From: Parav Pandit <parav@nvidia.com> To: "Zhu, Lingshan" <lingshan.zhu@intel.com>, Jason Wang <jasowang@redhat.com>, "mst@redhat.com" <mst@redhat.com> Cc: "virtualization@lists.linux-foundation.org" <virtualization@lists.linux-foundation.org>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "xieyongji@bytedance.com" <xieyongji@bytedance.com>, "gautam.dawar@amd.com" <gautam.dawar@amd.com> Subject: RE: [PATCH V3 3/6] vDPA: allow userspace to query features of a vDPA device Date: Tue, 5 Jul 2022 17:01:24 +0000 [thread overview] Message-ID: <PH0PR12MB54816A1864BADD420A2674E8DC819@PH0PR12MB5481.namprd12.prod.outlook.com> (raw) In-Reply-To: <a59209f3-9005-b9f6-6f27-e136443aa3e1@intel.com> > From: Zhu, Lingshan <lingshan.zhu@intel.com> > Sent: Tuesday, July 5, 2022 12:56 PM > > Both can be queried simultaneously. Each will return their own feature bits > using same attribute. > > It wont lead to the race. > How? It is just a piece of memory, xxxx[attr], do you see locks in > nla_put_u64_64bit()? It is a typical race condition, data accessed by multiple > producers / consumers. No. There is no race condition in here. And new attribute enum by no means avoid any race. Data put using nla_put cannot be accessed until they are transferred. > And re-use a netlink attr is really confusing. Please put comment for this variable explaining why it is shared for the exception. Before that lets start, can you share a real world example of when this feature bitmap will have different value than the mgmt. device bitmap value? > > > >> IMHO, I don't see any advantages of re-using this attr. > > We don’t want to continue this mess of VDPA_DEV prefix for new > attributes due to previous wrong naming. > as you point out before, is is a wrong naming, we can't re-nmme it because > we don't want to break uAPI, so there needs a new attr, if you don't like the > name VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, it is more than > welcome to suggest a new one > > Thanks
WARNING: multiple messages have this Message-ID (diff)
From: Parav Pandit via Virtualization <virtualization@lists.linux-foundation.org> To: "Zhu, Lingshan" <lingshan.zhu@intel.com>, Jason Wang <jasowang@redhat.com>, "mst@redhat.com" <mst@redhat.com> Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "xieyongji@bytedance.com" <xieyongji@bytedance.com>, "gautam.dawar@amd.com" <gautam.dawar@amd.com>, "virtualization@lists.linux-foundation.org" <virtualization@lists.linux-foundation.org> Subject: RE: [PATCH V3 3/6] vDPA: allow userspace to query features of a vDPA device Date: Tue, 5 Jul 2022 17:01:24 +0000 [thread overview] Message-ID: <PH0PR12MB54816A1864BADD420A2674E8DC819@PH0PR12MB5481.namprd12.prod.outlook.com> (raw) In-Reply-To: <a59209f3-9005-b9f6-6f27-e136443aa3e1@intel.com> > From: Zhu, Lingshan <lingshan.zhu@intel.com> > Sent: Tuesday, July 5, 2022 12:56 PM > > Both can be queried simultaneously. Each will return their own feature bits > using same attribute. > > It wont lead to the race. > How? It is just a piece of memory, xxxx[attr], do you see locks in > nla_put_u64_64bit()? It is a typical race condition, data accessed by multiple > producers / consumers. No. There is no race condition in here. And new attribute enum by no means avoid any race. Data put using nla_put cannot be accessed until they are transferred. > And re-use a netlink attr is really confusing. Please put comment for this variable explaining why it is shared for the exception. Before that lets start, can you share a real world example of when this feature bitmap will have different value than the mgmt. device bitmap value? > > > >> IMHO, I don't see any advantages of re-using this attr. > > We don’t want to continue this mess of VDPA_DEV prefix for new > attributes due to previous wrong naming. > as you point out before, is is a wrong naming, we can't re-nmme it because > we don't want to break uAPI, so there needs a new attr, if you don't like the > name VDPA_ATTR_VDPA_DEV_SUPPORTED_FEATURES, it is more than > welcome to suggest a new one > > Thanks _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2022-07-05 17:01 UTC|newest] Thread overview: 186+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-07-01 13:28 [PATCH V3 0/6] ifcvf/vDPA: support query device config space through netlink Zhu Lingshan 2022-07-01 13:28 ` [PATCH V3 1/6] vDPA/ifcvf: get_config_size should return a value no greater than dev implementation Zhu Lingshan 2022-07-04 4:39 ` Jason Wang 2022-07-04 4:39 ` Jason Wang 2022-07-08 6:44 ` Zhu, Lingshan 2022-07-13 5:44 ` Michael S. Tsirkin 2022-07-13 5:44 ` Michael S. Tsirkin 2022-07-13 7:52 ` Zhu, Lingshan 2022-07-13 5:31 ` Michael S. Tsirkin 2022-07-13 5:31 ` Michael S. Tsirkin 2022-07-13 7:48 ` Zhu, Lingshan 2022-07-01 13:28 ` [PATCH V3 2/6] vDPA/ifcvf: support userspace to query features and MQ of a management device Zhu Lingshan 2022-07-04 4:43 ` Jason Wang 2022-07-04 4:43 ` Jason Wang 2022-07-08 6:54 ` Zhu, Lingshan 2022-07-01 13:28 ` [PATCH V3 3/6] vDPA: allow userspace to query features of a vDPA device Zhu Lingshan 2022-07-01 22:02 ` Parav Pandit 2022-07-01 22:02 ` Parav Pandit via Virtualization 2022-07-04 4:46 ` Jason Wang 2022-07-04 4:46 ` Jason Wang 2022-07-04 12:53 ` Parav Pandit via Virtualization 2022-07-04 12:53 ` Parav Pandit 2022-07-05 7:59 ` Zhu, Lingshan 2022-07-05 11:56 ` Parav Pandit 2022-07-05 11:56 ` Parav Pandit via Virtualization 2022-07-05 16:56 ` Zhu, Lingshan 2022-07-05 17:01 ` Parav Pandit [this message] 2022-07-05 17:01 ` Parav Pandit via Virtualization 2022-07-06 2:25 ` Zhu, Lingshan 2022-07-06 2:28 ` Parav Pandit 2022-07-06 2:28 ` Parav Pandit via Virtualization 2022-07-23 11:27 ` Zhu, Lingshan 2022-07-24 15:23 ` Parav Pandit 2022-07-24 15:23 ` Parav Pandit via Virtualization 2022-07-27 8:15 ` Si-Wei Liu 2022-07-27 8:15 ` Si-Wei Liu 2022-07-27 11:38 ` Zhu, Lingshan 2022-07-08 6:16 ` Zhu, Lingshan 2022-07-08 16:13 ` Parav Pandit 2022-07-08 16:13 ` Parav Pandit via Virtualization 2022-07-11 2:18 ` Zhu, Lingshan 2022-07-01 13:28 ` [PATCH V3 4/6] vDPA: !FEATURES_OK should not block querying device config space Zhu Lingshan 2022-07-01 22:12 ` Parav Pandit 2022-07-01 22:12 ` Parav Pandit via Virtualization 2022-07-08 6:22 ` Zhu, Lingshan 2022-07-13 5:23 ` Michael S. Tsirkin 2022-07-13 5:23 ` Michael S. Tsirkin 2022-07-13 7:46 ` Zhu, Lingshan 2022-07-27 9:43 ` Si-Wei Liu [not found] ` <63242254-ba84-6810-dad8-34f900b97f2f@intel.com> 2022-07-28 0:56 ` Si-Wei Liu 2022-07-28 2:06 ` Jason Wang 2022-07-28 2:06 ` Jason Wang 2022-07-28 7:08 ` Si-Wei Liu 2022-07-28 7:08 ` Si-Wei Liu 2022-07-28 7:36 ` Jason Wang 2022-07-28 7:36 ` Jason Wang 2022-07-28 7:44 ` Zhu, Lingshan 2022-07-28 8:20 ` spec clarification (was Re: [PATCH V3 4/6] vDPA: !FEATURES_OK should not block querying device config space) Si-Wei Liu 2022-07-28 11:28 ` Michael S. Tsirkin 2022-07-28 11:28 ` [virtio-comment] " Michael S. Tsirkin 2022-07-28 11:28 ` Michael S. Tsirkin 2022-07-28 11:35 ` [PATCH V3 4/6] vDPA: !FEATURES_OK should not block querying device config space Michael S. Tsirkin 2022-07-28 11:35 ` Michael S. Tsirkin 2022-07-28 22:12 ` Si-Wei Liu 2022-07-28 22:12 ` Si-Wei Liu [not found] ` <00e2e07e-1a2e-7af8-a060-cc9034e0d33f@intel.com> 2022-07-28 21:48 ` Si-Wei Liu [not found] ` <c143e2da-208e-b046-9b8f-1780f75ed3e6@intel.com> 2022-07-29 20:55 ` Si-Wei Liu 2022-07-29 20:55 ` Si-Wei Liu 2022-08-01 4:44 ` Jason Wang 2022-08-01 4:44 ` Jason Wang 2022-08-01 22:53 ` Si-Wei Liu 2022-08-01 22:53 ` Si-Wei Liu 2022-08-01 22:58 ` Si-Wei Liu 2022-08-01 22:58 ` Si-Wei Liu 2022-08-02 6:33 ` Jason Wang 2022-08-02 6:33 ` Jason Wang 2022-08-03 1:26 ` Si-Wei Liu 2022-08-03 1:26 ` Si-Wei Liu 2022-08-03 2:30 ` Zhu, Lingshan 2022-08-03 23:09 ` Si-Wei Liu 2022-08-03 23:09 ` Si-Wei Liu 2022-08-04 1:41 ` Zhu, Lingshan 2022-08-04 1:41 ` Zhu, Lingshan 2022-07-01 13:28 ` [PATCH V3 5/6] vDPA: answer num of queue pairs = 1 to userspace when VIRTIO_NET_F_MQ == 0 Zhu Lingshan 2022-07-01 22:07 ` Parav Pandit 2022-07-01 22:07 ` Parav Pandit via Virtualization 2022-07-08 6:21 ` Zhu, Lingshan 2022-07-08 16:23 ` Parav Pandit via Virtualization 2022-07-08 16:23 ` Parav Pandit 2022-07-11 2:29 ` Zhu, Lingshan 2022-07-12 16:48 ` Parav Pandit 2022-07-12 16:48 ` Parav Pandit via Virtualization 2022-07-13 3:03 ` Zhu, Lingshan 2022-07-13 3:06 ` Parav Pandit 2022-07-13 3:06 ` Parav Pandit via Virtualization 2022-07-13 3:45 ` Zhu, Lingshan 2022-07-26 15:56 ` Parav Pandit 2022-07-26 15:56 ` Parav Pandit via Virtualization 2022-07-26 19:52 ` Michael S. Tsirkin 2022-07-26 19:52 ` Michael S. Tsirkin 2022-07-26 20:49 ` Parav Pandit 2022-07-26 20:49 ` Parav Pandit via Virtualization 2022-07-27 2:14 ` Zhu, Lingshan 2022-07-27 2:17 ` Parav Pandit 2022-07-27 2:17 ` Parav Pandit via Virtualization 2022-07-27 2:53 ` Zhu, Lingshan 2022-07-27 3:47 ` Parav Pandit 2022-07-27 3:47 ` Parav Pandit via Virtualization 2022-07-27 4:24 ` Zhu, Lingshan 2022-07-27 6:01 ` Michael S. Tsirkin 2022-07-27 6:01 ` Michael S. Tsirkin 2022-07-27 6:25 ` Zhu, Lingshan 2022-07-27 6:56 ` Jason Wang 2022-07-27 6:56 ` Jason Wang 2022-07-27 9:05 ` Michael S. Tsirkin 2022-07-27 9:05 ` Michael S. Tsirkin 2022-07-27 6:54 ` Jason Wang 2022-07-27 6:54 ` Jason Wang 2022-07-27 9:02 ` Michael S. Tsirkin 2022-07-27 9:02 ` Michael S. Tsirkin 2022-07-27 9:50 ` Jason Wang 2022-07-27 9:50 ` Jason Wang 2022-07-27 15:45 ` Michael S. Tsirkin 2022-07-27 15:45 ` Michael S. Tsirkin 2022-07-28 1:21 ` Jason Wang 2022-07-28 1:21 ` Jason Wang 2022-07-28 3:46 ` Zhu, Lingshan 2022-07-28 5:53 ` Jason Wang 2022-07-28 5:53 ` Jason Wang 2022-07-28 6:02 ` Zhu, Lingshan 2022-07-28 6:41 ` Michael S. Tsirkin 2022-07-28 6:41 ` Michael S. Tsirkin 2022-08-01 4:50 ` Jason Wang 2022-08-01 4:50 ` Jason Wang 2022-07-27 7:50 ` Si-Wei Liu 2022-07-27 7:50 ` Si-Wei Liu 2022-07-27 9:01 ` Michael S. Tsirkin 2022-07-27 9:01 ` Michael S. Tsirkin 2022-07-27 10:09 ` Si-Wei Liu 2022-07-27 10:09 ` Si-Wei Liu 2022-07-27 11:54 ` Zhu, Lingshan 2022-07-28 1:41 ` Si-Wei Liu 2022-07-28 1:41 ` Si-Wei Liu 2022-07-28 2:44 ` Zhu, Lingshan 2022-07-28 21:54 ` Si-Wei Liu 2022-07-28 21:54 ` Si-Wei Liu 2022-07-29 2:07 ` Zhu, Lingshan 2022-07-27 15:48 ` Michael S. Tsirkin 2022-07-27 15:48 ` Michael S. Tsirkin 2022-07-28 7:22 ` Si-Wei Liu 2022-07-13 5:26 ` Michael S. Tsirkin 2022-07-13 5:26 ` Michael S. Tsirkin 2022-07-13 7:47 ` Zhu, Lingshan 2022-07-26 15:54 ` Parav Pandit via Virtualization 2022-07-26 15:54 ` Parav Pandit 2022-07-26 19:48 ` Michael S. Tsirkin 2022-07-26 19:48 ` Michael S. Tsirkin 2022-07-26 20:53 ` Parav Pandit 2022-07-26 20:53 ` Parav Pandit via Virtualization 2022-07-27 1:56 ` Zhu, Lingshan 2022-07-27 2:11 ` Zhu, Lingshan 2022-07-01 13:28 ` [PATCH V3 6/6] vDPA: fix 'cast to restricted le16' warnings in vdpa.c Zhu Lingshan 2022-07-01 22:18 ` Parav Pandit 2022-07-01 22:18 ` Parav Pandit via Virtualization 2022-07-08 6:25 ` Zhu, Lingshan 2022-07-08 16:08 ` Parav Pandit 2022-07-08 16:08 ` Parav Pandit via Virtualization 2022-07-29 8:53 ` Michael S. Tsirkin 2022-07-29 8:53 ` Michael S. Tsirkin 2022-07-29 9:07 ` Zhu, Lingshan 2022-07-29 9:17 ` Michael S. Tsirkin 2022-07-29 9:17 ` Michael S. Tsirkin 2022-07-29 9:20 ` Zhu, Lingshan 2022-07-29 9:23 ` Michael S. Tsirkin 2022-07-29 9:23 ` Michael S. Tsirkin 2022-07-29 9:35 ` Zhu, Lingshan 2022-07-29 9:39 ` Michael S. Tsirkin 2022-07-29 9:39 ` Michael S. Tsirkin 2022-07-29 10:01 ` Zhu, Lingshan 2022-07-29 10:16 ` Michael S. Tsirkin 2022-07-29 10:16 ` Michael S. Tsirkin 2022-07-29 10:18 ` Zhu, Lingshan 2022-08-01 4:33 ` Jason Wang 2022-08-01 4:33 ` Jason Wang 2022-08-01 6:25 ` Michael S. Tsirkin 2022-08-01 6:25 ` Michael S. Tsirkin
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