net/virtio: rationalize queue flushing

[dpdk.git] / lib / librte_vhost / vhost_user.c

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 0ea28ec..1dd1a61 100644 (file)
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1260,12 +1260,47 @@ vhost_user_check_and_alloc_queue_pair(struct virtio_net *dev, VhostUserMsg *msg)
        return alloc_vring_queue(dev, vring_idx);
 }
 
+static void
+vhost_user_lock_all_queue_pairs(struct virtio_net *dev)
+{
+       unsigned int i = 0;
+       unsigned int vq_num = 0;
+
+       while (vq_num < dev->nr_vring) {
+               struct vhost_virtqueue *vq = dev->virtqueue[i];
+
+               if (vq) {
+                       rte_spinlock_lock(&vq->access_lock);
+                       vq_num++;
+               }
+               i++;
+       }
+}
+
+static void
+vhost_user_unlock_all_queue_pairs(struct virtio_net *dev)
+{
+       unsigned int i = 0;
+       unsigned int vq_num = 0;
+
+       while (vq_num < dev->nr_vring) {
+               struct vhost_virtqueue *vq = dev->virtqueue[i];
+
+               if (vq) {
+                       rte_spinlock_unlock(&vq->access_lock);
+                       vq_num++;
+               }
+               i++;
+       }
+}
+
 int
 vhost_user_msg_handler(int vid, int fd)
 {
        struct virtio_net *dev;
        struct VhostUserMsg msg;
        int ret;
+       int unlock_required = 0;
 
        dev = get_device(vid);
        if (dev == NULL)
@@ -1311,6 +1346,38 @@ vhost_user_msg_handler(int vid, int fd)
                return -1;
        }
 
+       /*
+        * Note: we don't lock all queues on VHOST_USER_GET_VRING_BASE,
+        * since it is sent when virtio stops and device is destroyed.
+        * destroy_device waits for queues to be inactive, so it is safe.
+        * Otherwise taking the access_lock would cause a dead lock.
+        */
+       switch (msg.request.master) {
+       case VHOST_USER_SET_FEATURES:
+       case VHOST_USER_SET_PROTOCOL_FEATURES:
+       case VHOST_USER_SET_OWNER:
+       case VHOST_USER_RESET_OWNER:
+       case VHOST_USER_SET_MEM_TABLE:
+       case VHOST_USER_SET_LOG_BASE:
+       case VHOST_USER_SET_LOG_FD:
+       case VHOST_USER_SET_VRING_NUM:
+       case VHOST_USER_SET_VRING_ADDR:
+       case VHOST_USER_SET_VRING_BASE:
+       case VHOST_USER_SET_VRING_KICK:
+       case VHOST_USER_SET_VRING_CALL:
+       case VHOST_USER_SET_VRING_ERR:
+       case VHOST_USER_SET_VRING_ENABLE:
+       case VHOST_USER_SEND_RARP:
+       case VHOST_USER_NET_SET_MTU:
+       case VHOST_USER_SET_SLAVE_REQ_FD:
+               vhost_user_lock_all_queue_pairs(dev);
+               unlock_required = 1;
+               break;
+       default:
+               break;
+
+       }
+
        switch (msg.request.master) {
        case VHOST_USER_GET_FEATURES:
                msg.payload.u64 = vhost_user_get_features(dev);
@@ -1414,6 +1481,9 @@ vhost_user_msg_handler(int vid, int fd)
 
        }
 
+       if (unlock_required)
+               vhost_user_unlock_all_queue_pairs(dev);
+
        if (msg.flags & VHOST_USER_NEED_REPLY) {
                msg.payload.u64 = !!ret;
                msg.size = sizeof(msg.payload.u64);