From: Lu Baolu <baolu.lu@linux.intel.com> To: Jason Gunthorpe <jgg@nvidia.com> Cc: baolu.lu@linux.intel.com, "Tian, Kevin" <kevin.tian@intel.com>, Joerg Roedel <joro@8bytes.org>, Christoph Hellwig <hch@infradead.org>, "Raj, Ashok" <ashok.raj@intel.com>, Will Deacon <will@kernel.org>, Robin Murphy <robin.murphy@arm.com>, Jean-Philippe Brucker <jean-philippe@linaro.com>, Eric Auger <eric.auger@redhat.com>, "Liu, Yi L" <yi.l.liu@intel.com>, "Pan, Jacob jun" <jacob.jun.pan@intel.com>, "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH RFC v2 02/11] iommu: Add iommu_group_singleton_lockdown() Date: Tue, 5 Apr 2022 14:12:42 +0800 [thread overview] Message-ID: <5ca5d34a-2394-b8bd-837b-cd6bf3301989@linux.intel.com> (raw) In-Reply-To: <20220404172403.GO2120790@nvidia.com> On 2022/4/5 1:24, Jason Gunthorpe wrote: > On Mon, Apr 04, 2022 at 01:43:49PM +0800, Lu Baolu wrote: >> On 2022/3/30 19:58, Jason Gunthorpe wrote: >>>>> Testing the group size is inherently the wrong test to make. >>>> What is your suggestion then? >>> Add a flag to the group that positively indicates the group can never >>> have more than one member, even after hot plug. eg because it is >>> impossible due to ACS, or lack of bridges, and so on. >> >> The check method seems to be bus specific. For platform devices, perhaps >> this kind of information should be retrieved from firmware interfaces >> like APCI or DT. >> >> From this point of view, would it be simpler and more reasonable for the >> device driver to do such check? After all, it is the device driver that >> decides whether to provide SVA services to the application via uacce. > > The check has to do with the interconnect, not the device - I don't > see how a device driver would know any better. I'm worried about how to support this group flag for devices that are not connected to the system through PCI buses. If IOMMU can support sva_bind() only when this flag is set, the SVA on many devices cannot be supported. Or this flag is always set for non PCI devices by default? > > Why do you bring up uacce? Nothing should need uacce to access SVA. The uacce is irrelevant here. Best regards, baolu
WARNING: multiple messages have this Message-ID (diff)
From: Lu Baolu <baolu.lu@linux.intel.com> To: Jason Gunthorpe <jgg@nvidia.com> Cc: "Tian, Kevin" <kevin.tian@intel.com>, "Raj, Ashok" <ashok.raj@intel.com>, Robin Murphy <robin.murphy@arm.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Christoph Hellwig <hch@infradead.org>, Jean-Philippe Brucker <jean-philippe@linaro.com>, "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>, "Pan, Jacob jun" <jacob.jun.pan@intel.com>, Will Deacon <will@kernel.org> Subject: Re: [PATCH RFC v2 02/11] iommu: Add iommu_group_singleton_lockdown() Date: Tue, 5 Apr 2022 14:12:42 +0800 [thread overview] Message-ID: <5ca5d34a-2394-b8bd-837b-cd6bf3301989@linux.intel.com> (raw) In-Reply-To: <20220404172403.GO2120790@nvidia.com> On 2022/4/5 1:24, Jason Gunthorpe wrote: > On Mon, Apr 04, 2022 at 01:43:49PM +0800, Lu Baolu wrote: >> On 2022/3/30 19:58, Jason Gunthorpe wrote: >>>>> Testing the group size is inherently the wrong test to make. >>>> What is your suggestion then? >>> Add a flag to the group that positively indicates the group can never >>> have more than one member, even after hot plug. eg because it is >>> impossible due to ACS, or lack of bridges, and so on. >> >> The check method seems to be bus specific. For platform devices, perhaps >> this kind of information should be retrieved from firmware interfaces >> like APCI or DT. >> >> From this point of view, would it be simpler and more reasonable for the >> device driver to do such check? After all, it is the device driver that >> decides whether to provide SVA services to the application via uacce. > > The check has to do with the interconnect, not the device - I don't > see how a device driver would know any better. I'm worried about how to support this group flag for devices that are not connected to the system through PCI buses. If IOMMU can support sva_bind() only when this flag is set, the SVA on many devices cannot be supported. Or this flag is always set for non PCI devices by default? > > Why do you bring up uacce? Nothing should need uacce to access SVA. The uacce is irrelevant here. Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2022-04-05 6:13 UTC|newest] Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-29 5:37 [PATCH RFC v2 00/11] iommu: SVA and IOPF refactoring Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 01/11] iommu: Add pasid_bits field in struct dev_iommu Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 21:00 ` Jacob Pan 2022-03-29 21:00 ` Jacob Pan 2022-03-30 4:30 ` Lu Baolu 2022-03-30 4:30 ` Lu Baolu 2022-03-30 7:05 ` Tian, Kevin 2022-03-30 7:05 ` Tian, Kevin 2022-03-30 11:58 ` Lu Baolu 2022-03-30 11:58 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 02/11] iommu: Add iommu_group_singleton_lockdown() Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 8:42 ` Tian, Kevin 2022-03-29 8:42 ` Tian, Kevin 2022-03-29 11:42 ` Jason Gunthorpe 2022-03-29 11:42 ` Jason Gunthorpe via iommu 2022-03-30 6:50 ` Tian, Kevin 2022-03-30 6:50 ` Tian, Kevin 2022-03-30 11:57 ` Lu Baolu 2022-03-30 11:57 ` Lu Baolu 2022-03-30 11:58 ` Jason Gunthorpe via iommu 2022-03-30 11:58 ` Jason Gunthorpe 2022-03-30 14:12 ` Tian, Kevin 2022-03-30 14:12 ` Tian, Kevin 2022-03-30 14:30 ` Jason Gunthorpe 2022-03-30 14:30 ` Jason Gunthorpe via iommu 2022-04-02 7:12 ` Tian, Kevin 2022-04-02 7:12 ` Tian, Kevin 2022-04-02 23:29 ` Jason Gunthorpe 2022-04-02 23:29 ` Jason Gunthorpe via iommu 2022-04-06 10:02 ` Lu Baolu 2022-04-06 10:02 ` Lu Baolu 2022-04-06 10:44 ` Tian, Kevin 2022-04-06 10:44 ` Tian, Kevin 2022-04-06 11:03 ` Lu Baolu 2022-04-06 11:03 ` Lu Baolu 2022-04-06 23:56 ` Tian, Kevin 2022-04-06 23:56 ` Tian, Kevin 2022-03-30 14:18 ` Tian, Kevin 2022-03-30 14:18 ` Tian, Kevin 2022-03-30 15:04 ` Alex Williamson 2022-03-30 15:04 ` Alex Williamson 2022-04-04 5:43 ` Lu Baolu 2022-04-04 5:43 ` Lu Baolu 2022-04-04 17:24 ` Jason Gunthorpe via iommu 2022-04-04 17:24 ` Jason Gunthorpe 2022-04-05 6:12 ` Lu Baolu [this message] 2022-04-05 6:12 ` Lu Baolu 2022-04-05 14:10 ` Jason Gunthorpe via iommu 2022-04-05 14:10 ` Jason Gunthorpe 2022-04-06 9:51 ` Lu Baolu 2022-04-06 9:51 ` Lu Baolu 2022-04-01 6:20 ` Yi Liu 2022-04-01 6:20 ` Yi Liu 2022-04-01 11:52 ` Jason Gunthorpe 2022-04-01 11:52 ` Jason Gunthorpe via iommu 2022-03-30 4:59 ` Lu Baolu 2022-03-30 4:59 ` Lu Baolu 2022-03-30 6:55 ` Tian, Kevin 2022-03-30 6:55 ` Tian, Kevin 2022-04-01 5:49 ` Yi Liu 2022-04-01 5:49 ` Yi Liu 2022-03-29 5:37 ` [PATCH RFC v2 03/11] iommu/sva: Add iommu_domain type for SVA Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 21:38 ` Jacob Pan 2022-03-29 21:38 ` Jacob Pan 2022-03-30 4:35 ` Lu Baolu 2022-03-30 4:35 ` Lu Baolu 2022-03-30 19:02 ` Jason Gunthorpe 2022-03-30 19:02 ` Jason Gunthorpe via iommu 2022-04-02 8:43 ` Tian, Kevin 2022-04-02 8:43 ` Tian, Kevin 2022-04-02 23:32 ` Jason Gunthorpe 2022-04-02 23:32 ` Jason Gunthorpe via iommu 2022-04-04 6:09 ` Lu Baolu 2022-04-04 6:09 ` Lu Baolu 2022-04-06 1:00 ` Tian, Kevin 2022-04-06 1:00 ` Tian, Kevin 2022-04-06 1:23 ` Jason Gunthorpe via iommu 2022-04-06 1:23 ` Jason Gunthorpe 2022-04-06 5:58 ` Tian, Kevin 2022-04-06 5:58 ` Tian, Kevin 2022-04-06 12:32 ` Robin Murphy 2022-04-06 12:32 ` Robin Murphy 2022-04-06 13:06 ` Jason Gunthorpe via iommu 2022-04-06 13:06 ` Jason Gunthorpe 2022-04-06 13:37 ` Robin Murphy 2022-04-06 13:37 ` Robin Murphy 2022-04-06 14:01 ` Jason Gunthorpe via iommu 2022-04-06 14:01 ` Jason Gunthorpe 2022-04-07 0:11 ` Tian, Kevin 2022-04-07 0:11 ` Tian, Kevin 2022-03-29 5:37 ` [PATCH RFC v2 04/11] iommu: Add attach/detach_dev_pasid domain ops Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-30 19:08 ` Jason Gunthorpe 2022-03-30 19:08 ` Jason Gunthorpe via iommu 2022-04-04 6:47 ` Lu Baolu 2022-04-04 6:47 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 05/11] iommu/vt-d: Remove SVM_FLAG_SUPERVISOR_MODE suport Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 06/11] iommu/vt-d: Add SVA domain support Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-30 19:09 ` Jason Gunthorpe 2022-03-30 19:09 ` Jason Gunthorpe via iommu 2022-04-04 6:52 ` Lu Baolu 2022-04-04 6:52 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 07/11] arm-smmu-v3/sva: " Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 08/11] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-31 20:59 ` Jacob Pan 2022-03-31 20:59 ` Jacob Pan 2022-03-31 22:26 ` Jason Gunthorpe 2022-03-31 22:26 ` Jason Gunthorpe via iommu 2022-04-04 5:55 ` Lu Baolu 2022-04-04 5:55 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 09/11] iommu: Remove SVA related callbacks from iommu ops Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 5:37 ` [PATCH RFC v2 10/11] iommu: Per-domain I/O page fault handling Lu Baolu 2022-03-29 5:37 ` Lu Baolu 2022-03-29 5:38 ` [PATCH RFC v2 11/11] iommu: Rename iommu-sva-lib.{c,h} Lu Baolu 2022-03-29 5:38 ` Lu Baolu
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