vhost: Return 0/-errno in vhost_dev_init()

Instead of just returning 0/-1 and letting the caller make up a
meaningless error message, switch to 0/-errno so that different kinds of
errors can be distinguished in the caller.

This involves changing a few more callbacks in VhostOps to return
0/-errno: .vhost_set_owner(), .vhost_get_features() and
.vhost_virtqueue_set_busyloop_timeout(). The implementations of these
functions are trivial as they generally just send a message to the
backend.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210609154658.350308-4-kwolf@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index fd13135706..c7f9d8bb06 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1309,13 +1309,13 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
 
     r = hdev->vhost_ops->vhost_set_owner(hdev);
     if (r < 0) {
-        error_setg(errp, "vhost_set_owner failed");
+        error_setg_errno(errp, -r, "vhost_set_owner failed");
         goto fail;
     }
 
     r = hdev->vhost_ops->vhost_get_features(hdev, &features);
     if (r < 0) {
-        error_setg(errp, "vhost_get_features failed");
+        error_setg_errno(errp, -r, "vhost_get_features failed");
         goto fail;
     }
 
@@ -1332,7 +1332,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
             r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i,
                                                      busyloop_timeout);
             if (r < 0) {
-                error_setg(errp, "Failed to set busyloop timeout");
+                error_setg_errno(errp, -r, "Failed to set busyloop timeout");
                 goto fail_busyloop;
             }
         }
@@ -1391,7 +1391,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
     if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) {
         error_setg(errp, "vhost backend memory slots limit is less"
                    " than current number of present memory slots");
-        r = -1;
+        r = -EINVAL;
         goto fail_busyloop;
     }