virtio_pci: extract the logic of active vq for modern pci

Introduce vp_active_vq() to configure vring to backend after vq attach
vring. And configure vq vector if necessary.
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-32-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_pci_modern.c

@@ -176,6 +176,29 @@ static void vp_reset(struct virtio_device *vdev)
 	vp_synchronize_vectors(vdev);
 }
 
+static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+	unsigned long index;
+
+	index = vq->index;
+
+	/* activate the queue */
+	vp_modern_set_queue_size(mdev, index, virtqueue_get_vring_size(vq));
+	vp_modern_queue_address(mdev, index, virtqueue_get_desc_addr(vq),
+				virtqueue_get_avail_addr(vq),
+				virtqueue_get_used_addr(vq));
+
+	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
+		msix_vec = vp_modern_queue_vector(mdev, index, msix_vec);
+		if (msix_vec == VIRTIO_MSI_NO_VECTOR)
+			return -EBUSY;
+	}
+
+	return 0;
+}
+
 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
 {
 	return vp_modern_config_vector(&vp_dev->mdev, vector);
@@ -220,32 +243,19 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
 
 	vq->num_max = num;
 
-	/* activate the queue */
-	vp_modern_set_queue_size(mdev, index, virtqueue_get_vring_size(vq));
-	vp_modern_queue_address(mdev, index, virtqueue_get_desc_addr(vq),
-				virtqueue_get_avail_addr(vq),
-				virtqueue_get_used_addr(vq));
+	err = vp_active_vq(vq, msix_vec);
+	if (err)
+		goto err;
 
 	vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index, NULL);
 	if (!vq->priv) {
 		err = -ENOMEM;
-		goto err_map_notify;
-	}
-
-	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
-		msix_vec = vp_modern_queue_vector(mdev, index, msix_vec);
-		if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
-			err = -EBUSY;
-			goto err_assign_vector;
-		}
+		goto err;
 	}
 
 	return vq;
 
-err_assign_vector:
-	if (!mdev->notify_base)
-		pci_iounmap(mdev->pci_dev, (void __iomem __force *)vq->priv);
-err_map_notify:
+err:
 	vring_del_virtqueue(vq);
 	return ERR_PTR(err);
 }