[PATCH v3 4/4] vdpa: fix improper error message when adding vdpa dev

Si-Wei Liu
2022-10-21T23:50:15Z

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.
kernel answers: Operation not supported

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

Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
---
drivers/vdpa/vdpa.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index bfb8f54..2638565 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -629,13 +629,20 @@ 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) {
+ if (config.mask && (config.mask & mdev->config_attr_mask) == 0) {
NL_SET_ERR_MSG_MOD(info->extack,
"All provided attributes are not supported");
err = -EOPNOTSUPP;
goto err;
}

+ if ((config.mask & mdev->config_attr_mask) != config.mask) {
+ NL_SET_ERR_MSG_MOD(info->extack,
+ "Some provided attributes are not supported");
+ err = -EOPNOTSUPP;
+ goto err;
+ }
+
err = mdev->ops->dev_add(mdev, name, &config);
err:
up_write(&vdpa_dev_lock);
--
1.8.3.1