virtio_ring: split vring_virtqueue

Separate the two inline structures(split and packed) from the structure
vring_virtqueue.

In this way, we can use these two structures later to pass parameters
and retain temporary variables.
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-6-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_ring.c

@@ -85,46 +85,7 @@ struct vring_desc_extra {
 	u16 next;			/* The next desc state in a list. */
 };
 
-struct vring_virtqueue {
-	struct virtqueue vq;
-
-	/* Is this a packed ring? */
-	bool packed_ring;
-
-	/* Is DMA API used? */
-	bool use_dma_api;
-
-	/* Can we use weak barriers? */
-	bool weak_barriers;
-
-	/* Other side has made a mess, don't try any more. */
-	bool broken;
-
-	/* Host supports indirect buffers */
-	bool indirect;
-
-	/* Host publishes avail event idx */
-	bool event;
-
-	/* Head of free buffer list. */
-	unsigned int free_head;
-	/* Number we've added since last sync. */
-	unsigned int num_added;
-
-	/* Last used index  we've seen.
-	 * for split ring, it just contains last used index
-	 * for packed ring:
-	 * bits up to VRING_PACKED_EVENT_F_WRAP_CTR include the last used index.
-	 * bits from VRING_PACKED_EVENT_F_WRAP_CTR include the used wrap counter.
-	 */
-	u16 last_used_idx;
-
-	/* Hint for event idx: already triggered no need to disable. */
-	bool event_triggered;
-
-	union {
-		/* Available for split ring */
-		struct {
+struct vring_virtqueue_split {
 	/* Actual memory layout for this queue. */
 	struct vring vring;
 
@@ -144,10 +105,9 @@ struct vring_virtqueue {
 	/* DMA address and size information */
 	dma_addr_t queue_dma_addr;
 	size_t queue_size_in_bytes;
-		} split;
+};
 
-		/* Available for packed ring */
-		struct {
+struct vring_virtqueue_packed {
 	/* Actual memory layout for this queue. */
 	struct {
 		unsigned int num;
@@ -181,7 +141,51 @@ struct vring_virtqueue {
 	dma_addr_t device_event_dma_addr;
 	size_t ring_size_in_bytes;
 	size_t event_size_in_bytes;
-		} packed;
+};
+
+struct vring_virtqueue {
+	struct virtqueue vq;
+
+	/* Is this a packed ring? */
+	bool packed_ring;
+
+	/* Is DMA API used? */
+	bool use_dma_api;
+
+	/* Can we use weak barriers? */
+	bool weak_barriers;
+
+	/* Other side has made a mess, don't try any more. */
+	bool broken;
+
+	/* Host supports indirect buffers */
+	bool indirect;
+
+	/* Host publishes avail event idx */
+	bool event;
+
+	/* Head of free buffer list. */
+	unsigned int free_head;
+	/* Number we've added since last sync. */
+	unsigned int num_added;
+
+	/* Last used index  we've seen.
+	 * for split ring, it just contains last used index
+	 * for packed ring:
+	 * bits up to VRING_PACKED_EVENT_F_WRAP_CTR include the last used index.
+	 * bits from VRING_PACKED_EVENT_F_WRAP_CTR include the used wrap counter.
+	 */
+	u16 last_used_idx;
+
+	/* Hint for event idx: already triggered no need to disable. */
+	bool event_triggered;
+
+	union {
+		/* Available for split ring */
+		struct vring_virtqueue_split split;
+
+		/* Available for packed ring */
+		struct vring_virtqueue_packed packed;
 	};
 
 	/* How to notify other side. FIXME: commonalize hcalls! */