+/*
+ * Allocate a queue pair if it hasn't been allocated yet
+ */
+static int
+vhost_user_check_and_alloc_queue_pair(struct virtio_net *dev, VhostUserMsg *msg)
+{
+ uint16_t vring_idx;
+
+ switch (msg->request) {
+ case VHOST_USER_SET_VRING_KICK:
+ case VHOST_USER_SET_VRING_CALL:
+ case VHOST_USER_SET_VRING_ERR:
+ vring_idx = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
+ break;
+ case VHOST_USER_SET_VRING_NUM:
+ case VHOST_USER_SET_VRING_BASE:
+ case VHOST_USER_SET_VRING_ENABLE:
+ vring_idx = msg->payload.state.index;
+ break;
+ case VHOST_USER_SET_VRING_ADDR:
+ vring_idx = msg->payload.addr.index;
+ break;
+ default:
+ return 0;
+ }
+
+ if (vring_idx >= VHOST_MAX_VRING) {
+ RTE_LOG(ERR, VHOST_CONFIG,
+ "invalid vring index: %u\n", vring_idx);
+ return -1;
+ }
+
+ if (dev->virtqueue[vring_idx])
+ return 0;
+
+ return alloc_vring_queue(dev, vring_idx);
+}
+