v6 is a replacement of what's in iommufd next: https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git/log/?h=for-next base-commit: b5f9e63278d6f32789478acf1ed41d21d92b36cf (from the iommufd tree) =========>8========= Presented herewith is a series that extends IOMMUFD to have IOMMU hardware support for dirty bit in the IOPTEs. Today, AMD Milan (or more recent) supports it while ARM SMMUv3.2 alongside VT-D rev3.x also do support. One intended use-case (but not restricted!) is to support Live Migration with SR-IOV, specially useful for live migrateable PCI devices that can't supply its own dirty tracking hardware blocks amongst others. At a quick glance, IOMMUFD lets the userspace create the IOAS with a set of a IOVA ranges mapped to some physical memory composing an IO pagetable. This is then created via HWPT_ALLOC or attached to a particular device/hwpt, consequently creating the IOMMU domain and share a common IO page table representing the endporint DMA-addressable guest address space. In IOMMUFD Dirty tracking (since v2 of the series) it will require via the HWPT_ALLOC model only, as opposed to simpler autodomains model. The result is an hw_pagetable which represents the iommu_domain which will be directly manipulated. The IOMMUFD UAPI, and the iommu/iommufd kAPI are then extended to provide: 1) Enforcement that only devices with dirty tracking support are attached to an IOMMU domain, to cover the case where this isn't all homogenous in the platform. While initially this is more aimed at possible heterogenous nature of ARM while x86 gets future proofed, should any such ocasion occur. The device dirty tracking enforcement on attach_dev is made whether the dirty_ops are set or not. Given that attach always checks for dirty ops and IOMMU_CAP_DIRTY, while writing this it almost wanted this to move to upper layer but semantically iommu driver should do the checking. 2) Toggling of Dirty Tracking on the iommu_domain. We model as the most common case of changing hardware translation control structures dynamically (x86) while making it easier to have an always-enabled mode. In the RFCv1, the ARM specific case is suggested to be always enabled instead of having to enable the per-PTE DBM control bit (what I previously called "range tracking"). Here, setting/clearing tracking means just clearing the dirty bits at start. The 'real' tracking of whether dirty tracking is enabled is stored in the IOMMU driver, hence no new fields are added to iommufd pagetable structures, except for the iommu_domain dirty ops part via adding a dirty_ops field to iommu_domain. We use that too for IOMMUFD to know if dirty tracking is supported and toggleable without having iommu drivers replicate said checks. 3) Add a capability probing for dirty tracking, leveraging the per-device iommu_capable() and adding a IOMMU_CAP_DIRTY. It extends the GET_HW_INFO ioctl which takes a device ID to return some generic capabilities *in addition*. Possible values enumarated by `enum iommufd_hw_capabilities`. 4) Read the I/O PTEs and marshal its dirtyiness into a bitmap. The bitmap indexes on a page_size basis the IOVAs that got written by the device. While performing the marshalling also drivers need to clear the dirty bits from IOPTE and allow the kAPI caller to batch the much needed IOTLB flush. There's no copy of bitmaps to userspace backed memory, all is zerocopy based to not add more cost to the iommu driver IOPT walker. This shares functionality with VFIO device dirty tracking via the IOVA bitmap APIs. So far this is a test-and-clear kind of interface given that the IOPT walk is going to be expensive. In addition this also adds the ability to read dirty bit info without clearing the PTE info. This is meant to cover the unmap-and-read-dirty use-case, and avoid the second IOTLB flush. The only dependency is: * Have domain_alloc_user() API with flags [2] already queued (iommufd/for-next). The series is organized as follows: * Patches 1-4: Takes care of the iommu domain operations to be added. The idea is to abstract iommu drivers from any idea of how bitmaps are stored or propagated back to the caller, as well as allowing control/batching over IOTLB flush. So there's a data structure and an helper that only tells the upper layer that an IOVA range got dirty. This logic is shared with VFIO and it's meant to walking the bitmap user memory, and kmap-ing plus setting bits as needed. IOMMU driver just has an idea of a 'dirty bitmap state' and recording an IOVA as dirty. * Patches 5-9, 13-18: Adds the UAPIs for IOMMUFD, and selftests. The selftests cover some corner cases on boundaries handling of the bitmap and various bitmap sizes that exercise. I haven't included huge IOVA ranges to avoid risking the selftests failing to execute due to OOM issues of mmaping big buffers. * Patches 10-11: AMD IOMMU implementation, particularly on those having HDSup support. Tested with a Qemu amd-iommu with HDSUp emulated[0]. And tested with live migration with VFs (but with IOMMU dirty tracking). * Patches 12: Intel IOMMU rev3.x+ implementation. Tested with a Qemu based intel-iommu vIOMMU with SSADS emulation support[0]. On AMD/Intel I have tested this with emulation and then live migration in AMD hardware; The qemu iommu emulation bits are to increase coverage of this code and hopefully make this more broadly available for fellow contributors/devs, old version[1]; it uses Yi's 2 commits to have hw_info() supported (still needs a bit of cleanup) on top of a recent Zhenzhong series of IOMMUFD QEMU bringup work: see here[0]. It includes IOMMUFD dirty tracking for Live migration and with live migration tested. I won't be exactly following up a v2 of QEMU patches until IOMMUFD tracking lands. Feedback or any comments are very much appreciated. Thanks! Joao [0] https://github.com/jpemartins/qemu/commits/iommufd-v3 [1] https://lore.kernel.org/qemu-devel/20220428211351.3897-1-joao.m.martins@xxxxxxxxxx/ [2] https://lore.kernel.org/linux-iommu/20230919092523.39286-1-yi.l.liu@xxxxxxxxx/ [3] https://github.com/jpemartins/linux/commits/iommufd-v3 [4] https://lore.kernel.org/linux-iommu/20230518204650.14541-1-joao.m.martins@xxxxxxxxxx/ [5] https://lore.kernel.org/kvm/20220428210933.3583-1-joao.m.martins@xxxxxxxxxx/ [6] https://github.com/jpemartins/linux/commits/smmu-iommufd-v3 [7] https://lore.kernel.org/linux-iommu/20230923012511.10379-1-joao.m.martins@xxxxxxxxxx/ [8] https://lore.kernel.org/linux-iommu/20231018202715.69734-1-joao.m.martins@xxxxxxxxxx/ [9] https://lore.kernel.org/linux-iommu/20231020222804.21850-1-joao.m.martins@xxxxxxxxxx/ Changes since v5[9]: * Fixes various linux-next/krobot build warnings and failures namely: - Move IOMMUFD_DRIVER kconfig definition changes into drivers/iommu/Kconfig to address a arm32 issue (with !IOMMU_SUPPORT) module dependency warning https://lore.kernel.org/kvm/20231023115520.3530120-1-arnd@xxxxxxxxxx/ - Implement the !IOMMU_API prototypes for patch 4, fixing a sparc64 randconfig build warning when !IOMMU_API is done while having ARM32 IO_PGTABLE builtin https://lore.kernel.org/linux-mm/202310232131.TOhkKzZa-lkp@xxxxxxxxx/ - Fix htmldocs warnings in the individual patches: https://lore.kernel.org/linux-next/20231023164721.1cb43dd6@xxxxxxxxxxxxxxxx/ - Fix lack of div_u64 build error in 32-bit builds (i386, arm32, xtensa, microblaze) by reworking all checks in iommufd_check_iova_ranges() and moving it into iopt_read_and_clear_data(). The checks being redone no longer implement a u64 division, while improving the range checks all together. My 32-bit kernel compilation failures are at least fixed after this and I haven't spotted any warnings from this series. https://lore.kernel.org/linux-iommu/b7834d1e-d198-45ee-b15d-12bd235bc57f@xxxxxxxxxxxxxxxx/ https://lore.kernel.org/oe-kbuild-all/202310231933.c8k54ybn-lkp@xxxxxxxxx/ https://lore.kernel.org/oe-kbuild-all/202310240246.FyXNZrbZ-lkp@xxxxxxxxx/ https://lore.kernel.org/lkml/9e56e94d-536e-435a-afb0-4738e6eddedc@xxxxxxxxxxxxx/ * Comments in v5 not triggered by krobot (yet): - Fix GET_DIRTY_BITMAP selftest to copy bitmap data (when we set in the mock-domain pagetables) instead of directly changing user memory. This was leading to selftests run failures as reported by Nicolin Chen - Fix a build issue of selftests which included bitmap.h header headers, by importing the implementation from include/asm-generic/bitops/generic-non-atomic.h and avoid the non-UAPI headers all together. While doing so use set_bit() instead of __set_bit(). Also reported by Nicolin Chen - Fix GET_DIRTY_BITMAP struct declaration to have a u64 data instead of a pointer. Change the io_pagetable reflecting bitmap::data type change to have u64_to_user_ptr() as it should be done. (Arnd Bergmann) - Run through clang-format and fix any issues where applicable (3 small formatting things only, but left others that were seemingly according to the style of the file). - Rename intel iommu patch subject to have SS instead of SL as the latter is old VTd spec naming. And use 'iommu/vt-d' for component name instead of 'iommu/intel'. Rename slads_supported() into ssads_supported() to adhere to the new naming. (Yi Liu) Changes since v4[8]: * Rename HWPT_SET_DIRTY to HWPT_SET_DIRTY_TRACKING * Rename IOMMU_CAP_DIRTY to IOMMU_CAP_DIRTY_TRACKING * Rename HWPT_GET_DIRTY_IOVA to HWPT_GET_DIRTY_BITMAP * Rename IOMMU_HWPT_ALLOC_ENFORCE_DIRTY to IOMMU_HWPT_ALLOC_DIRTY_TRACKING including commit messages, code comments. Additionally change the variable in drivers from enforce_dirty to dirty_tracking. * Reflect all the mass renaming in commit messages/structs/docs. * Fix the enums prefix to be IOMMU_HWPT like everyone else * UAPI docs fixes/spelling and minor consistency issues/adjustments * Change function exit style in __iommu_read_and_clear_dirty to return right away instead of storing ret and returning at the end. * Check 0 page_size and replace find-first-bit + left-shift with a simple divide in iommufd_check_iova_range() * Handle empty iommu domains when setting dirty tracking in intel-iommu; Verified and amd-iommu was already the case. * Remove unnecessary extra check for PGTT type * Fix comment on function clearing the SLADE bit * Fix wrong check that validates domain_alloc_user() accepted flags in amd-iommu driver * Skip IOTLB domain flush if no devices exist on the iommu domain, while setting dirty tracking in amd-iommu driver. * Collect Reviewed-by tags by Jason, Lu Baolu, Brett, Kevin, Alex Changes since v3[7]: * Consolidate previous patch 9 and 10 into a single patch, while removing iommufd_dirty_bitmap structure to instead use the UAPI defined structure iommu_hwpt_get_dirty_iova and pass around internally in iommufd. * Iterate over areas from within the IOVA bitmap iterator * Drop check for specific flags in hw_pagetable * Drop assignment that calculates iopt_alignment, to instead use iopt_alignment directly * Move IOVA bitmap into iommufd and introduce IOMMUFD_DRIVER bool kconfig which designates the usage of dirty tracking related bitmaps (i.e. VFIO and IOMMU drivers right now). * Update IOVA bitmap header files to account for IOMMUFD_DRIVER being disabled * Sort new IOMMUFD ioctls accordingly * Move IOVA bitmap symbols to IOMMUFD namespace and update its users by importing new namespace (new patch 3) * Remove AMD IOMMU kernel log feature printing from series * Remove struct amd_iommu from do_iommu_domain_alloc() function and derive it from within do_iommu_domain_alloc(). * Consolidate pte_test_dirty() and pte_test_and_clear_dirty() by passing flags and deciding whether to test or test_and_clear. * Add a comment on top of the -EINVAL attach_device() failure when dirty tracking is enforcement but IOMMU does not support dirty tracking * Add Reviewed-by given by Suravee * Select IOMMUFD_DRIVER if IOMMUFD is enabled on supported IOMMU drivers * Remove spurious rcu_read_{,un}lock() from Intel/AMD iommus * Fix unwinding in dirty tracking set failure case in intel-iommu * Avoid unnecesary locking when checking dmar_domain::dirty_tracking * Rename intel_iommu_slads_supported() to a slads_supported() macro following intel-iommu style * Change the XOR check into a == in set_dirty_tracking iommu op * Consolidate PTE test or test-and-clear into single helper * Improve intel_pasid_setup_dirty_tracking() to: use rate limited printk; avoid unnecessary update if state is already the desired one; do a clflush on non-coherent devices; remove the qi_flush_piotlb(); and fail on unsupported pgtts. * Remove the first_level support and always fail domain_alloc_user on those cases with it being no use case ATM. Doing so lets us remove some code for such handling in set_dirty_tracking * Error out the pasid device attach when dirty tracking is enforced as we don't support that either. * Reorganize the series to have selftests at the end, and core/driver enablement first. Changes since RFCv2[4]: * Testing has always occured on the new code, but now it has seen Live Migration coverage with extra QEMU work on AMD hardware. * General commit message improvements * Remove spurious headers in selftests * Exported some symbols to actually allow things to build when IOMMUFD is built as a module. (Alex Williamson) * Switch the enforcing to be done on IOMMU domain allocation via domain_alloc_user (Jason, Robin, Lu Baolu) * Removed RCU series from Lu Baolu (Jason) * Switch set_dirty/read_dirty/clear_dirty to down_read() (Jason) * Make sure it check for area::pages (Jason) * Move clearing dirties before set dirty a helper (Jason) * Avoid breaking IOMMUFD selftests UAPI (Jason) * General improvements to testing * Add coverage to new out_capabilities support in HW_INFO. * Address Shameer/Robin comments in smmu-v3 (code is on a branch[6]) - Properly check for FEAT_HD together with COHERENCY - Remove the pgsize_bitmap check - Limit the quirk set to s1 pgtbl_cfg. - Fix commit message on dubious sentence on DBM usecase Changes since RFCv1[5]: Too many changes but the major items were: * Majorirty of the changes from Jason/Kevin/Baolu/Suravee: - Improve structure and rework most commit messages - Drop all of the VFIO-compat series - Drop the unmap-get-dirty API - Tie this to HWPT only, no more autodomains handling; - Rework the UAPI widely by: - Having a IOMMU_DEVICE_GET_CAPS which allows to fetching capabilities of devices, specifically test dirty tracking support for an individual device - Add a enforce-dirty flag to the IOMMU domain via HWPT_ALLOC - SET_DIRTY now clears dirty tracking before asking iommu driver to do so; - New GET_DIRTY_IOVA flag that does not clear dirty bits - Add coverage for all added APIs - Expand GET_DIRTY_IOVA tests to cover IOVA bitmap corner cases tests that I had in separate; I only excluded the Terabyte IOVA range usecases (which test bitmaps 2M+) because those will most likely fail to be run as selftests (not sure yet how I can include those). I am not exactly sure how I can cover those, unless I do 'fake IOVA maps' *somehow* which do not necessarily require real buffers. - Handle most comments in intel-iommu. Only remaining one for v3 is the PTE walker which will be done better. - Handle all comments in amd-iommu, most of which regarding locking. Only one remaining is v3 same as Intel; - Reflect the UAPI changes into iommu driver implementations, including persisting dirty tracking enabling in new attach_dev calls, as well as enforcing attach_dev enforces the requested domain flags; * Comments from Yi Sun in making sure that dirty tracking isn't restricted into SS only, so relax the check for FL support because it's always enabled. (Yi Sun) * Most of code that was in v1 for dirty bitmaps got rewritten and repurpose to also cover VFIO case; so reuse this infra here too for both. (Jason) * Take Robin's suggestion of always enabling dirty tracking and set_dirty just clearing bits on 'activation', and make that a generic property to ensure we always get accurate results between starting and stopping tracking. (Robin Murphy) * Address all comments from SMMUv3 into how we enable/test the DBM, or the bits in the context descriptor with io-pgtable::quirks, etc (Robin, Shameerali) Joao Martins (18): vfio/iova_bitmap: Export more API symbols vfio: Move iova_bitmap into iommufd iommufd/iova_bitmap: Move symbols to IOMMUFD namespace iommu: Add iommu_domain ops for dirty tracking iommufd: Add a flag to enforce dirty tracking on attach iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAP iommufd: Add capabilities to IOMMU_GET_HW_INFO iommufd: Add a flag to skip clearing of IOPTE dirty iommu/amd: Add domain_alloc_user based domain allocation iommu/amd: Access/Dirty bit support in IOPTEs iommu/vt-d: Access/Dirty bit support for SS domains iommufd/selftest: Expand mock_domain with dev_flags iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING iommufd/selftest: Test IOMMU_HWPT_SET_DIRTY_TRACKING iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag drivers/iommu/Kconfig | 4 + drivers/iommu/amd/Kconfig | 1 + drivers/iommu/amd/amd_iommu_types.h | 12 + drivers/iommu/amd/io_pgtable.c | 68 ++++++ drivers/iommu/amd/iommu.c | 144 +++++++++++- drivers/iommu/intel/Kconfig | 1 + drivers/iommu/intel/iommu.c | 103 ++++++++- drivers/iommu/intel/iommu.h | 16 ++ drivers/iommu/intel/pasid.c | 109 +++++++++ drivers/iommu/intel/pasid.h | 4 + drivers/iommu/iommufd/Makefile | 1 + drivers/iommu/iommufd/device.c | 4 + drivers/iommu/iommufd/hw_pagetable.c | 51 ++++- drivers/iommu/iommufd/io_pagetable.c | 172 ++++++++++++++ drivers/iommu/iommufd/iommufd_private.h | 22 ++ drivers/iommu/iommufd/iommufd_test.h | 21 ++ drivers/{vfio => iommu/iommufd}/iova_bitmap.c | 5 +- drivers/iommu/iommufd/main.c | 7 + drivers/iommu/iommufd/selftest.c | 187 +++++++++++++++- drivers/vfio/Makefile | 3 +- drivers/vfio/pci/mlx5/Kconfig | 1 + drivers/vfio/pci/mlx5/main.c | 1 + drivers/vfio/pci/pds/Kconfig | 1 + drivers/vfio/pci/pds/pci_drv.c | 1 + drivers/vfio/vfio_main.c | 1 + include/linux/io-pgtable.h | 4 + include/linux/iommu.h | 70 ++++++ include/linux/iova_bitmap.h | 26 +++ include/uapi/linux/iommufd.h | 96 ++++++++ tools/testing/selftests/iommu/iommufd.c | 211 ++++++++++++++++++ .../selftests/iommu/iommufd_fail_nth.c | 2 +- tools/testing/selftests/iommu/iommufd_utils.h | 206 ++++++++++++++++- 32 files changed, 1528 insertions(+), 27 deletions(-) rename drivers/{vfio => iommu/iommufd}/iova_bitmap.c (98%) -- 2.17.2
