Jason Wang
2022-Sep-21 07:44 UTC
[PATCH 1/4] vDPA: allow userspace to query features of a vDPA device
On Wed, Sep 21, 2022 at 2:00 PM Zhu, Lingshan <lingshan.zhu at intel.com> wrote:> > > > On 9/21/2022 10:17 AM, Jason Wang wrote: > > On Tue, Sep 20, 2022 at 5:58 PM Zhu, Lingshan <lingshan.zhu at intel.com> wrote: > >> > >> > >> On 9/20/2022 10:02 AM, Jason Wang wrote: > >>> On Fri, Sep 9, 2022 at 5:05 PM Zhu Lingshan <lingshan.zhu at intel.com> 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. > >>>> > >>>> This commit invokes vdpa_config_ops.get_config() than > >>>> vdpa_get_config_unlocked() to read the device config > >>>> spcae, so no raeces in vdpa_set_features_unlocked() > >>>> > >>>> Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com> > >>> It's better to share the userspace code as well. > >> OK, will share it in V2. > >>>> --- > >>>> drivers/vdpa/vdpa.c | 19 ++++++++++++++----- > >>>> include/uapi/linux/vdpa.h | 4 ++++ > >>>> 2 files changed, 18 insertions(+), 5 deletions(-) > >>>> > >>>> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > >>>> index c06c02704461..798a02c7aa94 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 */ > >>> The code explains itself, there's no need for the comment. > >> these comments are required in other discussions > > I think it's more than sufficient to clarify the semantic where it is defined. > OK, then only comments in the header file > > > >>>> if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES, > >>>> mdev->supported_features, VDPA_ATTR_PAD)) { > >>>> err = -EMSGSIZE; > >>>> @@ -815,10 +817,10 @@ 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)); > >>>> + vdev->config->get_config(vdev, 0, &config, sizeof(config)); > >>>> > >>>> if (nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR, sizeof(config.mac), > >>>> config.mac)) > >>>> @@ -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..97531b52dcbe 100644 > >>>> --- a/include/uapi/linux/vdpa.h > >>>> +++ b/include/uapi/linux/vdpa.h > >>>> @@ -46,12 +46,16 @@ enum vdpa_attr { > >>>> > >>>> VDPA_ATTR_DEV_NEGOTIATED_FEATURES, /* u64 */ > >>>> VDPA_ATTR_DEV_MGMTDEV_MAX_VQS, /* u32 */ > >>>> + /* features of a vDPA management device */ > >>>> VDPA_ATTR_DEV_SUPPORTED_FEATURES, /* u64 */ > >>>> > >>>> VDPA_ATTR_DEV_QUEUE_INDEX, /* u32 */ > >>>> VDPA_ATTR_DEV_VENDOR_ATTR_NAME, /* string */ > >>>> VDPA_ATTR_DEV_VENDOR_ATTR_VALUE, /* u64 */ > >>>> > >>>> + /* features of a vDPA device, e.g., /dev/vhost-vdpa0 */ > >>>> + VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, /* u64 */ > >>> What's the difference between this and VDPA_ATTR_DEV_SUPPORTED_FEATURES? > >> This is to report a vDPA device features, and > >> VDPA_ATTR_DEV_SUPPORTED_FEATURES > >> is used for reporting the management device features, we have a long > >> discussion > >> on this before. > > Yes, but the comment is not clear in many ways: > > > > " features of a vDPA management device" sounds like features that is > > out of the scope of the virtio. > I think the term "vDPA device" implies that it is a virtio device. > So how about: "virtio features of a vDPA management device"Not a native speaker, but how about "virtio features that are supported by the vDPA management device?" Thanks> > > > And > > > > "/dev/vhost-vdpa0" is not a vDPA device but a vhost-vDPA device. > will remove this example here. > > Thanks > > > > Thanks > > > >>> Thanks > >>> > >>>> + > >>>> /* new attributes must be added above here */ > >>>> VDPA_ATTR_MAX, > >>>> }; > >>>> -- > >>>> 2.31.1 > >>>> >