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path: root/include/uapi/linux/iommufd.h
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2025-07-18iommufd: Destroy vdevice on idevice destroyXu Yilun
Destroy iommufd_vdevice (vdev) on iommufd_idevice (idev) destruction so that vdev can't outlive idev. idev represents the physical device bound to iommufd, while the vdev represents the virtual instance of the physical device in the VM. The lifecycle of the vdev should not be longer than idev. This doesn't cause real problem on existing use cases cause vdev doesn't impact the physical device, only provides virtualization information. But to extend vdev for Confidential Computing (CC), there are needs to do secure configuration for the vdev, e.g. TSM Bind/Unbind. These configurations should be rolled back on idev destroy, or the external driver (VFIO) functionality may be impact. The idev is created by external driver so its destruction can't fail. The idev implements pre_destroy() op to actively remove its associated vdev before destroying itself. There are 3 cases on idev pre_destroy(): 1. vdev is already destroyed by userspace. No extra handling needed. 2. vdev is still alive. Use iommufd_object_tombstone_user() to destroy vdev and tombstone the vdev ID. 3. vdev is being destroyed by userspace. The vdev ID is already freed, but vdev destroy handler is not completed. This requires multi-threads syncing - vdev holds idev's short term users reference until vdev destruction completes, idev leverages existing wait_shortterm mechanism for syncing. idev should also block any new reference to it after pre_destroy(), or the following wait shortterm would timeout. Introduce a 'destroying' flag, set it to true on idev pre_destroy(). Any attempt to reference idev should honor this flag under the protection of idev->igroup->lock. Link: https://patch.msgid.link/r/20250716070349.1807226-5-yilun.xu@linux.intel.com Originally-by: Nicolin Chen <nicolinc@nvidia.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Co-developed-by: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org> Signed-off-by: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11iommu/tegra241-cmdqv: Add IOMMU_VEVENTQ_TYPE_TEGRA241_CMDQV supportNicolin Chen
Add a new vEVENTQ type for VINTFs that are assigned to the user space. Simply report the two 64-bit LVCMDQ_ERR_MAPs register values. Link: https://patch.msgid.link/r/68161a980da41fa5022841209638aeff258557b5.1752126748.git.nicolinc@nvidia.com Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Pranjal Shrivastava <praan@google.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11iommu/tegra241-cmdqv: Add user-space use supportNicolin Chen
The CMDQV HW supports a user-space use for virtualization cases. It allows the VM to issue guest-level TLBI or ATC_INV commands directly to the queue and executes them without a VMEXIT, as HW will replace the VMID field in a TLBI command and the SID field in an ATC_INV command with the preset VMID and SID. This is built upon the vIOMMU infrastructure by allowing VMM to allocate a VINTF (as a vIOMMU object) and assign VCMDQs (HW QUEUE objs) to the VINTF. So firstly, replace the standard vSMMU model with the VINTF implementation but reuse the standard cache_invalidate op (for unsupported commands) and the standard alloc_domain_nested op (for standard nested STE). Each VINTF has two 64KB MMIO pages (128B per logical VCMDQ): - Page0 (directly accessed by guest) has all the control and status bits. - Page1 (trapped by VMM) has guest-owned queue memory location/size info. VMM should trap the emulated VINTF0's page1 of the guest VM for the guest- level VCMDQ location/size info and forward that to the kernel to translate to a physical memory location to program the VCMDQ HW during an allocation call. Then, it should mmap the assigned VINTF's page0 to the VINTF0 page0 of the guest VM. This allows the guest OS to read and write the guest-own VINTF's page0 for direct control of the VCMDQ HW. For ATC invalidation commands that hold an SID, it requires all devices to register their virtual SIDs to the SID_MATCH registers and their physical SIDs to the pairing SID_REPLACE registers, so that HW can use those as a lookup table to replace those virtual SIDs with the correct physical SIDs. Thus, implement the driver-allocated vDEVICE op with a tegra241_vintf_sid structure to allocate SID_REPLACE and to program the SIDs accordingly. This enables the HW accelerated feature for NVIDIA Grace CPU. Compared to the standard SMMUv3 operating in the nested translation mode trapping CMDQ for TLBI and ATC_INV commands, this gives a huge performance improvement: 70% to 90% reductions of invalidation time were measured by various DMA unmap tests running in a guest OS. Link: https://patch.msgid.link/r/fb0eab83f529440b6aa181798912a6f0afa21eb0.1752126748.git.nicolinc@nvidia.com Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pranjal Shrivastava <praan@google.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11iommufd: Allow an input data_type via iommu_hw_infoNicolin Chen
The iommu_hw_info can output via the out_data_type field the vendor data type from a driver, but this only allows driver to report one data type. Now, with SMMUv3 having a Tegra241 CMDQV implementation, it has two sets of types and data structs to report. One way to support that is to use the same type field bidirectionally. Reuse the same field by adding an "in_data_type", allowing user space to request for a specific type and to get the corresponding data. For backward compatibility, since the ioctl handler has never checked an input value, add an IOMMU_HW_INFO_FLAG_INPUT_TYPE to switch between the old output-only field and the new bidirectional field. Link: https://patch.msgid.link/r/887378a7167e1786d9d13cde0c36263ed61823d7.1752126748.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Pranjal Shrivastava <praan@google.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11iommu: Allow an input type in hw_info opNicolin Chen
The hw_info uAPI will support a bidirectional data_type field that can be used as an input field for user space to request for a specific info data. To prepare for the uAPI update, change the iommu layer first: - Add a new IOMMU_HW_INFO_TYPE_DEFAULT as an input, for which driver can output its only (or firstly) supported type - Update the kdoc accordingly - Roll out the type validation in the existing drivers Link: https://patch.msgid.link/r/00f4a2d3d930721f61367014717b3ba2d1e82a81.1752126748.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Pranjal Shrivastava <praan@google.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctlNicolin Chen
Introduce a new IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl for user space to allocate a HW QUEUE object for a vIOMMU specific HW-accelerated queue, e.g.: - NVIDIA's Virtual Command Queue - AMD vIOMMU's Command Buffer, Event Log Buffers, and PPR Log Buffers Since this is introduced with NVIDIA's VCMDQs that access the guest memory in the physical address space, add an iommufd_hw_queue_alloc_phys() helper that will create an access object to the queue memory in the IOAS, to avoid the mappings of the guest memory from being unmapped, during the life cycle of the HW queue object. AMD's HW will need an hw_queue_init op that is mutually exclusive with the hw_queue_init_phys op, and their case will bypass the access part, i.e. no iommufd_hw_queue_alloc_phys() call. Link: https://patch.msgid.link/r/dab4ace747deb46c1fe70a5c663307f46990ae56.1752126748.git.nicolinc@nvidia.com Reviewed-by: Pranjal Shrivastava <praan@google.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11iommufd/viommu: Introduce IOMMUFD_OBJ_HW_QUEUE and its related structNicolin Chen
Add IOMMUFD_OBJ_HW_QUEUE with an iommufd_hw_queue structure, representing a HW-accelerated queue type of IOMMU's physical queue that can be passed through to a user space VM for direct hardware control, such as: - NVIDIA's Virtual Command Queue - AMD vIOMMU's Command Buffer, Event Log Buffers, and PPR Log Buffers Add new viommu ops for iommufd to communicate with IOMMU drivers to fetch supported HW queue structure size and to forward user space ioctls to the IOMMU drivers for initialization/destroy. As the existing HWs, NVIDIA's VCMDQs access the guest memory via physical addresses, while AMD's Buffers access the guest memory via guest physical addresses (i.e. iova of the nesting parent HWPT). Separate two mutually exclusive hw_queue_init and hw_queue_init_phys ops to indicate whether a vIOMMU HW accesses the guest queue in the guest physical space (via iova) or the host physical space (via pa). In a latter case, the iommufd core will validate the physical pages of a given guest queue, to ensure the underlying physical pages are contiguous and pinned. Since this is introduced with NVIDIA's VCMDQs, add hw_queue_init_phys for now, and leave some notes for hw_queue_init in the near future (for AMD). Either NVIDIA's or AMD's HW is a multi-queue model: NVIDIA's will be only one type in enum iommu_hw_queue_type, while AMD's will be three different types (two of which will have multi queues). Compared to letting the core manage multiple queues with three types per vIOMMU object, it'd be easier for the driver to manage that by having three different driver-structure arrays per vIOMMU object. Thus, pass in the index to the init op. Link: https://patch.msgid.link/r/6939b73699e278e60ce167e911b3d9be68882bad.1752126748.git.nicolinc@nvidia.com Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Pranjal Shrivastava <praan@google.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-10iommufd/viommu: Allow driver-specific user data for a vIOMMU objectNicolin Chen
The new type of vIOMMU for tegra241-cmdqv driver needs a driver-specific user data. So, add data_len/uptr to the iommu_viommu_alloc uAPI and pass it in via the viommu_init iommu op. Link: https://patch.msgid.link/r/2315b0e164b355746387e960745ac9154caec124.1752126748.git.nicolinc@nvidia.com Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Pranjal Shrivastava <praan@google.com> Acked-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-10iommufd: Correct virt_id kdoc at struct iommu_vdevice_allocNicolin Chen
The userspace-api iommufd.rst has described it correctly but the uAPI doc was remained uncorrected. Thus, fix it. Link: https://patch.msgid.link/r/2cdcecaf2babee16fda7545ccad4e5bed7a5032d.1752126748.git.nicolinc@nvidia.com Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-28iommufd: Fix iommu_vevent_header tables markupBagas Sanjaya
Stephen Rothwell reports htmldocs warnings on iommufd_vevent_header tables: Documentation/userspace-api/iommufd:323: ./include/uapi/linux/iommufd.h:1048: CRITICAL: Unexpected section title or transition. ------------------------------------------------------------------------- [docutils] WARNING: kernel-doc './scripts/kernel-doc -rst -enable-lineno -sphinx-version 8.1.3 ./include/uapi/linux/iommufd.h' processing failed with: Documentation/userspace-api/iommufd:323: ./include/uapi/linux/iommufd.h:1048: (SEVERE/4) Unexpected section title or transition. ------------------------------------------------------------------------- These are because Sphinx confuses the tables for section headings. Fix the table markup to squash away above warnings. Fixes: e36ba5ab808e ("iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC") Link: https://patch.msgid.link/r/20250328114654.55840-1-bagasdotme@gmail.com Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/linux-next/20250318213359.5dc56fd1@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-28iommufd: Extend IOMMU_GET_HW_INFO to report PASID capabilityYi Liu
PASID usage requires PASID support in both device and IOMMU. Since the iommu drivers always enable the PASID capability for the device if it is supported, this extends the IOMMU_GET_HW_INFO to report the PASID capability to userspace. Also, enhances the selftest accordingly. Link: https://patch.msgid.link/r/20250321180143.8468-5-yi.l.liu@intel.com Cc: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org> #aarch64 platform Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-25iommufd: Allow allocating PASID-compatible domainYi Liu
The underlying infrastructure has supported the PASID attach and related enforcement per the requirement of the IOMMU_HWPT_ALLOC_PASID flag. This extends iommufd to support PASID compatible domain requested by userspace. Link: https://patch.msgid.link/r/20250321171940.7213-15-yi.l.liu@intel.com Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-18iommu/arm-smmu-v3: Report events that belong to devices attached to vIOMMUNicolin Chen
Aside from the IOPF framework, iommufd provides an additional pathway to report hardware events, via the vEVENTQ of vIOMMU infrastructure. Define an iommu_vevent_arm_smmuv3 uAPI structure, and report stage-1 events in the threaded IRQ handler. Also, add another four event record types that can be forwarded to a VM. Link: https://patch.msgid.link/r/5cf6719682fdfdabffdb08374cdf31ad2466d75a.1741719725.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pranjal Shrivastava <praan@google.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-18iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOCNicolin Chen
Introduce a new IOMMUFD_OBJ_VEVENTQ object for vIOMMU Event Queue that provides user space (VMM) another FD to read the vIOMMU Events. Allow a vIOMMU object to allocate vEVENTQs, with a condition that each vIOMMU can only have one single vEVENTQ per type. Add iommufd_veventq_alloc() with iommufd_veventq_ops for the new ioctl. Link: https://patch.msgid.link/r/21acf0751dd5c93846935ee06f93b9c65eff5e04.1741719725.git.nicolinc@nvidia.com Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-01-21iommufd: Fix struct iommu_hwpt_pgfault init and paddingNicolin Chen
The iommu_hwpt_pgfault is used to report IO page fault data to userspace, but iommufd_fault_fops_read was never zeroing its padding. This leaks the content of the kernel stack memory to userspace. Also, the iommufd uAPI requires explicit padding and use of __aligned_u64 to ensure ABI compatibility's with 32 bit. pahole result, before: struct iommu_hwpt_pgfault { __u32 flags; /* 0 4 */ __u32 dev_id; /* 4 4 */ __u32 pasid; /* 8 4 */ __u32 grpid; /* 12 4 */ __u32 perm; /* 16 4 */ /* XXX 4 bytes hole, try to pack */ __u64 addr; /* 24 8 */ __u32 length; /* 32 4 */ __u32 cookie; /* 36 4 */ /* size: 40, cachelines: 1, members: 8 */ /* sum members: 36, holes: 1, sum holes: 4 */ /* last cacheline: 40 bytes */ }; pahole result, after: struct iommu_hwpt_pgfault { __u32 flags; /* 0 4 */ __u32 dev_id; /* 4 4 */ __u32 pasid; /* 8 4 */ __u32 grpid; /* 12 4 */ __u32 perm; /* 16 4 */ __u32 __reserved; /* 20 4 */ __u64 addr __attribute__((__aligned__(8))); /* 24 8 */ __u32 length; /* 32 4 */ __u32 cookie; /* 36 4 */ /* size: 40, cachelines: 1, members: 9 */ /* forced alignments: 1 */ /* last cacheline: 40 bytes */ } __attribute__((__aligned__(8))); Fixes: c714f15860fc ("iommufd: Add fault and response message definitions") Link: https://patch.msgid.link/r/20250120195051.2450-1-nicolinc@nvidia.com Cc: stable@vger.kernel.org Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-12-03iommu/arm-smmu-v3: Improve uAPI comment for IOMMU_HW_INFO_TYPE_ARM_SMMUV3Jason Gunthorpe
Be specific about what fields should be accessed in the idr result and give other guidance to the VMM on how it should generate the vIDR. Discussion on the list, and review of the qemu implementation understood this needs to be clearer and more detailed. Link: https://patch.msgid.link/r/0-v1-191e5e24cec3+3b0-iommufd_smmuv3_hwinf_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-12-03iommufd: Fix typos in kernel-doc commentsRandy Dunlap
Fix typos/spellos in kernel-doc comments for readability. Fixes: aad37e71d5c4 ("iommufd: IOCTLs for the io_pagetable") Fixes: b7a0855eb95f ("iommu: Add new flag to explictly request PASID capable domain") Fixes: d68beb276ba2 ("iommu/arm-smmu-v3: Support IOMMU_HWPT_INVALIDATE using a VIOMMU object") Link: https://patch.msgid.link/r/20241128035159.374624-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-22Merge tag 'iommu-updates-v6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux Pull iommu updates from Joerg Roedel: "Core Updates: - Convert call-sites using iommu_domain_alloc() to more specific versions and remove function - Introduce iommu_paging_domain_alloc_flags() - Extend support for allocating PASID-capable domains to more drivers - Remove iommu_present() - Some smaller improvements New IOMMU driver for RISC-V Intel VT-d Updates: - Add domain_alloc_paging support - Enable user space IOPFs in non-PASID and non-svm cases - Small code refactoring and cleanups - Add domain replacement support for pasid AMD-Vi Updates: - Adapt to iommu_paging_domain_alloc_flags() interface and alloc V2 page-tables by default - Replace custom domain ID allocator with IDA allocator - Add ops->release_domain() support - Other improvements to device attach and domain allocation code paths ARM-SMMU Updates: - SMMUv2: - Return -EPROBE_DEFER for client devices probing before their SMMU - Devicetree binding updates for Qualcomm MMU-500 implementations - SMMUv3: - Minor fixes and cleanup for NVIDIA's virtual command queue driver - IO-PGTable: - Fix indexing of concatenated PGDs and extend selftest coverage - Remove unused block-splitting support S390 IOMMU: - Implement support for blocking domain Mediatek IOMMU: - Enable 35-bit physical address support for mt8186 OMAP IOMMU driver: - Adapt to recent IOMMU core changes and unbreak driver" * tag 'iommu-updates-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (92 commits) iommu/tegra241-cmdqv: Fix alignment failure at max_n_shift iommu: Make set_dev_pasid op support domain replacement iommu/arm-smmu-v3: Make set_dev_pasid() op support replace iommu/vt-d: Add set_dev_pasid callback for nested domain iommu/vt-d: Make identity_domain_set_dev_pasid() to handle domain replacement iommu/vt-d: Make intel_svm_set_dev_pasid() support domain replacement iommu/vt-d: Limit intel_iommu_set_dev_pasid() for paging domain iommu/vt-d: Make intel_iommu_set_dev_pasid() to handle domain replacement iommu/vt-d: Add iommu_domain_did() to get did iommu/vt-d: Consolidate the struct dev_pasid_info add/remove iommu/vt-d: Add pasid replace helpers iommu/vt-d: Refactor the pasid setup helpers iommu/vt-d: Add a helper to flush cache for updating present pasid entry iommu: Pass old domain to set_dev_pasid op iommu/iova: Fix typo 'adderss' iommu: Add a kdoc to iommu_unmap() iommu/io-pgtable-arm-v7s: Remove split on unmap behavior iommu/io-pgtable-arm: Remove split on unmap behavior iommu/vt-d: Drain PRQs when domain removed from RID iommu/vt-d: Drop pasid requirement for prq initialization ...
2024-11-15Merge branches 'intel/vt-d', 'amd/amd-vi' and 'iommufd/arm-smmuv3-nested' ↵Joerg Roedel
into next
2024-11-14iommufd: Add IOMMU_IOAS_CHANGE_PROCESSSteve Sistare
Add an ioctl that updates all DMA mappings to reflect the current process, Change the mm and transfer locked memory accounting from old to current mm. This will be used for live update, allowing an old process to hand the iommufd device descriptor to a new process. The new process calls the ioctl. IOMMU_IOAS_CHANGE_PROCESS only supports DMA mappings created with IOMMU_IOAS_MAP_FILE, because the kernel metadata for such mappings does not depend on the userland VA of the pages (which is different in the new process). IOMMU_IOAS_CHANGE_PROCESS fails if other types of mappings are present. This is a revised version of code originally provided by Jason. Link: https://patch.msgid.link/r/1731527497-16091-4-git-send-email-steven.sistare@oracle.com Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommu/arm-smmu-v3: Support IOMMU_HWPT_INVALIDATE using a VIOMMU objectNicolin Chen
Implement the vIOMMU's cache_invalidate op for user space to invalidate the IOTLB entries, Device ATS and CD entries that are cached by hardware. Add struct iommu_viommu_arm_smmuv3_invalidate defining invalidation entries that are simply in the native format of a 128-bit TLBI command. Scan those commands against the permitted command list and fix their VMID/SID fields to match what is stored in the vIOMMU. Link: https://patch.msgid.link/r/12-v4-9e99b76f3518+3a8-smmuv3_nesting_jgg@nvidia.com Co-developed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Eric Auger <eric.auger@redhat.com> Co-developed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommu/arm-smmu-v3: Allow ATS for IOMMU_DOMAIN_NESTEDJason Gunthorpe
The EATS flag needs to flow through the vSTE and into the pSTE, and ensure physical ATS is enabled on the PCI device. The physical ATS state must match the VM's idea of EATS as we rely on the VM to issue the ATS invalidation commands. Thus ATS must remain off at the device until EATS on a nesting domain turns it on. Attaching a nesting domain is the point where the invalidation responsibility transfers to userspace. Update the ATS logic to track EATS for nesting domains and flush the ATC whenever the S2 nesting parent changes. Link: https://patch.msgid.link/r/11-v4-9e99b76f3518+3a8-smmuv3_nesting_jgg@nvidia.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTEDJason Gunthorpe
For SMMUv3 a IOMMU_DOMAIN_NESTED is composed of a S2 iommu_domain acting as the parent and a user provided STE fragment that defines the CD table and related data with addresses translated by the S2 iommu_domain. The kernel only permits userspace to control certain allowed bits of the STE that are safe for user/guest control. IOTLB maintenance is a bit subtle here, the S1 implicitly includes the S2 translation, but there is no way of knowing which S1 entries refer to a range of S2. For the IOTLB we follow ARM's guidance and issue a CMDQ_OP_TLBI_NH_ALL to flush all ASIDs from the VMID after flushing the S2 on any change to the S2. The IOMMU_DOMAIN_NESTED can only be created from inside a VIOMMU as the invalidation path relies on the VIOMMU to translate virtual stream ID used in the invalidation commands for the CD table and ATS. Link: https://patch.msgid.link/r/9-v4-9e99b76f3518+3a8-smmuv3_nesting_jgg@nvidia.com Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Reviewed-by: Donald Dutile <ddutile@redhat.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommu/arm-smmu-v3: Support IOMMU_VIOMMU_ALLOCNicolin Chen
Add a new driver-type for ARM SMMUv3 to enum iommu_viommu_type. Implement an arm_vsmmu_alloc(). As an initial step, copy the VMID from s2_parent. A followup series is required to give the VIOMMU object it's own VMID that will be used in all nesting configurations. Link: https://patch.msgid.link/r/8-v4-9e99b76f3518+3a8-smmuv3_nesting_jgg@nvidia.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12Merge branch 'iommufd/arm-smmuv3-nested' of iommu/linux into iommufd for-nextJason Gunthorpe
Common SMMUv3 patches for the following patches adding nesting, shared branch with the iommu tree. * 'iommufd/arm-smmuv3-nested' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/iommu/linux: iommu/arm-smmu-v3: Expose the arm_smmu_attach interface iommu/arm-smmu-v3: Implement IOMMU_HWPT_ALLOC_NEST_PARENT iommu/arm-smmu-v3: Support IOMMU_GET_HW_INFO via struct arm_smmu_hw_info iommu/arm-smmu-v3: Report IOMMU_CAP_ENFORCE_CACHE_COHERENCY for CANWBS ACPI/IORT: Support CANWBS memory access flag ACPICA: IORT: Update for revision E.f vfio: Remove VFIO_TYPE1_NESTING_IOMMU ... Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATENicolin Chen
With a vIOMMU object, use space can flush any IOMMU related cache that can be directed via a vIOMMU object. It is similar to the IOMMU_HWPT_INVALIDATE uAPI, but can cover a wider range than IOTLB, e.g. device/desciprtor cache. Allow hwpt_id of the iommu_hwpt_invalidate structure to carry a viommu_id, and reuse the IOMMU_HWPT_INVALIDATE uAPI for vIOMMU invalidations. Drivers can define different structures for vIOMMU invalidations v.s. HWPT ones. Since both the HWPT-based and vIOMMU-based invalidation pathways check own cache invalidation op, remove the WARN_ON_ONCE in the allocator. Update the uAPI, kdoc, and selftest case accordingly. Link: https://patch.msgid.link/r/b411e2245e303b8a964f39f49453a5dff280968f.1730836308.git.nicolinc@nvidia.com Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommufd/viommu: Add IOMMUFD_OBJ_VDEVICE and IOMMU_VDEVICE_ALLOC ioctlNicolin Chen
Introduce a new IOMMUFD_OBJ_VDEVICE to represent a physical device (struct device) against a vIOMMU (struct iommufd_viommu) object in a VM. This vDEVICE object (and its structure) holds all the infos and attributes in the VM, regarding the device related to the vIOMMU. As an initial patch, add a per-vIOMMU virtual ID. This can be: - Virtual StreamID on a nested ARM SMMUv3, an index to a Stream Table - Virtual DeviceID on a nested AMD IOMMU, an index to a Device Table - Virtual RID on a nested Intel VT-D IOMMU, an index to a Context Table Potentially, this vDEVICE structure would hold some vData for Confidential Compute Architecture (CCA). Use this virtual ID to index an "vdevs" xarray that belongs to a vIOMMU object. Add a new ioctl for vDEVICE allocations. Since a vDEVICE is a connection of a device object and an iommufd_viommu object, take two refcounts in the ioctl handler. Link: https://patch.msgid.link/r/cda8fd2263166e61b8191a3b3207e0d2b08545bf.1730836308.git.nicolinc@nvidia.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommufd: Allow pt_id to carry viommu_id for IOMMU_HWPT_ALLOCNicolin Chen
Now a vIOMMU holds a shareable nesting parent HWPT. So, it can act like that nesting parent HWPT to allocate a nested HWPT. Support that in the IOMMU_HWPT_ALLOC ioctl handler, and update its kdoc. Also, add an iommufd_viommu_alloc_hwpt_nested helper to allocate a nested HWPT for a vIOMMU object. Since a vIOMMU object holds the parent hwpt's refcount already, increase the refcount of the vIOMMU only. Link: https://patch.msgid.link/r/a0f24f32bfada8b448d17587adcaedeeb50a67ed.1730836219.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-12iommufd/viommu: Add IOMMU_VIOMMU_ALLOC ioctlNicolin Chen
Add a new ioctl for user space to do a vIOMMU allocation. It must be based on a nesting parent HWPT, so take its refcount. IOMMU driver wanting to support vIOMMUs must define its IOMMU_VIOMMU_TYPE_ in the uAPI header and implement a viommu_alloc op in its iommu_ops. Link: https://patch.msgid.link/r/dc2b8ba9ac935007beff07c1761c31cd097ed780.1730836219.git.nicolinc@nvidia.com Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-11-05iommu/arm-smmu-v3: Support IOMMU_GET_HW_INFO via struct arm_smmu_hw_infoNicolin Chen
For virtualization cases the IDR/IIDR/AIDR values of the actual SMMU instance need to be available to the VMM so it can construct an appropriate vSMMUv3 that reflects the correct HW capabilities. For userspace page tables these values are required to constrain the valid values within the CD table and the IOPTEs. The kernel does not sanitize these values. If building a VMM then userspace is required to only forward bits into a VM that it knows it can implement. Some bits will also require a VMM to detect if appropriate kernel support is available such as for ATS and BTM. Start a new file and kconfig for the advanced iommufd support. This lets it be compiled out for kernels that are not intended to support virtualization, and allows distros to leave it disabled until they are shipping a matching qemu too. Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Reviewed-by: Donald Dutile <ddutile@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/5-v4-9e99b76f3518+3a8-smmuv3_nesting_jgg@nvidia.com Signed-off-by: Will Deacon <will@kernel.org>
2024-10-29iommu: Add new flag to explictly request PASID capable domainJason Gunthorpe
Introduce new flag (IOMMU_HWPT_ALLOC_PASID) to domain_alloc_users() ops. If IOMMU supports PASID it will allocate domain. Otherwise return error. In error path check for -EOPNOTSUPP and try to allocate non-PASID domain so that DMA-API mode work fine for drivers which does not support PASID as well. Also modify __iommu_group_alloc_default_domain() to call iommu_paging_domain_alloc_flags() with appropriate flag when allocating paging domain. Signed-off-by: Jason Gunthorpe <jgg@ziepe.ca> Co-developed-by: Vasant Hegde <vasant.hegde@amd.com> Signed-off-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20241028093810.5901-4-vasant.hegde@amd.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2024-10-28iommufd: Add IOMMU_IOAS_MAP_FILESteve Sistare
Define the IOMMU_IOAS_MAP_FILE ioctl interface, which allows a user to register memory by passing a memfd plus offset and length. Implement it using the memfd_pin_folios() kAPI. Link: https://patch.msgid.link/r/1729861919-234514-8-git-send-email-steven.sistare@oracle.com Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-08-26iommufd: Reorder include filesNicolin Chen
Reorder include files to alphabetic order to simplify maintenance, and separate local headers and global headers with a blank line. No functional change intended. Link: https://patch.msgid.link/r/7524b037cc05afe19db3c18f863253e1d1554fa2.1722644866.git.nicolinc@nvidia.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-07-15iommufd: Put constants for all the uAPI enumsJason Gunthorpe
Relying on position in the enum makes it subtly harder when doing merge resolutions or backporting as it is easy to grab a patch and not notice it is a uAPI change with a differently ordered enum. This may become a bigger problem in next cycles when iommu_hwpt_invalidate_data_type and other per-driver enums have patches flowing through different trees. So lets start including constants for all the uAPI enums to make this safer. No functional change. Link: https://lore.kernel.org/r/0-v1-2c06ec044924+133-iommufd_uapi_const_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-07-11iommufd: Remove IOMMUFD_PAGE_RESP_FAILURELu Baolu
The response code of IOMMUFD_PAGE_RESP_FAILURE was defined to be equivalent to the "Response Failure" in PCI spec, section 10.4.2.1. This response code indicates that one or more pages within the associated request group have encountered or caused an unrecoverable error. Therefore, this response disables the PRI at the function. Modern I/O virtualization technologies, like SR-IOV, share PRI among the assignable device units. Therefore, a response failure on one unit might cause I/O failure on other units. Remove this response code so that user space can only respond with SUCCESS or INVALID. The VMM is recommended to emulate a failure response as a PRI reset, or PRI disable and changing to a non-PRI domain. Fixes: c714f15860fc ("iommufd: Add fault and response message definitions") Link: https://lore.kernel.org/r/20240710083341.44617-2-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-07-09iommufd: Associate fault object with iommufd_hw_pgtableLu Baolu
When allocating a user iommufd_hw_pagetable, the user space is allowed to associate a fault object with the hw_pagetable by specifying the fault object ID in the page table allocation data and setting the IOMMU_HWPT_FAULT_ID_VALID flag bit. On a successful return of hwpt allocation, the user can retrieve and respond to page faults by reading and writing the file interface of the fault object. Once a fault object has been associated with a hwpt, the hwpt is iopf-capable, indicated by hwpt->fault is non NULL. Attaching, detaching, or replacing an iopf-capable hwpt to an RID or PASID will differ from those that are not iopf-capable. Link: https://lore.kernel.org/r/20240702063444.105814-9-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-07-09iommufd: Add iommufd fault objectLu Baolu
An iommufd fault object provides an interface for delivering I/O page faults to user space. These objects are created and destroyed by user space, and they can be associated with or dissociated from hardware page table objects during page table allocation or destruction. User space interacts with the fault object through a file interface. This interface offers a straightforward and efficient way for user space to handle page faults. It allows user space to read fault messages sequentially and respond to them by writing to the same file. The file interface supports reading messages in poll mode, so it's recommended that user space applications use io_uring to enhance read and write efficiency. A fault object can be associated with any iopf-capable iommufd_hw_pgtable during the pgtable's allocation. All I/O page faults triggered by devices when accessing the I/O addresses of an iommufd_hw_pgtable are routed through the fault object to user space. Similarly, user space's responses to these page faults are routed back to the iommu device driver through the same fault object. Link: https://lore.kernel.org/r/20240702063444.105814-7-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-07-09iommufd: Add fault and response message definitionsLu Baolu
iommu_hwpt_pgfaults represent fault messages that the userspace can retrieve. Multiple iommu_hwpt_pgfaults might be put in an iopf group, with the IOMMU_PGFAULT_FLAGS_LAST_PAGE flag set only for the last iommu_hwpt_pgfault. An iommu_hwpt_page_response is a response message that the userspace should send to the kernel after finishing handling a group of fault messages. The @dev_id, @pasid, and @grpid fields in the message identify an outstanding iopf group for a device. The @cookie field, which matches the cookie field of the last fault in the group, will be used by the kernel to look up the pending message. Link: https://lore.kernel.org/r/20240702063444.105814-6-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-01-11iommufd: Add data structure for Intel VT-d stage-1 cache invalidationYi Liu
This adds the data structure invalidating caches for the nested domain allocated with IOMMU_HWPT_DATA_VTD_S1 type. Link: https://lore.kernel.org/r/20240111041015.47920-8-yi.l.liu@intel.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-01-11iommufd: Add IOMMU_HWPT_INVALIDATEYi Liu
In nested translation, the stage-1 page table is user-managed but cached by the IOMMU hardware, so an update on present page table entries in the stage-1 page table should be followed with a cache invalidation. Add an IOMMU_HWPT_INVALIDATE ioctl to support such a cache invalidation. It takes hwpt_id to specify the iommu_domain, and a multi-entry array to support multiple invalidation data in one ioctl. enum iommu_hwpt_invalidate_data_type is defined to tag the data type of the entries in the multi-entry array. Link: https://lore.kernel.org/r/20240111041015.47920-3-yi.l.liu@intel.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Co-developed-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26iommu/vt-d: Disallow read-only mappings to nest parent domainLu Baolu
When remapping hardware is configured by system software in scalable mode as Nested (PGTT=011b) and with PWSNP field Set in the PASID-table-entry, it may Set Accessed bit and Dirty bit (and Extended Access bit if enabled) in first-stage page-table entries even when second-stage mappings indicate that corresponding first-stage page-table is Read-Only. As the result, contents of pages designated by VMM as Read-Only can be modified by IOMMU via PML5E (PML4E for 4-level tables) access as part of address translation process due to DMAs issued by Guest. This disallows read-only mappings in the domain that is supposed to be used as nested parent. Reference from Sapphire Rapids Specification Update [1], errata details, SPR17. Userspace should know this limitation by checking the IOMMU_HW_INFO_VTD_ERRATA_772415_SPR17 flag reported in the IOMMU_GET_HW_INFO ioctl. [1] https://www.intel.com/content/www/us/en/content-details/772415/content-details.html Link: https://lore.kernel.org/r/20231026044216.64964-9-yi.l.liu@intel.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26iommufd: Add data structure for Intel VT-d stage-1 domain allocationYi Liu
This adds IOMMU_HWPT_DATA_VTD_S1 for stage-1 hw_pagetable of Intel VT-d and the corressponding data structure for userspace specified parameter for the domain allocation. Link: https://lore.kernel.org/r/20231026044216.64964-2-yi.l.liu@intel.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26iommufd: Add a nested HW pagetable objectNicolin Chen
IOMMU_HWPT_ALLOC already supports iommu_domain allocation for usersapce. But it can only allocate a hw_pagetable that associates to a given IOAS, i.e. only a kernel-managed hw_pagetable of IOMMUFD_OBJ_HWPT_PAGING type. IOMMU drivers can now support user-managed hw_pagetables, for two-stage translation use cases that require user data input from the user space. Add a new IOMMUFD_OBJ_HWPT_NESTED type with its abort/destroy(). Pair it with a new iommufd_hwpt_nested structure and its to_hwpt_nested() helper. Update the to_hwpt_paging() helper, so a NESTED-type hw_pagetable can be handled in the callers, for example iommufd_hw_pagetable_enforce_rr(). Screen the inputs including the parent PAGING-type hw_pagetable that has a need of a new nest_parent flag in the iommufd_hwpt_paging structure. Extend the IOMMU_HWPT_ALLOC ioctl to accept an IOMMU driver specific data input which is tagged by the enum iommu_hwpt_data_type. Also, update the @pt_id to accept hwpt_id too besides an ioas_id. Then, use them to allocate a hw_pagetable of IOMMUFD_OBJ_HWPT_NESTED type using the iommufd_hw_pagetable_alloc_nested() allocator. Link: https://lore.kernel.org/r/20231026043938.63898-8-yi.l.liu@intel.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Co-developed-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24iommufd: Add a flag to skip clearing of IOPTE dirtyJoao Martins
VFIO has an operation where it unmaps an IOVA while returning a bitmap with the dirty data. In reality the operation doesn't quite query the IO pagetables that the PTE was dirty or not. Instead it marks as dirty on anything that was mapped, and doing so in one syscall. In IOMMUFD the equivalent is done in two operations by querying with GET_DIRTY_IOVA followed by UNMAP_IOVA. However, this would incur two TLB flushes given that after clearing dirty bits IOMMU implementations require invalidating their IOTLB, plus another invalidation needed for the UNMAP. To allow dirty bits to be queried faster, add a flag (IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR) that requests to not clear the dirty bits from the PTE (but just reading them), under the expectation that the next operation is the unmap. An alternative is to unmap and just perpectually mark as dirty as that's the same behaviour as today. So here equivalent functionally can be provided with unmap alone, and if real dirty info is required it will amortize the cost while querying. There's still a race against DMA where in theory the unmap of the IOVA (when the guest invalidates the IOTLB via emulated iommu) would race against the VF performing DMA on the same IOVA. As discussed in [0], we are accepting to resolve this race as throwing away the DMA and it doesn't matter if it hit physical DRAM or not, the VM can't tell if we threw it away because the DMA was blocked or because we failed to copy the DRAM. [0] https://lore.kernel.org/linux-iommu/20220502185239.GR8364@nvidia.com/ Link: https://lore.kernel.org/r/20231024135109.73787-10-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24iommufd: Add capabilities to IOMMU_GET_HW_INFOJoao Martins
Extend IOMMUFD_CMD_GET_HW_INFO op to query generic iommu capabilities for a given device. Capabilities are IOMMU agnostic and use device_iommu_capable() API passing one of the IOMMU_CAP_*. Enumerate IOMMU_CAP_DIRTY_TRACKING for now in the out_capabilities field returned back to userspace. Link: https://lore.kernel.org/r/20231024135109.73787-9-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAPJoao Martins
Connect a hw_pagetable to the IOMMU core dirty tracking read_and_clear_dirty iommu domain op. It exposes all of the functionality for the UAPI that read the dirtied IOVAs while clearing the Dirty bits from the PTEs. In doing so, add an IO pagetable API iopt_read_and_clear_dirty_data() that performs the reading of dirty IOPTEs for a given IOVA range and then copying back to userspace bitmap. Underneath it uses the IOMMU domain kernel API which will read the dirty bits, as well as atomically clearing the IOPTE dirty bit and flushing the IOTLB at the end. The IOVA bitmaps usage takes care of the iteration of the bitmaps user pages efficiently and without copies. Within the iterator function we iterate over io-pagetable contigous areas that have been mapped. Contrary to past incantation of a similar interface in VFIO the IOVA range to be scanned is tied in to the bitmap size, thus the application needs to pass a appropriately sized bitmap address taking into account the iova range being passed *and* page size ... as opposed to allowing bitmap-iova != iova. Link: https://lore.kernel.org/r/20231024135109.73787-8-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKINGJoao Martins
Every IOMMU driver should be able to implement the needed iommu domain ops to control dirty tracking. Connect a hw_pagetable to the IOMMU core dirty tracking ops, specifically the ability to enable/disable dirty tracking on an IOMMU domain (hw_pagetable id). To that end add an io_pagetable kernel API to toggle dirty tracking: * iopt_set_dirty_tracking(iopt, [domain], state) The intended caller of this is via the hw_pagetable object that is created. Internally it will ensure the leftover dirty state is cleared /right before/ dirty tracking starts. This is also useful for iommu drivers which may decide that dirty tracking is always-enabled at boot without wanting to toggle dynamically via corresponding iommu domain op. Link: https://lore.kernel.org/r/20231024135109.73787-7-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24iommufd: Add a flag to enforce dirty tracking on attachJoao Martins
Throughout IOMMU domain lifetime that wants to use dirty tracking, some guarantees are needed such that any device attached to the iommu_domain supports dirty tracking. The idea is to handle a case where IOMMU in the system are assymetric feature-wise and thus the capability may not be supported for all devices. The enforcement is done by adding a flag into HWPT_ALLOC namely: IOMMU_HWPT_ALLOC_DIRTY_TRACKING .. Passed in HWPT_ALLOC ioctl() flags. The enforcement is done by creating a iommu_domain via domain_alloc_user() and validating the requested flags with what the device IOMMU supports (and failing accordingly) advertised). Advertising the new IOMMU domain feature flag requires that the individual iommu driver capability is supported when a future device attachment happens. Link: https://lore.kernel.org/r/20231024135109.73787-6-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-21iommufd: Correct IOMMU_HWPT_ALLOC_NEST_PARENT descriptionNicolin Chen
The IOMMU_HWPT_ALLOC_NEST_PARENT flag is used to allocate a HWPT. Though a HWPT holds a domain in the core structure, it is still quite confusing to describe it using "domain" in the uAPI kdoc. Correct it to "HWPT". Fixes: 4ff542163397 ("iommufd: Support allocating nested parent domain") Link: https://lore.kernel.org/r/20231017181552.12667-1-nicolinc@nvidia.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10iommufd: Support allocating nested parent domainYi Liu
Extend IOMMU_HWPT_ALLOC to allocate domains to be used as parent (stage-2) in nested translation. Add IOMMU_HWPT_ALLOC_NEST_PARENT to the uAPI. Link: https://lore.kernel.org/r/20230928071528.26258-5-yi.l.liu@intel.com Signed-off-by: Yi Liu <yi.l.liu@intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>