From: Baolu Lu <baolu.lu@linux.intel.com> To: "Tian, Kevin" <kevin.tian@intel.com>, Joerg Roedel <joro@8bytes.org>, Jason Gunthorpe <jgg@nvidia.com>, 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>, "Jiang, Dave" <dave.jiang@intel.com>, Vinod Koul <vkoul@kernel.org> Cc: baolu.lu@linux.intel.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>, Jean-Philippe Brucker <jean-philippe@linaro.org> Subject: Re: [PATCH v7 03/10] iommu/sva: Add iommu_sva_domain support Date: Wed, 25 May 2022 12:50:04 +0800 [thread overview] Message-ID: <caae0926-b8f8-a64d-5c33-441e33d0c1dc@linux.intel.com> (raw) In-Reply-To: <BN9PR11MB5276982C37DFF0FEFC45BDD68CD79@BN9PR11MB5276.namprd11.prod.outlook.com> On 2022/5/24 17:39, Tian, Kevin wrote: >> From: Lu Baolu <baolu.lu@linux.intel.com> >> Sent: Thursday, May 19, 2022 3:21 PM >> >> The iommu_sva_domain represents a hardware pagetable that the IOMMU >> hardware could use for SVA translation. This adds some infrastructure >> to support SVA domain in the iommu common layer. It includes: >> >> - Add a new struct iommu_sva_domain and new IOMMU_DOMAIN_SVA >> domain >> type. >> - Add a new domain ops pointer in iommu_ops. The IOMMU drivers that >> support SVA should provide the callbacks. >> - Add helpers to allocate and free an SVA domain. >> - Add helpers to set an SVA domain to a device and the reverse >> operation. >> >> Some buses, like PCI, route packets without considering the PASID value. >> Thus a DMA target address with PASID might be treated as P2P if the >> address falls into the MMIO BAR of other devices in the group. To make >> things simple, the attach/detach interfaces only apply to devices >> belonging to the singleton groups, and the singleton is immutable in >> fabric i.e. not affected by hotplug. >> >> The iommu_set/block_device_pasid() can be used for other purposes, >> such as kernel DMA with pasid, mediation device, etc. Hence, it is put >> in the iommu.c. > > usually we have 'set/clear' pair or 'allow/block'. Having 'set' paired > with 'block' doesn't read very clearly. Yes. Let's still use the attach/detach semantics. > >> +static bool device_group_immutable_singleton(struct device *dev) >> +{ >> + struct iommu_group *group = iommu_group_get(dev); > > what about passing group as the parameter since the caller will > get the group again right after calling this function? In that case > the function could be renamed as: > > iommu_group_immutable_singleton() > > or be shorter: > > iommu_group_fixed_singleton() Fair enough. I will tune it as below: +static bool iommu_group_immutable_singleton(struct iommu_group *group) +{ + int count; + + mutex_lock(&group->mutex); + count = iommu_group_device_count(group); + mutex_unlock(&group->mutex); + + if (count != 1) + return false; + + /* + * The PCI device could be considered to be fully isolated if all + * devices on the path from the device to the host-PCI bridge are + * protected from peer-to-peer DMA by ACS. + */ + if (dev_is_pci(dev)) + return pci_acs_path_enabled(to_pci_dev(dev), NULL, + REQ_ACS_FLAGS); + + /* + * Otherwise, the device came from DT/ACPI, assume it is static and + * then singleton can know from the device count in the group. + */ + return true; +} > >> + int count; >> + >> + if (!group) >> + return false; >> + >> + mutex_lock(&group->mutex); >> + count = iommu_group_device_count(group); >> + mutex_unlock(&group->mutex); >> + iommu_group_put(group); >> + >> + if (count != 1) >> + return false; > > For non-pci devices above doesn't check anything against immutable. > Please add some comment to explain why doing so is correct. Yes, as above code shows. > >> + >> + /* >> + * The PCI device could be considered to be fully isolated if all >> + * devices on the path from the device to the host-PCI bridge are >> + * protected from peer-to-peer DMA by ACS. >> + */ >> + if (dev_is_pci(dev)) >> + return pci_acs_path_enabled(to_pci_dev(dev), NULL, >> + REQ_ACS_FLAGS); >> + >> + return true; >> +} >> + Best regards, baolu
WARNING: multiple messages have this Message-ID (diff)
From: Baolu Lu <baolu.lu@linux.intel.com> To: "Tian, Kevin" <kevin.tian@intel.com>, Joerg Roedel <joro@8bytes.org>, Jason Gunthorpe <jgg@nvidia.com>, 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>, "Jiang, Dave" <dave.jiang@intel.com>, Vinod Koul <vkoul@kernel.org> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>, "Pan, Jacob jun" <jacob.jun.pan@intel.com> Subject: Re: [PATCH v7 03/10] iommu/sva: Add iommu_sva_domain support Date: Wed, 25 May 2022 12:50:04 +0800 [thread overview] Message-ID: <caae0926-b8f8-a64d-5c33-441e33d0c1dc@linux.intel.com> (raw) In-Reply-To: <BN9PR11MB5276982C37DFF0FEFC45BDD68CD79@BN9PR11MB5276.namprd11.prod.outlook.com> On 2022/5/24 17:39, Tian, Kevin wrote: >> From: Lu Baolu <baolu.lu@linux.intel.com> >> Sent: Thursday, May 19, 2022 3:21 PM >> >> The iommu_sva_domain represents a hardware pagetable that the IOMMU >> hardware could use for SVA translation. This adds some infrastructure >> to support SVA domain in the iommu common layer. It includes: >> >> - Add a new struct iommu_sva_domain and new IOMMU_DOMAIN_SVA >> domain >> type. >> - Add a new domain ops pointer in iommu_ops. The IOMMU drivers that >> support SVA should provide the callbacks. >> - Add helpers to allocate and free an SVA domain. >> - Add helpers to set an SVA domain to a device and the reverse >> operation. >> >> Some buses, like PCI, route packets without considering the PASID value. >> Thus a DMA target address with PASID might be treated as P2P if the >> address falls into the MMIO BAR of other devices in the group. To make >> things simple, the attach/detach interfaces only apply to devices >> belonging to the singleton groups, and the singleton is immutable in >> fabric i.e. not affected by hotplug. >> >> The iommu_set/block_device_pasid() can be used for other purposes, >> such as kernel DMA with pasid, mediation device, etc. Hence, it is put >> in the iommu.c. > > usually we have 'set/clear' pair or 'allow/block'. Having 'set' paired > with 'block' doesn't read very clearly. Yes. Let's still use the attach/detach semantics. > >> +static bool device_group_immutable_singleton(struct device *dev) >> +{ >> + struct iommu_group *group = iommu_group_get(dev); > > what about passing group as the parameter since the caller will > get the group again right after calling this function? In that case > the function could be renamed as: > > iommu_group_immutable_singleton() > > or be shorter: > > iommu_group_fixed_singleton() Fair enough. I will tune it as below: +static bool iommu_group_immutable_singleton(struct iommu_group *group) +{ + int count; + + mutex_lock(&group->mutex); + count = iommu_group_device_count(group); + mutex_unlock(&group->mutex); + + if (count != 1) + return false; + + /* + * The PCI device could be considered to be fully isolated if all + * devices on the path from the device to the host-PCI bridge are + * protected from peer-to-peer DMA by ACS. + */ + if (dev_is_pci(dev)) + return pci_acs_path_enabled(to_pci_dev(dev), NULL, + REQ_ACS_FLAGS); + + /* + * Otherwise, the device came from DT/ACPI, assume it is static and + * then singleton can know from the device count in the group. + */ + return true; +} > >> + int count; >> + >> + if (!group) >> + return false; >> + >> + mutex_lock(&group->mutex); >> + count = iommu_group_device_count(group); >> + mutex_unlock(&group->mutex); >> + iommu_group_put(group); >> + >> + if (count != 1) >> + return false; > > For non-pci devices above doesn't check anything against immutable. > Please add some comment to explain why doing so is correct. Yes, as above code shows. > >> + >> + /* >> + * The PCI device could be considered to be fully isolated if all >> + * devices on the path from the device to the host-PCI bridge are >> + * protected from peer-to-peer DMA by ACS. >> + */ >> + if (dev_is_pci(dev)) >> + return pci_acs_path_enabled(to_pci_dev(dev), NULL, >> + REQ_ACS_FLAGS); >> + >> + return true; >> +} >> + Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2022-05-25 4:50 UTC|newest] Thread overview: 100+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-05-19 7:20 [PATCH v7 00/10] iommu: SVA and IOPF refactoring Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 7:20 ` [PATCH v7 01/10] iommu: Add pasids field in struct iommu_device Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 10:37 ` Jean-Philippe Brucker 2022-05-19 10:37 ` Jean-Philippe Brucker 2022-05-19 11:55 ` Baolu Lu 2022-05-19 11:55 ` Baolu Lu 2022-05-24 9:24 ` Tian, Kevin 2022-05-24 9:24 ` Tian, Kevin 2022-05-25 2:03 ` Baolu Lu 2022-05-25 2:03 ` Baolu Lu 2022-05-25 2:13 ` Baolu Lu 2022-05-25 2:13 ` Baolu Lu 2022-05-19 7:20 ` [PATCH v7 02/10] iommu: Remove SVM_FLAG_SUPERVISOR_MODE support Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 16:22 ` Jean-Philippe Brucker 2022-05-19 16:22 ` Jean-Philippe Brucker 2022-05-24 9:27 ` Tian, Kevin 2022-05-24 9:27 ` Tian, Kevin 2022-05-19 7:20 ` [PATCH v7 03/10] iommu/sva: Add iommu_sva_domain support Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 16:33 ` Jean-Philippe Brucker 2022-05-19 16:33 ` Jean-Philippe Brucker 2022-05-20 4:55 ` Baolu Lu 2022-05-20 4:55 ` Baolu Lu 2022-05-23 7:12 ` Baolu Lu 2022-05-23 7:12 ` Baolu Lu 2022-05-24 9:44 ` Tian, Kevin 2022-05-24 9:44 ` Tian, Kevin 2022-05-25 2:18 ` Baolu Lu 2022-05-25 2:18 ` Baolu Lu 2022-05-24 9:39 ` Tian, Kevin 2022-05-24 9:39 ` Tian, Kevin 2022-05-24 13:38 ` Jason Gunthorpe 2022-05-24 13:38 ` Jason Gunthorpe via iommu 2022-05-25 0:44 ` Tian, Kevin 2022-05-25 0:44 ` Tian, Kevin 2022-05-25 2:38 ` Baolu Lu 2022-05-25 2:38 ` Baolu Lu 2022-05-25 4:50 ` Baolu Lu [this message] 2022-05-25 4:50 ` Baolu Lu 2022-05-24 13:44 ` Jason Gunthorpe 2022-05-24 13:44 ` Jason Gunthorpe via iommu 2022-05-25 5:19 ` Baolu Lu 2022-05-25 5:19 ` Baolu Lu 2022-05-25 15:25 ` Jason Gunthorpe 2022-05-25 15:25 ` Jason Gunthorpe via iommu 2022-05-26 1:03 ` Baolu Lu 2022-05-26 1:03 ` Baolu Lu 2022-05-25 5:33 ` Baolu Lu 2022-05-25 5:33 ` Baolu Lu 2022-05-24 14:36 ` Robin Murphy 2022-05-24 14:36 ` Robin Murphy 2022-05-25 6:20 ` Baolu Lu 2022-05-25 6:20 ` Baolu Lu 2022-05-25 10:07 ` Robin Murphy 2022-05-25 10:07 ` Robin Murphy 2022-05-25 11:06 ` Jean-Philippe Brucker 2022-05-25 11:06 ` Jean-Philippe Brucker 2022-05-25 13:11 ` Baolu Lu 2022-05-25 13:11 ` Baolu Lu 2022-05-19 7:20 ` [PATCH v7 04/10] iommu/vt-d: Add SVA domain support Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 7:20 ` [PATCH v7 05/10] arm-smmu-v3/sva: " Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 16:37 ` Jean-Philippe Brucker 2022-05-19 16:37 ` Jean-Philippe Brucker 2022-05-19 7:20 ` [PATCH v7 06/10] iommu/sva: Refactoring iommu_sva_bind/unbind_device() Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 16:39 ` Jean-Philippe Brucker 2022-05-19 16:39 ` Jean-Philippe Brucker 2022-05-20 6:38 ` Baolu Lu 2022-05-20 6:38 ` Baolu Lu 2022-05-20 11:28 ` Jean-Philippe Brucker 2022-05-20 11:28 ` Jean-Philippe Brucker 2022-05-23 3:07 ` Baolu Lu 2022-05-23 3:07 ` Baolu Lu 2022-05-24 10:22 ` Tian, Kevin 2022-05-24 10:22 ` Tian, Kevin 2022-05-24 10:57 ` Jean-Philippe Brucker 2022-05-24 10:57 ` Jean-Philippe Brucker 2022-05-25 2:04 ` Tian, Kevin 2022-05-25 2:04 ` Tian, Kevin 2022-05-25 7:29 ` Jean-Philippe Brucker 2022-05-25 7:29 ` Jean-Philippe Brucker 2022-06-02 6:46 ` Tian, Kevin 2022-06-02 6:46 ` Tian, Kevin 2022-05-19 7:20 ` [PATCH v7 07/10] iommu: Remove SVA related callbacks from iommu ops Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-24 10:23 ` Tian, Kevin 2022-05-24 10:23 ` Tian, Kevin 2022-05-19 7:20 ` [PATCH v7 08/10] iommu: Prepare IOMMU domain for IOPF Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 16:40 ` Jean-Philippe Brucker 2022-05-19 16:40 ` Jean-Philippe Brucker 2022-05-19 7:20 ` [PATCH v7 09/10] iommu: Per-domain I/O page fault handling Lu Baolu 2022-05-19 7:20 ` Lu Baolu 2022-05-19 7:20 ` [PATCH v7 10/10] iommu: Rename iommu-sva-lib.{c,h} Lu Baolu 2022-05-19 7:20 ` Lu Baolu
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