> From: Zhu, Lingshan <lingshan.zhu@xxxxxxxxx>
> Sent: Monday, August 15, 2022 9:49 PM
>
> On 8/16/2022 2:15 AM, Si-Wei Liu wrote:
> >
> >
> > On 8/15/2022 2:26 AM, Zhu Lingshan wrote:
> >> This commit adds a new vDPA netlink attribution
> >> VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES. Userspace can query
> features
> >> of vDPA devices through this new attr.
> >>
> >> Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
> >> ---
> >> drivers/vdpa/vdpa.c | 17 +++++++++++++----
> >> include/uapi/linux/vdpa.h | 3 +++
> >> 2 files changed, 16 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index
> >> c06c02704461..efb55a06e961 100644
> >> --- a/drivers/vdpa/vdpa.c
> >> +++ b/drivers/vdpa/vdpa.c
> >> @@ -491,6 +491,8 @@ static int vdpa_mgmtdev_fill(const struct
> >> vdpa_mgmt_dev *mdev, struct sk_buff *m
> >> err = -EMSGSIZE;
> >> goto msg_err;
> >> }
> >> +
> >> + /* report features of a vDPA management device through
> >> VDPA_ATTR_DEV_SUPPORTED_FEATURES */
> >> if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES,
> >> mdev->supported_features, VDPA_ATTR_PAD)) {
> >> err = -EMSGSIZE;
> >> @@ -815,7 +817,7 @@ static int vdpa_dev_net_mq_config_fill(struct
> >> vdpa_device *vdev,
> >> static int vdpa_dev_net_config_fill(struct vdpa_device *vdev,
> >> struct sk_buff *msg)
> >> {
> >> struct virtio_net_config config = {};
> >> - u64 features;
> >> + u64 features_device, features_driver;
> >> u16 val_u16;
> >> vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config));
> >> @@ -832,12 +834,19 @@ static int vdpa_dev_net_config_fill(struct
> >> vdpa_device *vdev, struct sk_buff *ms
> >> if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))
> >> return -EMSGSIZE;
> >> - features = vdev->config->get_driver_features(vdev);
> >> - if (nla_put_u64_64bit(msg,
> VDPA_ATTR_DEV_NEGOTIATED_FEATURES,
> >> features,
> >> + features_driver = vdev->config->get_driver_features(vdev);
> >> + if (nla_put_u64_64bit(msg,
> VDPA_ATTR_DEV_NEGOTIATED_FEATURES,
> >> features_driver,
> >> + VDPA_ATTR_PAD))
> >> + return -EMSGSIZE;
> >> +
> >> + features_device = vdev->config->get_device_features(vdev);
> >> +
> >> + /* report features of a vDPA device through
> >> VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES */
> >> + if (nla_put_u64_64bit(msg,
> >> VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, features_device,
> >> VDPA_ATTR_PAD))
> >> return -EMSGSIZE;
> >> - return vdpa_dev_net_mq_config_fill(vdev, msg, features,
> >> &config);
> >> + return vdpa_dev_net_mq_config_fill(vdev, msg, features_driver,
> >> &config);
> >> }
> >> static int
> >> diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
> >> index 25c55cab3d7c..d171b92ef522 100644
> >> --- a/include/uapi/linux/vdpa.h
> >> +++ b/include/uapi/linux/vdpa.h
> >> @@ -46,7 +46,10 @@ enum vdpa_attr {
> >> VDPA_ATTR_DEV_NEGOTIATED_FEATURES, /* u64 */
> >> VDPA_ATTR_DEV_MGMTDEV_MAX_VQS, /* u32 */
> >> + /* features of a vDPA management device */
Say comment as.
/* Features of the vDPA management device matching the virtio feature bits 0 to 63 when queried on the mgmt. device.
* When returned on the vdpa device, it indicates virtio feature bits 0 to 63 of the vdpa device
*/
> >> VDPA_ATTR_DEV_SUPPORTED_FEATURES, /* u64 */
> >> + /* features of a vDPA device, e.g., /dev/vhost-vdpa0 */
> >> + VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, /* u64 */
> > Append to the end, please. Otherwise it breaks userspace ABI.
> OK, will fix it in V2
I have read Se-Wei comment in the v4.
However I disagree, we don’t need to continue the past mistake done with the naming.
Please add a comment that VDPA_ATTR_DEV_SUPPORTED_FEATURES like above about the exception.
We established that there is no race condition either.
So no need to add new UAPI for some past history.
