vhost-vdpa: open device fd in net_init_vhost_vdpa()

This patch switches to open device fd in net_init_vhost_vpda(). This is
used to prepare for the multiqueue support.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211020045600.16082-2-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

net/vhost-vdpa.c

@@ -170,24 +170,19 @@ static NetClientInfo net_vhost_vdpa_info = {
 };
 
 static int net_vhost_vdpa_init(NetClientState *peer, const char *device,
-                               const char *name, const char *vhostdev)
+                               const char *name, int vdpa_device_fd)
 {
     NetClientState *nc = NULL;
     VhostVDPAState *s;
-    int vdpa_device_fd = -1;
     int ret = 0;
     assert(name);
     nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device, name);
     snprintf(nc->info_str, sizeof(nc->info_str), TYPE_VHOST_VDPA);
     s = DO_UPCAST(VhostVDPAState, nc, nc);
-    vdpa_device_fd = qemu_open_old(vhostdev, O_RDWR);
-    if (vdpa_device_fd == -1) {
-        return -errno;
-    }
+
     s->vhost_vdpa.device_fd = vdpa_device_fd;
     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa);
     if (ret) {
-        qemu_close(vdpa_device_fd);
         qemu_del_net_client(nc);
     }
     return ret;
@@ -197,8 +192,20 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
                         NetClientState *peer, Error **errp)
 {
     const NetdevVhostVDPAOptions *opts;
+    int vdpa_device_fd, ret;
 
     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
     opts = &netdev->u.vhost_vdpa;
-    return net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, opts->vhostdev);
+
+    vdpa_device_fd = qemu_open_old(opts->vhostdev, O_RDWR);
+    if (vdpa_device_fd == -1) {
+        return -errno;
+    }
+
+    ret = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, vdpa_device_fd);
+    if (ret) {
+        qemu_close(vdpa_device_fd);
+    }
+
+    return ret;
 }