kernel/linux.git/include/linux/iommu.h, branch linux-5.8.y

Merge tag 'iommu-updates-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2020-06-08T18:42:23+00:00

Pull iommu updates from Joerg Roedel: "A big part of this is a change in how devices get connected to IOMMUs in the core code. It contains the change from the old add_device() / remove_device() to the new probe_device() / release_device() call-backs. As a result functionality that was previously in the IOMMU drivers has been moved to the IOMMU core code, including IOMMU group allocation for each device. The reason for this change was to get more robust allocation of default domains for the iommu groups. A couple of fixes were necessary after this was merged into the IOMMU tree, but there are no known bugs left. The last fix is applied on-top of the merge commit for the topic branches. Other than that change, we have: - Removal of the driver private domain handling in the Intel VT-d driver. This was fragile code and I am glad it is gone now. - More Intel VT-d updates from Lu Baolu: - Nested Shared Virtual Addressing (SVA) support to the Intel VT-d driver - Replacement of the Intel SVM interfaces to the common IOMMU SVA API - SVA Page Request draining support - ARM-SMMU Updates from Will: - Avoid mapping reserved MMIO space on SMMUv3, so that it can be claimed by the PMU driver - Use xarray to manage ASIDs on SMMUv3 - Reword confusing shutdown message - DT compatible string updates - Allow implementations to override the default domain type - A new IOMMU driver for the Allwinner Sun50i platform - Support for ATS gets disabled for untrusted devices (like Thunderbolt devices). This includes a PCI patch, acked by Bjorn. - Some cleanups to the AMD IOMMU driver to make more use of IOMMU core features. - Unification of some printk formats in the Intel and AMD IOMMU drivers and in the IOVA code. - Updates for DT bindings - A number of smaller fixes and cleanups. * tag 'iommu-updates-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (109 commits) iommu: Check for deferred attach in iommu_group_do_dma_attach() iommu/amd: Remove redundant devid checks iommu/amd: Store dev_data as device iommu private data iommu/amd: Merge private header files iommu/amd: Remove PD_DMA_OPS_MASK iommu/amd: Consolidate domain allocation/freeing iommu/amd: Free page-table in protection_domain_free() iommu/amd: Allocate page-table in protection_domain_init() iommu/amd: Let free_pagetable() not rely on domain->pt_root iommu/amd: Unexport get_dev_data() iommu/vt-d: Fix compile warning iommu/vt-d: Remove real DMA lookup in find_domain iommu/vt-d: Allocate domain info for real DMA sub-devices iommu/vt-d: Only clear real DMA device's context entries iommu: Remove iommu_sva_ops::mm_exit() uacce: Remove mm_exit() op iommu/sun50i: Constify sun50i_iommu_ops iommu/hyper-v: Constify hyperv_ir_domain_ops iommu/vt-d: Use pci_ats_supported() iommu/arm-smmu-v3: Use pci_ats_supported() ...

Merge branches 'arm/msm', 'arm/allwinner', 'arm/smmu', 'x86/vt-d', 'hyper-v', 'core' and 'x86/amd' into next

2020-06-02T08:32:04+00:00

iommu: Remove iommu_sva_ops::mm_exit()

2020-05-29T12:52:53+00:00

After binding a device to an mm, device drivers currently need to register a mm_exit handler. This function is called when the mm exits, to gracefully stop DMA targeting the address space and flush page faults to the IOMMU. This is deemed too complex for the MMU release() notifier, which may be triggered by any mmput() invocation, from about 120 callsites [1]. The upcoming SVA module has an example of such complexity: the I/O Page Fault handler would need to call mmput_async() instead of mmput() after handling an IOPF, to avoid triggering the release() notifier which would in turn drain the IOPF queue and lock up. Another concern is the DMA stop function taking too long, up to several minutes [2]. For some mmput() callers this may disturb other users. For example, if the OOM killer picks the mm bound to a device as the victim and that mm's memory is locked, if the release() takes too long, it might choose additional innocent victims to kill. To simplify the MMU release notifier, don't forward the notification to device drivers. Since they don't stop DMA on mm exit anymore, the PASID lifetime is extended: (1) The device driver calls bind(). A PASID is allocated. Here any DMA fault is handled by mm, and on error we don't print anything to dmesg. Userspace can easily trigger errors by issuing DMA on unmapped buffers. (2) exit_mmap(), for example the process took a SIGKILL. This step doesn't happen during normal operations. Remove the pgd from the PASID table, since the page tables are about to be freed. Invalidate the IOTLBs. Here the device may still perform DMA on the address space. Incoming transactions are aborted but faults aren't printed out. ATS Translation Requests return Successful Translation Completions with R=W=0. PRI Page Requests return with Invalid Request. (3) The device driver stops DMA, possibly following release of a fd, and calls unbind(). PASID table is cleared, IOTLB invalidated if necessary. The page fault queues are drained, and the PASID is freed. If DMA for that PASID is still running here, something went seriously wrong and errors should be reported. For now remove iommu_sva_ops entirely. We might need to re-introduce them at some point, for example to notify device drivers of unhandled IOPF. [1] https://lore.kernel.org/linux-iommu/20200306174239.GM31668@ziepe.ca/ [2] https://lore.kernel.org/linux-iommu/4d68da96-0ad5-b412-5987-2f7a6aa796c3@amd.com/ Signed-off-by: Jean-Philippe Brucker Acked-by: Jacob Pan Acked-by: Lu Baolu Link: https://lore.kernel.org/r/20200423125329.782066-3-jean-philippe@linaro.org Signed-off-by: Joerg Roedel

iommu: Remove functions that support private domain

2020-05-15T10:00:36+00:00

After moving iommu_group setup to iommu core code [1][2] and removing private domain support in vt-d [3], there are no users for functions such as iommu_request_dm_for_dev(), iommu_request_dma_domain_for_dev() and request_default_domain_for_dev(). So, remove these functions. [1] commit dce8d6964ebd ("iommu/amd: Convert to probe/release_device() call-backs") [2] commit e5d1841f18b2 ("iommu/vt-d: Convert to probe/release_device() call-backs") [3] commit 327d5b2fee91 ("iommu/vt-d: Allow 32bit devices to uses DMA domain") Signed-off-by: Sai Praneeth Prakhya Cc: Joerg Roedel Cc: Lu Baolu Link: https://lore.kernel.org/r/20200513224721.20504-1-sai.praneeth.prakhya@intel.com Signed-off-by: Joerg Roedel

iommu: add generic helper for mapping sgtable objects

2020-05-13T13:48:20+00:00

struct sg_table is a common structure used for describing a memory buffer. It consists of a scatterlist with memory pages and DMA addresses (sgl entry), as well as the number of scatterlist entries: CPU pages (orig_nents entry) and DMA mapped pages (nents entry). It turned out that it was a common mistake to misuse nents and orig_nents entries, calling mapping functions with a wrong number of entries. To avoid such issues, lets introduce a common wrapper operating directly on the struct sg_table objects, which take care of the proper use of the nents and orig_nents entries. Signed-off-by: Marek Szyprowski Acked-by: Joerg Roedel Reviewed-by: Robin Murphy Signed-off-by: Christoph Hellwig

iommu: Unexport iommu_group_get_for_dev()

2020-05-05T12:36:14+00:00

The function is now only used in IOMMU core code and shouldn't be used outside of it anyway, so remove the export for it. Signed-off-by: Joerg Roedel Tested-by: Marek Szyprowski Acked-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200429133712.31431-35-joro@8bytes.org Signed-off-by: Joerg Roedel

iommu: Remove add_device()/remove_device() code-paths

2020-05-05T12:36:14+00:00

All drivers are converted to use the probe/release_device() call-backs, so the add_device/remove_device() pointers are unused and the code using them can be removed. Signed-off-by: Joerg Roedel Tested-by: Marek Szyprowski Acked-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200429133712.31431-33-joro@8bytes.org Signed-off-by: Joerg Roedel

iommu: Export bus_iommu_probe() and make is safe for re-probing

2020-05-05T12:36:13+00:00

Add a check to the bus_iommu_probe() call-path to make sure it ignores devices which have already been successfully probed. Then export the bus_iommu_probe() function so it can be used by IOMMU drivers. Signed-off-by: Joerg Roedel Tested-by: Marek Szyprowski Acked-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200429133712.31431-14-joro@8bytes.org Signed-off-by: Joerg Roedel

iommu: Add probe_device() and release_device() call-backs

2020-05-05T12:36:12+00:00

Add call-backs to 'struct iommu_ops' as an alternative to the add_device() and remove_device() call-backs, which will be removed when all drivers are converted. The new call-backs will not setup IOMMU groups and domains anymore, so also add a probe_finalize() call-back where the IOMMU driver can do per-device setup work which require the device to be set up with a group and a domain. Signed-off-by: Joerg Roedel Tested-by: Marek Szyprowski Acked-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200429133712.31431-8-joro@8bytes.org Signed-off-by: Joerg Roedel

iommu: Add def_domain_type() callback in iommu_ops

2020-05-05T12:36:12+00:00

Some devices are reqired to use a specific type (identity or dma) of default domain when they are used with a vendor iommu. When the system level default domain type is different from it, the vendor iommu driver has to request a new default domain with iommu_request_dma_domain_for_dev() and iommu_request_dm_for_dev() in the add_dev() callback. Unfortunately, these two helpers only work when the group hasn't been assigned to any other devices, hence, some vendor iommu driver has to use a private domain if it fails to request a new default one. This adds def_domain_type() callback in the iommu_ops, so that any special requirement of default domain for a device could be aware by the iommu generic layer. Signed-off-by: Sai Praneeth Prakhya Signed-off-by: Lu Baolu [ jroedel@suse.de: Added iommu_get_def_domain_type() function and use it to allocate the default domain ] Co-developed-by: Joerg Roedel Signed-off-by: Joerg Roedel Tested-by: Marek Szyprowski Acked-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200429133712.31431-3-joro@8bytes.org Signed-off-by: Joerg Roedel