[PATCH 1/2] vhost-vdpa: define and use default value for vhostdev

[Laurent Vivier <lvivier@redhat.com>]

vhostdev is defined as optional in net.json, and if not set
/dev/vhost-vdpa-0 should be used.

The default value is not set and if vhostdev is not provided
QEMU crashes with a SIGSEGV exception.

Fixes: 1e0a84ea49b6 ("vhost-vdpa: introduce vhost-vdpa net client")
Cc: lulu@redhat.com
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 net/vhost-vdpa.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index bc0e0d2d35b7..24103ef241e4 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -24,6 +24,9 @@
 #include "monitor/monitor.h"
 #include "hw/virtio/vhost.h"
 
+/* default vhostdev as defined in qapi/net.json */
+#define VHOST_VDPA_DEFAULT_VHOSTDEV "/dev/vhost-vdpa-0"
+
 /* Todo:need to add the multiqueue support here */
 typedef struct VhostVDPAState {
     NetClientState nc;
@@ -224,5 +227,7 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
                           (char *)name, errp)) {
         return -1;
     }
-    return net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, opts->vhostdev);
+    return net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
+                               opts->has_vhostdev ?
+                               opts->vhostdev : VHOST_VDPA_DEFAULT_VHOSTDEV);
 }
-- 
2.26.2