examples/vhost_blk: check features before inflight API

Avoid calling rte_vhost_get_vhost_ring_inflight() and
rte_vhost_get_vring_base_from_inflight() when
VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD is not set.

Signed-off-by: Keiichi Watanabe <keiichiw@chromium.org>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/examples/vhost_blk/vhost_blk.c b/examples/vhost_blk/vhost_blk.c
index 7ea6086..5c64071 100644 (file)
--- a/examples/vhost_blk/vhost_blk.c
+++ b/examples/vhost_blk/vhost_blk.c
@@ -603,10 +603,10 @@ new_device(int vid)
        struct vhost_blk_ctrlr *ctrlr;
        struct vhost_blk_queue *vq;
        char path[PATH_MAX];
-       uint64_t features;
+       uint64_t features, protocol_features;
        pthread_t tid;
        int i, ret;
-       bool packed_ring;
+       bool packed_ring, inflight_shmfd;
 
        ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
        if (ret) {
@@ -631,6 +631,16 @@ new_device(int vid)
        }
        packed_ring = !!(features & (1ULL << VIRTIO_F_RING_PACKED));
 
+       ret = rte_vhost_get_negotiated_protocol_features(
+               vid, &protocol_features);
+       if (ret) {
+               fprintf(stderr,
+                       "Failed to get the negotiated protocol features\n");
+               return -1;
+       }
+       inflight_shmfd = !!(features &
+                           (1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD));
+
        /* Disable Notifications and init last idx */
        for (i = 0; i < NUM_OF_BLK_QUEUES; i++) {
                vq = &ctrlr->queues[i];
@@ -641,10 +651,13 @@ new_device(int vid)
                assert(rte_vhost_get_vring_base(ctrlr->vid, i,
                                               &vq->last_avail_idx,
                                               &vq->last_used_idx) == 0);
-               assert(rte_vhost_get_vhost_ring_inflight(ctrlr->vid, i,
-                                               &vq->inflight_ring) == 0);
 
-               if (packed_ring) {
+               if (inflight_shmfd)
+                       assert(rte_vhost_get_vhost_ring_inflight(
+                                      ctrlr->vid, i,
+                                      &vq->inflight_ring) == 0);
+
+               if (packed_ring && inflight_shmfd) {
                        /* for the reconnection */
                        assert(rte_vhost_get_vring_base_from_inflight(
                                ctrlr->vid, i,