dma: use ERROR_INT()

The first in a series excising the use of the "return -errno" idiom. This is a
non-standard usage, and in userspace, we have "errno" for delivering side-band
error values. As there have been multiple bugs from not using standard error
return methods like -1+errno or NULL+errno, let's do that.

Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Thanos Makatos <thanos.makatos@nutanix.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/libvfio-user.h b/include/libvfio-user.h
index a43f38a..f2876a1 100644
--- a/include/libvfio-user.h
+++ b/include/libvfio-user.h
@@ -404,9 +404,9 @@ typedef void (vfu_dma_register_cb_t)(vfu_ctx_t *vfu_ctx, vfu_dma_info_t *info);
  * This is required if you want to be able to access guest memory directly via
  * a mapping.
  *
- * The callback should return 0 on success, errno on failure (although
- * unregister should not fail: this will not stop a guest from unregistering the
- * region).
+ * The callback should return 0 on success, -1 with errno set on failure
+ * (although unregister should not fail: this will not stop a guest from
+ * unregistering the region).
  *
  * @vfu_ctx: the libvfio-user context
  * @info: the DMA info