rdma: Fix qemu crash when IPv6 address is used for migration

Qemu crashes when IPv6 address is specified for migration and access
to any RDMA uverbs device available on the system is blocked using cgroups.
Fix the crash by checking the return value of ibv_open_device routine.

Signed-off-by: Meghana Cheripady <meghana.cheripady@avagotech.com>
Signed-off-by: Padmanabh Ratnakar <padmanabh.ratnakar@avagotech.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/migration/rdma.c b/migration/rdma.c
index 77e34441dc..36719038f7 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -790,6 +790,13 @@ static int qemu_rdma_broken_ipv6_kernel(Error **errp, struct ibv_context *verbs)
 
         for (x = 0; x < num_devices; x++) {
             verbs = ibv_open_device(dev_list[x]);
+            if (!verbs) {
+                if (errno == EPERM) {
+                    continue;
+                } else {
+                    return -EINVAL;
+                }
+            }
 
             if (ibv_query_port(verbs, 1, &port_attr)) {
                 ibv_close_device(verbs);