On Tue, Sep 27, 2022 at 11:09 AM Zhu Lingshan <lingshan.zhu@xxxxxxxxx> wrote:
>
> This commit reports driver features to user space
> only after FEATURES_OK is features negotiation is done.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
> ---
> drivers/vdpa/vdpa.c | 22 ++++++++++++++++------
> 1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 2035700d6fc8..e7765953307f 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -816,7 +816,7 @@ 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_device, features_driver;
> + u64 features_device;
> u16 val_u16;
>
> vdev->config->get_config(vdev, 0, &config, sizeof(config));
> @@ -833,11 +833,6 @@ 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_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);
>
> if (nla_put_u64_64bit(msg, VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, features_device,
> @@ -851,6 +846,8 @@ static int
> vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
> int flags, struct netlink_ext_ack *extack)
> {
> + u64 features_driver;
> + u8 status = 0;
> u32 device_id;
> void *hdr;
> int err;
> @@ -874,6 +871,19 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid,
> goto msg_err;
> }
>
> + /* only read driver features after the feature negotiation is done */
> + if (vdev->config->get_status)
> + status = vdev->config->get_status(vdev);
get_status is mandatory, so I think we can remove this check.
Or if you want a strict check on the config operations, we need to do
that in __vdpa_alloc_device().
Thanks
> +
> + if (status & VIRTIO_CONFIG_S_FEATURES_OK) {
> + features_driver = vdev->config->get_driver_features(vdev);
> + if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver,
> + VDPA_ATTR_PAD)) {
> + err = -EMSGSIZE;
> + goto msg_err;
> + }
> + }
> +
> switch (device_id) {
> case VIRTIO_ID_NET:
> err = vdpa_dev_net_config_fill(vdev, msg);
> --
> 2.31.1
>
