuse = 0;
-        virtio_virtqueue_reset_region_cache(&vdev->vq[i]);
+        __virtio_queue_reset(vdev, i);
     }
 }