| Message ID | 20250313124753.185090-1-yi.l.liu@intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | vfio-pci support pasid attach/detach | expand |
On Thu, 13 Mar 2025 05:47:48 -0700 Yi Liu <yi.l.liu@intel.com> wrote: > This series introduces the PASID attach/detach user APIs (uAPIs) that > allow userspace to attach or detach a device's PASID to or from a specified > IOAS/hwpt. Currently, only the vfio-pci driver is enabled in this series. > > Following this update, PASID-capable devices bound to vfio-pci can report > PASID capabilities to userspace and virtual machines (VMs), facilitating > PASID use cases such as Shared Virtual Addressing (SVA). In discussions > about reporting the virtual PASID (vPASID) to VMs [1], it was agreed that > the userspace virtual machine monitor (VMM) will synthesize the vPASID > capability. The VMM must identify a suitable location to insert the vPASID > capability, including handling hidden bits for certain devices. However, > this responsibility lies with userspace and is not the focus of this series. > > This series begins by adding helpers for PASID attachment in the vfio core, > then extends the device character device (cdev) attach/detach ioctls to > support PASID attach/detach operations. At the conclusion of this series, > the IOMMU_GET_HW_INFO ioctl is extended to report PCI PASID capabilities > to userspace. Userspace should verify this capability before utilizing any > PASID-related uAPIs provided by VFIO, as agreed in [2]. This series depends > on the iommufd PASID attach/detach series [3]. > > The complete code is available at [4] and has been tested with a modified > QEMU branch [5]. What's missing for this to go in and which tree will take it? At a glance it seems like 4/ needs a PCI sign-off and 5/ needs an IOMMUFD sign-off. Thanks, Alex
This series introduces the PASID attach/detach user APIs (uAPIs) that allow userspace to attach or detach a device's PASID to or from a specified IOAS/hwpt. Currently, only the vfio-pci driver is enabled in this series. Following this update, PASID-capable devices bound to vfio-pci can report PASID capabilities to userspace and virtual machines (VMs), facilitating PASID use cases such as Shared Virtual Addressing (SVA). In discussions about reporting the virtual PASID (vPASID) to VMs [1], it was agreed that the userspace virtual machine monitor (VMM) will synthesize the vPASID capability. The VMM must identify a suitable location to insert the vPASID capability, including handling hidden bits for certain devices. However, this responsibility lies with userspace and is not the focus of this series. This series begins by adding helpers for PASID attachment in the vfio core, then extends the device character device (cdev) attach/detach ioctls to support PASID attach/detach operations. At the conclusion of this series, the IOMMU_GET_HW_INFO ioctl is extended to report PCI PASID capabilities to userspace. Userspace should verify this capability before utilizing any PASID-related uAPIs provided by VFIO, as agreed in [2]. This series depends on the iommufd PASID attach/detach series [3]. The complete code is available at [4] and has been tested with a modified QEMU branch [5]. [1] https://lore.kernel.org/kvm/BN9PR11MB5276318969A212AD0649C7BE8CBE2@BN9PR11MB5276.namprd11.prod.outlook.com/ [2] https://lore.kernel.org/kvm/4f2daf50-a5ad-4599-ab59-bcfc008688d8@intel.com/ [3] https://lore.kernel.org/linux-iommu/20250313123532.103522-1-yi.l.liu@intel.com/ [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: v8: - Rebased on top of the latest iommufd series, mainly using the latest kAPI for pasid attach v7: https://lore.kernel.org/kvm/20250216054638.24603-1-yi.l.liu@intel.com/#t - Add Alex's and Kevin's r-b on vfio patches - Minor tweaks on patch 04 (Kevin) v6: https://lore.kernel.org/kvm/20241219133534.16422-1-yi.l.liu@intel.com/ - 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@intel.com/ - 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@intel.com/ - 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@intel.com/ - 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@intel.com/ - 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@intel.com/ - Report PASID capability via VFIO_DEVICE_FEATURE (Alex) rfc: https://lore.kernel.org/linux-iommu/20230926093121.18676-1-yi.l.liu@intel.com/ 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 | 35 +++++++++- 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 | 14 ++++ 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, 401 insertions(+), 25 deletions(-)