vhost: Pass device path to vhost_dev_init()

The path to /dev/vhost-net is currently hardcoded in vhost_dev_init().
This needs to be changed so that /dev/vhost-scsi can be used.  Pass in
the device path instead of hardcoding it.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/vhost.c

@@ -747,14 +747,15 @@ static void vhost_eventfd_del(MemoryListener *listener,
 {
 }
 
-int vhost_dev_init(struct vhost_dev *hdev, int devfd, bool force)
+int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
+                   bool force)
 {
     uint64_t features;
     int r;
     if (devfd >= 0) {
         hdev->control = devfd;
     } else {
-        hdev->control = open("/dev/vhost-net", O_RDWR);
+        hdev->control = open(devpath, O_RDWR);
         if (hdev->control < 0) {
             return -errno;
         }

hw/vhost.h

@@ -44,7 +44,8 @@ struct vhost_dev {
     bool force;
 };
 
-int vhost_dev_init(struct vhost_dev *hdev, int devfd, bool force);
+int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
+                   bool force);
 void vhost_dev_cleanup(struct vhost_dev *hdev);
 bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev);
 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);

hw/vhost_net.c

@@ -109,7 +109,7 @@ struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
         (1 << VHOST_NET_F_VIRTIO_NET_HDR);
     net->backend = r;
 
-    r = vhost_dev_init(&net->dev, devfd, force);
+    r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net", force);
     if (r < 0) {
         goto fail;
     }