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path: root/include/linux/iommufd.h
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2024-11-12iommufd/viommu: Add iommufd_viommu_find_dev helperNicolin Chen
This avoids a bigger trouble of exposing struct iommufd_device and struct iommufd_vdevice in the public header. Link: https://patch.msgid.link/r/84fa7c624db4d4508067ccfdf42059533950180a.1730836308.git.nicolinc@nvidia.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>
2024-11-12iommu/viommu: Add cache_invalidate to iommufd_viommu_opsNicolin Chen
This per-vIOMMU cache_invalidate op is like the cache_invalidate_user op in struct iommu_domain_ops, but wider, supporting device cache (e.g. PCI ATC invaldiations). Link: https://patch.msgid.link/r/90138505850fa6b165135e78a87b4cc7022869a4.1730836308.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: Add alloc_domain_nested op to iommufd_viommu_opsNicolin Chen
Allow IOMMU driver to use a vIOMMU object that holds a nesting parent hwpt/domain to allocate a nested domain. Link: https://patch.msgid.link/r/2dcdb5e405dc0deb68230564530d989d285d959c.1730836219.git.nicolinc@nvidia.com Suggested-by: Jason Gunthorpe <jgg@nvidia.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>
2024-11-12iommufd: Introduce IOMMUFD_OBJ_VIOMMU and its related structNicolin Chen
Add a new IOMMUFD_OBJ_VIOMMU with an iommufd_viommu structure to represent a slice of physical IOMMU device passed to or shared with a user space VM. This slice, now a vIOMMU object, is a group of virtualization resources of a physical IOMMU's, such as: - Security namespace for guest owned ID, e.g. guest-controlled cache tags - Non-device-affiliated event reporting, e.g. invalidation queue errors - Access to a sharable nesting parent pagetable across physical IOMMUs - Virtualization of various platforms IDs, e.g. RIDs and others - Delivery of paravirtualized invalidation - Direct assigned invalidation queues - Direct assigned interrupts Add a new viommu_alloc op in iommu_ops, for drivers to allocate their own vIOMMU structures. And this allocation also needs a free(), so add struct iommufd_viommu_ops. To simplify a vIOMMU allocation, provide a iommufd_viommu_alloc() helper. It's suggested that a driver should embed a core-level viommu structure in its driver-level viommu struct and call the iommufd_viommu_alloc() helper, meanwhile the driver can also implement a viommu ops: struct my_driver_viommu { struct iommufd_viommu core; /* driver-owned properties/features */ .... }; static const struct iommufd_viommu_ops my_driver_viommu_ops = { .free = my_driver_viommu_free, /* future ops for virtualization features */ .... }; static struct iommufd_viommu my_driver_viommu_alloc(...) { struct my_driver_viommu *my_viommu = iommufd_viommu_alloc(ictx, my_driver_viommu, core, my_driver_viommu_ops); /* Init my_viommu and related HW feature */ .... return &my_viommu->core; } static struct iommu_domain_ops my_driver_domain_ops = { .... .viommu_alloc = my_driver_viommu_alloc, }; Link: https://patch.msgid.link/r/64685e2b79dea0f1dc56f6ede04809b72d578935.1730836219.git.nicolinc@nvidia.com Suggested-by: Jason Gunthorpe <jgg@nvidia.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>
2024-11-12iommufd: Move _iommufd_object_alloc helper to a sharable fileNicolin Chen
The following patch will add a new vIOMMU allocator that will require this _iommufd_object_alloc to be sharable with IOMMU drivers (and iommufd too). Add a new driver.c file that will be built with CONFIG_IOMMUFD_DRIVER_CORE selected by CONFIG_IOMMUFD, and put the CONFIG_DRIVER under that remaining to be selectable for drivers to build the existing iova_bitmap.c file. Link: https://patch.msgid.link/r/2f4f6e116dc49ffb67ff6c5e8a7a8e789ab9e98e.1730836219.git.nicolinc@nvidia.com Suggested-by: Jason Gunthorpe <jgg@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>
2024-11-08iommufd: Move struct iommufd_object to public iommufd headerNicolin Chen
Prepare for an embedded structure design for driver-level iommufd_viommu objects: // include/linux/iommufd.h struct iommufd_viommu { struct iommufd_object obj; .... }; // Some IOMMU driver struct iommu_driver_viommu { struct iommufd_viommu core; .... }; It has to expose struct iommufd_object and enum iommufd_object_type from the core-level private header to the public iommufd header. Link: https://patch.msgid.link/r/54a43b0768089d690104530754f499ca05ce0074.1730836219.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>
2024-09-05iommufd: Reorder struct forward declarationsNicolin Chen
Reorder struct forward declarations to alphabetic order to simplify maintenance, as upcoming patches will add more to the list. No functional change intended. Link: https://patch.msgid.link/r/c5dd87100f6f01389b838c63237e28c5dd373358.1724776335.git.nicolinc@nvidia.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.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>
2023-07-28iommufd: Add iommufd_access_replace() APINicolin Chen
Taking advantage of the new iommufd_access_change_ioas_id helper, add an iommufd_access_replace() API for the VFIO emulated pathway to use. Link: https://lore.kernel.org/r/a3267b924fd5f45e0d3a1dd13a9237e923563862.1690523699.git.nicolinc@nvidia.com Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26iommufd/selftest: Test iommufd_device_replace()Nicolin Chen
Allow the selftest to call the function on the mock idev, add some tests to exercise it. Link: https://lore.kernel.org/r/16-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-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>
2023-07-25iommufd: Add iommufd_ctx_from_fd()Yi Liu
It's common to get a reference to the iommufd context from a given file descriptor. So adds an API for it. Existing users of this API are compiled only when IOMMUFD is enabled, so no need to have a stub for the IOMMUFD disabled case. Tested-by: Yanting Jiang <yanting.jiang@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20230718135551.6592-21-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25iommufd/device: Add iommufd_access_detach() APINicolin Chen
Previously, the detach routine is only done by the destroy(). And it was called by vfio_iommufd_emulated_unbind() when the device runs close(), so all the mappings in iopt were cleaned in that setup, when the call trace reaches this detach() routine. Now, there's a need of a detach uAPI, meaning that it does not only need a new iommufd_access_detach() API, but also requires access->ops->unmap() call as a cleanup. So add one. However, leaving that unprotected can introduce some potential of a race condition during the pin_/unpin_pages() call, where access->ioas->iopt is getting referenced. So, add an ioas_lock to protect the context of iopt referencings. Also, to allow the iommufd_access_unpin_pages() callback to happen via this unmap() call, add an ioas_unpin pointer, so the unpin routine won't be affected by the "access->ioas = NULL" trick. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Yanting Jiang <yanting.jiang@intel.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20230718135551.6592-15-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25iommufd: Add helper to retrieve iommufd_ctx and devidYi Liu
This is needed by the vfio-pci driver to report affected devices in the hot-reset for a given device. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Yanting Jiang <yanting.jiang@intel.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20230718105542.4138-6-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25iommufd: Add iommufd_ctx_has_group()Yi Liu
This adds the helper to check if any device within the given iommu_group has been bound with the iommufd_ctx. This is helpful for the checking on device ownership for the devices which have not been bound but cannot be bound to any other iommufd_ctx as the iommu_group has been bound. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Yanting Jiang <yanting.jiang@intel.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20230718105542.4138-5-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-03-31vfio-iommufd: Make vfio_iommufd_emulated_bind() return iommufd_access IDYi Liu
vfio device cdev needs to return iommufd_access ID to userspace if bind_iommufd succeeds. Link: https://lore.kernel.org/r/20230327093351.44505-5-yi.l.liu@intel.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-31iommufd: Create access in vfio_iommufd_emulated_bind()Nicolin Chen
There are needs to created iommufd_access prior to have an IOAS and set IOAS later. Like the vfio device cdev needs to have an iommufd object to represent the bond (iommufd_access) and IOAS replacement. Moves the iommufd_access_create() call into vfio_iommufd_emulated_bind(), making it symmetric with the __vfio_iommufd_access_destroy() call in the vfio_iommufd_emulated_unbind(). This means an access is created/destroyed by the bind()/unbind(), and the vfio_iommufd_emulated_attach_ioas() only updates the access->ioas pointer. Since vfio_iommufd_emulated_bind() does not provide ioas_id, drop it from the argument list of iommufd_access_create(). Instead, add a new access API iommufd_access_attach() to set the access->ioas pointer. Also, set vdev->iommufd_attached accordingly, similar to the physical pathway. Link: https://lore.kernel.org/r/20230327093351.44505-3-yi.l.liu@intel.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-02-03vfio: Support VFIO_NOIOMMU with iommufdJason Gunthorpe
Add a small amount of emulation to vfio_compat to accept the SET_IOMMU to VFIO_NOIOMMU_IOMMU and have vfio just ignore iommufd if it is working on a no-iommu enabled device. Move the enable_unsafe_noiommu_mode module out of container.c into vfio_main.c so that it is always available even if VFIO_CONTAINER=n. This passes Alex's mini-test: https://github.com/awilliam/tests/blob/master/vfio-noiommu-pci-device-open.c Link: https://lore.kernel.org/r/0-v3-480cd64a16f7+1ad0-iommufd_noiommu_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30iommufd: Add kernel support for testing iommufdJason Gunthorpe
Provide a mock kernel module for the iommu_domain that allows it to run without any HW and the mocking provides a way to directly validate that the PFNs loaded into the iommu_domain are correct. This exposes the access kAPI toward userspace to allow userspace to explore the functionality of pages.c and io_pagetable.c The mock also simulates the rare case of PAGE_SIZE > iommu page size as the mock will operate at a 2K iommu page size. This allows exercising all of the calculations to support this mismatch. This is also intended to support syzkaller exploring the same space. However, it is an unusually invasive config option to enable all of this. The config option should not be enabled in a production kernel. Link: https://lore.kernel.org/r/16-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390 Tested-by: Eric Auger <eric.auger@redhat.com> # aarch64 Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30iommufd: vfio container FD ioctl compatibilityJason Gunthorpe
iommufd can directly implement the /dev/vfio/vfio container IOCTLs by mapping them into io_pagetable operations. A userspace application can test against iommufd and confirm compatibility then simply make a small change to open /dev/iommu instead of /dev/vfio/vfio. For testing purposes /dev/vfio/vfio can be symlinked to /dev/iommu and then all applications will use the compatibility path with no code changes. A later series allows /dev/vfio/vfio to be directly provided by iommufd, which allows the rlimit mode to work the same as well. This series just provides the iommufd side of compatibility. Actually linking this to VFIO_SET_CONTAINER is a followup series, with a link in the cover letter. Internally the compatibility API uses a normal IOAS object that, like vfio, is automatically allocated when the first device is attached. Userspace can also query or set this IOAS object directly using the IOMMU_VFIO_IOAS ioctl. This allows mixing and matching new iommufd only features while still using the VFIO style map/unmap ioctls. While this is enough to operate qemu, it has a few differences: - Resource limits rely on memory cgroups to bound what userspace can do instead of the module parameter dma_entry_limit. - VFIO P2P is not implemented. The DMABUF patches for vfio are a start at a solution where iommufd would import a special DMABUF. This is to avoid further propogating the follow_pfn() security problem. - A full audit for pedantic compatibility details (eg errnos, etc) has not yet been done - powerpc SPAPR is left out, as it is not connected to the iommu_domain framework. It seems interest in SPAPR is minimal as it is currently non-working in v6.1-rc1. They will have to convert to the iommu subsystem framework to enjoy iommfd. The following are not going to be implemented and we expect to remove them from VFIO type1: - SW access 'dirty tracking'. As discussed in the cover letter this will be done in VFIO. - VFIO_TYPE1_NESTING_IOMMU https://lore.kernel.org/all/0-v1-0093c9b0e345+19-vfio_no_nesting_jgg@nvidia.com/ - VFIO_DMA_MAP_FLAG_VADDR https://lore.kernel.org/all/Yz777bJZjTyLrHEQ@nvidia.com/ Link: https://lore.kernel.org/r/15-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Lixiao Yang <lixiao.yang@intel.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30iommufd: Add kAPI toward external drivers for kernel accessJason Gunthorpe
Kernel access is the mode that VFIO "mdevs" use. In this case there is no struct device and no IOMMU connection. iommufd acts as a record keeper for accesses and returns the actual struct pages back to the caller to use however they need. eg with kmap or the DMA API. Each caller must create a struct iommufd_access with iommufd_access_create(), similar to how iommufd_device_bind() works. Using this struct the caller can access blocks of IOVA using iommufd_access_pin_pages() or iommufd_access_rw(). Callers must provide a callback that immediately unpins any IOVA being used within a range. This happens if userspace unmaps the IOVA under the pin. The implementation forwards the access requests directly to the iopt infrastructure that manages the iopt_pages_access. Link: https://lore.kernel.org/r/14-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Lixiao Yang <lixiao.yang@intel.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30iommufd: Add kAPI toward external drivers for physical devicesJason Gunthorpe
Add the four functions external drivers need to connect physical DMA to the IOMMUFD: iommufd_device_bind() / iommufd_device_unbind() Register the device with iommufd and establish security isolation. iommufd_device_attach() / iommufd_device_detach() Connect a bound device to a page table Binding a device creates a device object ID in the uAPI, however the generic API does not yet provide any IOCTLs to manipulate them. Link: https://lore.kernel.org/r/13-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Lixiao Yang <lixiao.yang@intel.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30iommufd: PFN handling for iopt_pagesJason Gunthorpe
The top of the data structure provides an IO Address Space (IOAS) that is similar to a VFIO container. The IOAS allows map/unmap of memory into ranges of IOVA called iopt_areas. Multiple IOMMU domains (IO page tables) and in-kernel accesses (like VFIO mdevs) can be attached to the IOAS to access the PFNs that those IOVA areas cover. The IO Address Space (IOAS) datastructure is composed of: - struct io_pagetable holding the IOVA map - struct iopt_areas representing populated portions of IOVA - struct iopt_pages representing the storage of PFNs - struct iommu_domain representing each IO page table in the system IOMMU - struct iopt_pages_access representing in-kernel accesses of PFNs (ie VFIO mdevs) - struct xarray pinned_pfns holding a list of pages pinned by in-kernel accesses This patch introduces the lowest part of the datastructure - the movement of PFNs in a tiered storage scheme: 1) iopt_pages::pinned_pfns xarray 2) Multiple iommu_domains 3) The origin of the PFNs, i.e. the userspace pointer PFN have to be copied between all combinations of tiers, depending on the configuration. The interface is an iterator called a 'pfn_reader' which determines which tier each PFN is stored and loads it into a list of PFNs held in a struct pfn_batch. Each step of the iterator will fill up the pfn_batch, then the caller can use the pfn_batch to send the PFNs to the required destination. Repeating this loop will read all the PFNs in an IOVA range. The pfn_reader and pfn_batch also keep track of the pinned page accounting. While PFNs are always stored and accessed as full PAGE_SIZE units the iommu_domain tier can store with a sub-page offset/length to support IOMMUs with a smaller IOPTE size than PAGE_SIZE. Link: https://lore.kernel.org/r/8-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Lixiao Yang <lixiao.yang@intel.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30iommufd: File descriptor, context, kconfig and makefilesJason Gunthorpe
This is the basic infrastructure of a new miscdevice to hold the iommufd IOCTL API. It provides: - A miscdevice to create file descriptors to run the IOCTL interface over - A table based ioctl dispatch and centralized extendable pre-validation step - An xarray mapping userspace ID's to kernel objects. The design has multiple inter-related objects held within in a single IOMMUFD fd - A simple usage count to build a graph of object relations and protect against hostile userspace racing ioctls The only IOCTL provided in this patch is the generic 'destroy any object by handle' operation. Link: https://lore.kernel.org/r/6-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Lixiao Yang <lixiao.yang@intel.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>