> From: Zhu, Lingshan <[email protected]> > Sent: Tuesday, July 26, 2022 7:03 AM > > On 7/24/2022 11:21 PM, Parav Pandit wrote: > > > >> From: Zhu, Lingshan <[email protected]> > >> Sent: Saturday, July 23, 2022 7:24 AM > >> > >> > >> On 7/22/2022 9:12 PM, Parav Pandit wrote: > >>>> From: Zhu Lingshan <[email protected]> > >>>> Sent: Friday, July 22, 2022 7:53 AM > >>>> > >>>> 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 <[email protected]> > >>>> --- > >>>> drivers/vdpa/vdpa.c | 13 +++++++++---- > >>>> include/uapi/linux/vdpa.h | 1 + > >>>> 2 files changed, 10 insertions(+), 4 deletions(-) > >>>> > >>>> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index > >>>> ebf2f363fbe7..9b0e39b2f022 100644 > >>>> --- a/drivers/vdpa/vdpa.c > >>>> +++ b/drivers/vdpa/vdpa.c > >>>> @@ -815,7 +815,7 @@ 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 +832,17 @@ 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); > >>>> + 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..39f1c3d7c112 100644 > >>>> --- a/include/uapi/linux/vdpa.h > >>>> +++ b/include/uapi/linux/vdpa.h > >>>> @@ -47,6 +47,7 @@ enum vdpa_attr { > >>>> VDPA_ATTR_DEV_NEGOTIATED_FEATURES, /* u64 */ > >>>> VDPA_ATTR_DEV_MGMTDEV_MAX_VQS, /* u32 */ > >>>> VDPA_ATTR_DEV_SUPPORTED_FEATURES, /* u64 */ > >>>> + VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, /* u64 */ > >>>> > >>> I have answered in previous emails. > >>> I disagree with the change. > >>> Please reuse VDPA_ATTR_DEV_SUPPORTED_FEATURES. > >> I believe we have already discussed this before in the V3 thread. > >> I have told you that reusing this attr will lead to a new race condition. > >> > > Returning attribute cannot lead to any race condition. > Please refer to our discussion in the V3 series, I have explained if re-use > this > attr, it will be a multiple consumers and multiple produces model, it is a > typical racing condition.
I read the emails with subject = " Re: [PATCH V3 3/6] vDPA: allow userspace to query features of a vDPA device" I couldn’t find multiple consumers multiple producers working on same nla message. _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
