This adds the pasid attach/detach uAPIs for userspace to attach/detach a PASID of a device to/from a given ioas/hwpt. Only vfio-pci driver is enabled in this series. After this series, PASID-capable devices bound with vfio-pci can report PASID capability to userspace and VM to enable PASID usages like Shared Virtual Addressing (SVA). Based on the discussion about reporting the vPASID to VM [1], it's agreed that we will let the userspace VMM to synthesize the vPASID capability. The VMM needs to figure out a hole to put the vPASID cap. This includes the hidden bits handling for some devices. While, it's up to the userspace, it's not the focus of this series. This series first adds the helpers for pasid attach in vfio core and then extends the device cdev attach/detach ioctls for pasid attach/detach. In the end of this series, the IOMMU_GET_HW_INFO ioctl is extended to report the PCI PASID capability to the userspace. Userspace should check this before using any PASID related uAPIs provided by VFIO, which is the agreement in [2]. This series depends on the iommufd pasid attach/detach series [3]. The completed code can be found at [4], tested with a hacky Qemu branch [5]. [1] https://lore.kernel.org/kvm/BN9PR11MB5276318969A212AD0649C7BE8CBE2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ [2] https://lore.kernel.org/kvm/4f2daf50-a5ad-4599-ab59-bcfc008688d8@xxxxxxxxx/ [3] https://lore.kernel.org/linux-iommu/20241219132746.16193-1-yi.l.liu@xxxxxxxxx/ [4] https://github.com/yiliu1765/iommufd/tree/iommufd_pasid [5] https://github.com/yiliu1765/qemu/tree/wip/zhenzhong/iommufd_nesting_rfcv2-test-pasid Change log: v6: - Drop the vfio_copy_user_data() generalization as it is not totally clear what it would cover. (Alex) - Reworked the patch 03 of v5 a bit. e.g. lift the pasid_{at|de}tach_ioas op test before the second user data copy; make 'if (xend > minsz)' to be 'if (xend)' and remove the comment accordingly. This is because we don't generalize the user data copy now, so xend is either 0 or non-zero, no need to check against minsz. - Make the IOMMU_GET_HW_INFO report out_max_pasid_log2 by checking the dev->iommu->max_pasids. This is because iommu drivers enables PASID as long as it supports. So checking it is enough. Also, it is more friendly to non-PCI PASID supports compared with reading the PCI config space to check if PASID is enabled. - Add selftest coverage for reporting max_pasid_log2 in IOMMU_HW_INFO ioctl. v5: https://lore.kernel.org/kvm/20241108121742.18889-1-yi.l.liu@xxxxxxxxx/ - Fix a wrong return value (Alex) - Fix the policy of setting the xend array per flag extension (Alex) - A separate patch to generalize the code of copy user data (Alex) v4: https://lore.kernel.org/kvm/20241104132732.16759-1-yi.l.liu@xxxxxxxxx/ - Add acked-by for the ida patch from Matthew - Add r-b from Kevin and Jason on patch 01, 02 and 04 of v3 - Add common code to copy user data for the user struct with new fields - Extend the VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT to support pasid, patch 03 is updated per this change. Hence drop r-b of it. (Kevin, Alex) - Add t-b from Zhangfei for patch 4 of v3 - Nits from Vasant v3: https://lore.kernel.org/linux-iommu/20240912131729.14951-1-yi.l.liu@xxxxxxxxx/ - Misc enhancement on patch 01 of v2 (Alex, Jason) - Add Jason's r-b to patch 03 of v2 - Drop the logic that report PASID via VFIO_DEVICE_FEATURE ioctl - Extend IOMMU_GET_HW_INFO to report PASID support (Kevin, Jason, Alex) v2: https://lore.kernel.org/kvm/20240412082121.33382-1-yi.l.liu@xxxxxxxxx/ - Use IDA to track if PASID is attached or not in VFIO. (Jason) - Fix the issue of calling pasid_at[de]tach_ioas callback unconditionally (Alex) - Fix the wrong data copy in vfio_df_ioctl_pasid_detach_pt() (Zhenzhong) - Minor tweaks in comments (Kevin) v1: https://lore.kernel.org/kvm/20231127063909.129153-1-yi.l.liu@xxxxxxxxx/ - Report PASID capability via VFIO_DEVICE_FEATURE (Alex) rfc: https://lore.kernel.org/linux-iommu/20230926093121.18676-1-yi.l.liu@xxxxxxxxx/ Regards, Yi Liu Yi Liu (5): ida: Add ida_find_first_range() vfio-iommufd: Support pasid [at|de]tach for physical VFIO devices vfio: VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT support pasid iommufd: Extend IOMMU_GET_HW_INFO to report PASID capability iommufd/selftest: Add coverage for reporting max_pasid_log2 via IOMMU_HW_INFO drivers/iommu/iommufd/device.c | 33 ++++++++- drivers/pci/ats.c | 33 +++++++++ drivers/vfio/device_cdev.c | 60 +++++++++++++--- drivers/vfio/iommufd.c | 50 +++++++++++++ drivers/vfio/pci/vfio_pci.c | 2 + include/linux/idr.h | 11 +++ include/linux/pci-ats.h | 3 + include/linux/vfio.h | 11 +++ include/uapi/linux/iommufd.h | 14 +++- include/uapi/linux/vfio.h | 29 +++++--- lib/idr.c | 67 ++++++++++++++++++ lib/test_ida.c | 70 +++++++++++++++++++ tools/testing/selftests/iommu/iommufd.c | 18 +++++ .../selftests/iommu/iommufd_fail_nth.c | 3 +- tools/testing/selftests/iommu/iommufd_utils.h | 17 +++-- 15 files changed, 396 insertions(+), 25 deletions(-) -- 2.34.1
