vdpa: fix improper error message when adding vdpa dev

In below example, before the fix, mtu attribute is supported
by the parent mgmtdev, but the error message showing "All
provided are not supported" is just misleading.

$ vdpa mgmtdev show
vdpasim_net:
  supported_classes net
  max_supported_vqs 3
  dev_features MTU MAC CTRL_VQ CTRL_MAC_ADDR ANY_LAYOUT VERSION_1 ACCESS_PLATFORM

$ vdpa dev add mgmtdev vdpasim_net name vdpasim0 mtu 5000 max_vqp 2
Error: vdpa: All provided attributes are not supported.
kernel answers: Operation not supported

After fix, the relevant error message will be like:

$ vdpa dev add mgmtdev vdpasim_net name vdpasim0 mtu 5000 max_vqp 2
Error: vdpa: Some provided attributes are not supported: 0x1000.
kernel answers: Operation not supported

Fixes: d8ca2fa5be1b ("vdpa: Enable user to set mac and mtu of vdpa device")
Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Message-Id: <1675725124-7375-2-git-send-email-si-wei.liu@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index a1bb5b92212deddec84e5e73bb81644511d29a83..e71898ec5ce7d272ad4cb9bafb19b5ae9a14d130 100644 (file)
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -627,9 +627,11 @@ static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *i
                err = PTR_ERR(mdev);
                goto err;
        }
+
        if ((config.mask & mdev->config_attr_mask) != config.mask) {
-               NL_SET_ERR_MSG_MOD(info->extack,
-                                  "All provided attributes are not supported");
+               NL_SET_ERR_MSG_FMT_MOD(info->extack,
+                                      "Some provided attributes are not supported: 0x%llx",
+                                      config.mask & ~mdev->config_attr_mask);
                err = -EOPNOTSUPP;
                goto err;
        }