vhost: relax full barriers for used idx

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

diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c
index ef21ca2..99a926a 100644 (file)
--- a/lib/librte_vhost/vdpa.c
+++ b/lib/librte_vhost/vdpa.c
@@ -77,6 +77,16 @@ rte_vdpa_register_device(struct rte_device *rte_dev,
        if (ops == NULL)
                return NULL;
 
+       /* Check mandatory ops are implemented */
+       if (!ops->get_queue_num || !ops->get_features ||
+                       !ops->get_protocol_features || !ops->dev_conf ||
+                       !ops->dev_close || !ops->set_vring_state ||
+                       !ops->set_features) {
+               VHOST_LOG_CONFIG(ERR,
+                               "Some mandatory vDPA ops aren't implemented\n");
+               return NULL;
+       }
+
        rte_spinlock_lock(&vdpa_device_list_lock);
        /* Check the device hasn't been register already */
        dev = __vdpa_find_device_by_name(rte_dev->name);
@@ -207,8 +217,8 @@ rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
                idx++;
        }
 
-       rte_smp_wmb();
-       vq->used->idx = idx_m;
+       /* used idx is the synchronization point for the split vring */
+       __atomic_store_n(&vq->used->idx, idx_m, __ATOMIC_RELEASE);
 
        if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))
                vring_used_event(s_vring) = idx_m;