This series can be found on GitHub: https://github.com/dmatlack/linux/tree/liveupdate/vfio/cdev/v3
This series adds the base support to preserve a VFIO device file across a Live Update. "Base support" means that this allows userspace to safely preserve a VFIO device file with LIVEUPDATE_SESSION_PRESERVE_FD and retrieve it with LIVEUPDATE_SESSION_RETRIEVE_FD, but the device itself is not preserved in a fully running state across Live Update. This series aims to provide a foundation on which to build the rest of the device preservation infrastructure, including: 1. Preservation of iommufd files [1] 2. Preservation of IOMMU driver state 3. Preservation of PCI state (BAR resources, device state, bridge state, ...) 4. Preservation of vfio-pci driver state Steps 1 and 2 are already in-progress on the mailing list. We are working on a detailed roadmap for steps 3 and 4. Testing ------- The patches at the end of this series provide comprehensive selftests for the new code added by this series. The selftests have been validated in both a VM environment using a virtio-net PCIe device, and in a baremetal environment on an Intel EMR server with an Intel DSA PCIe device. Here is an example of how to run the new selftests: vfio_pci_liveupdate_uapi_test: $ tools/testing/selftests/vfio/scripts/setup.sh 0000:00:04.0 $ tools/testing/selftests/vfio/vfio_pci_liveupdate_uapi_test 0000:00:04.0 $ tools/testing/selftests/vfio/scripts/cleanup.sh vfio_pci_liveupdate_kexec_test: $ tools/testing/selftests/vfio/scripts/setup.sh 0000:00:04.0 $ tools/testing/selftests/vfio/vfio_pci_liveupdate_kexec_test --stage 1 0000:00:04.0 $ kexec ... $ tools/testing/selftests/vfio/scripts/setup.sh 0000:00:04.0 $ tools/testing/selftests/vfio/vfio_pci_liveupdate_kexec_test --stage 2 0000:00:04.0 $ tools/testing/selftests/vfio/scripts/cleanup.sh It is also possible to run vfio_pci_liveupdate_kexec_test multiple times to preserve multiple devices simultaneously across a Live Update. This series has been tested with up to 8 devices concurrently preserved. Dependencies ------------ This series is built on top of v7.0-rc4 plus a series from Pasha Tatashin to fix the module refcounting in FLB: https://lore.kernel.org/lkml/[email protected]/ Changelog --------- v3: - Add logging & documentation for pci=assign-busses overrides (Pranjal) - Use 2026 in drivers/pci/liveupdate.c (Pranjal) - Use 2026 in drivers/vfio/pci/vfio_pci_liveupdate.c (Pranjal) - Drop incoming/outgoing from PCI APIs (Sami) - Eliminate duplicate extern declarations for vfio_device_fops (Pranjal) - Keep struct vfio_device_file private (Pranjal) - Add comment about not supporting hot-plug (Pranjal) - Add comment about not supporting VFs (Sami) - Better error handling for liveupdate_flb_get_incoming() (Pranjal) - Remove liveupdate_enabled() checks (Zhu) - Remove liveupdate_enabled() checks in vfio_pci_liveupdate_init() (Pranjal) - Drop IOMMU reference from bus number commit message (Bjorn) - Add fabric rationale to commit message (Jason) - Swap incoming ... outgoing ordering in commit message (Bjorn) - Use vfio_device_cdev_opened() instead of df->group (Alex) - Add comments for CONFIG_VFIO_PCI_ZDEV_KVM (Alex) - Add comments for vfio_pci_is_intel_display() (Alex) - Use pci_dev_try_lock() in freeze (Alex) - Fix device reset locking in freeze() (me) - Use u32 for domain in PCI (Bjorn) - Use u32 for domain in VFIO (Bjorn) - Make pci_liveupdate_incoming_nr_devices() private to drivers/pci/ (Bjorn) - Fix dev->liveupdate_incoming readability (Bjorn) - Take pci_ser_delete() out of WARN_ON_ONCE() (Bjorn) - Drop reference to userspace & files from PCI commit message (Bjorn) - Rename __vfio_device_fops_cdev_open() to vfio_device_cdev_open_file() (Alex) - Fix NULL pointer dereference in release() (Alex) - Handle return value of pci_liveupdate_outgoing_preserve() (Alex) - Make pci_liveupdate_unregister_fh() unabe to fail. (Alex) - Move vfio_liveupdate_incoming_is_preserved() to drivers/vfio/vfio.h (Alex) - Add vfio_pci_core_probe_reset() (Alex) - Forward declare ser struct in include/linux/vfio_pci_core.h (Alex) - Bump compatibility string when adding reset_works (Alex) - How will userspace detect partial preservation? (Alex) - Require single device per iommu_group (Jason) - Rename pci_liveupdate_register_fh() to pci_liveupdate_register_flb() (Vipin) - Use ksft_exit_skip() and SKIP() (Vipin) - Move documentation to code (Vipin) - Use __u64 instead of int for token in Live Update selftest helpers (Gemini) - Add documentation for drivers/pci/liveupdate.c (me) v2: https://lore.kernel.org/kvm/[email protected]/ v1: https://lore.kernel.org/kvm/[email protected]/ rfc: https://lore.kernel.org/kvm/[email protected]/ Cc: Pranjal Shrivastava <[email protected]> Cc: Saeed Mahameed <[email protected]> Cc: Adithya Jayachandran <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Parav Pandit <[email protected]> Cc: Leon Romanovsky <[email protected]> Cc: William Tu <[email protected]> Cc: Jacob Pan <[email protected]> Cc: Lukas Wunner <[email protected]> Cc: Pasha Tatashin <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Pratyush Yadav <[email protected]> Cc: Samiullah Khawaja <[email protected]> Cc: Chris Li <[email protected]> Cc: Josh Hilke <[email protected]> Cc: David Rientjes <[email protected]> [1] https://lore.kernel.org/linux-iommu/[email protected]/ David Matlack (15): liveupdate: Export symbols needed by modules PCI: Add API to track PCI devices preserved across Live Update PCI: Require Live Update preserved devices are in singleton iommu_groups PCI: Inherit bus numbers from previous kernel during Live Update docs: liveupdate: Add documentation for PCI vfio/pci: Notify PCI subsystem about devices preserved across Live Update vfio: Enforce preserved devices are retrieved via LIVEUPDATE_SESSION_RETRIEVE_FD vfio/pci: Store incoming Live Update state in struct vfio_pci_core_device docs: liveupdate: Add documentation for VFIO PCI vfio: selftests: Add Makefile support for TEST_GEN_PROGS_EXTENDED vfio: selftests: Add vfio_pci_liveupdate_uapi_test vfio: selftests: Expose iommu_modes to tests vfio: selftests: Expose low-level helper routines for setting up struct vfio_pci_device vfio: selftests: Verify that opening VFIO device fails during Live Update vfio: selftests: Add continuous DMA to vfio_pci_liveupdate_kexec_test Vipin Sharma (9): vfio/pci: Register a file handler with Live Update Orchestrator vfio/pci: Preserve vfio-pci device files across Live Update vfio/pci: Retrieve preserved device files after Live Update vfio/pci: Skip reset of preserved device after Live Update selftests/liveupdate: Move luo_test_utils.* into a reusable library selftests/liveupdate: Add helpers to preserve/retrieve FDs vfio: selftests: Build liveupdate library in VFIO selftests vfio: selftests: Initialize vfio_pci_device using a VFIO cdev FD vfio: selftests: Add vfio_pci_liveupdate_kexec_test Documentation/PCI/liveupdate.rst | 23 + .../admin-guide/kernel-parameters.txt | 6 +- Documentation/core-api/liveupdate.rst | 2 + .../driver-api/vfio_pci_liveupdate.rst | 23 + MAINTAINERS | 2 + drivers/pci/Kconfig | 11 + drivers/pci/Makefile | 1 + drivers/pci/liveupdate.c | 415 ++++++++++++++++++ drivers/pci/pci.h | 14 + drivers/pci/probe.c | 37 +- drivers/vfio/device_cdev.c | 63 ++- drivers/vfio/group.c | 9 + drivers/vfio/pci/Kconfig | 11 + drivers/vfio/pci/Makefile | 1 + drivers/vfio/pci/vfio_pci.c | 14 +- drivers/vfio/pci/vfio_pci_core.c | 90 ++-- drivers/vfio/pci/vfio_pci_liveupdate.c | 328 ++++++++++++++ drivers/vfio/pci/vfio_pci_priv.h | 18 + drivers/vfio/vfio.h | 18 + drivers/vfio/vfio_main.c | 16 +- include/linux/kho/abi/pci.h | 62 +++ include/linux/kho/abi/vfio_pci.h | 45 ++ include/linux/pci.h | 41 ++ include/linux/vfio.h | 13 + include/linux/vfio_pci_core.h | 2 + kernel/liveupdate/luo_core.c | 1 + kernel/liveupdate/luo_file.c | 2 + tools/testing/selftests/liveupdate/.gitignore | 1 + tools/testing/selftests/liveupdate/Makefile | 14 +- .../include/libliveupdate.h} | 11 +- .../selftests/liveupdate/lib/libliveupdate.mk | 20 + .../{luo_test_utils.c => lib/liveupdate.c} | 43 +- .../selftests/liveupdate/luo_kexec_simple.c | 2 +- .../selftests/liveupdate/luo_multi_session.c | 2 +- tools/testing/selftests/vfio/Makefile | 23 +- .../vfio/lib/include/libvfio/iommu.h | 2 + .../lib/include/libvfio/vfio_pci_device.h | 8 + tools/testing/selftests/vfio/lib/iommu.c | 4 +- .../selftests/vfio/lib/vfio_pci_device.c | 60 ++- .../vfio/vfio_pci_liveupdate_kexec_test.c | 256 +++++++++++ .../vfio/vfio_pci_liveupdate_uapi_test.c | 93 ++++ 41 files changed, 1715 insertions(+), 92 deletions(-) create mode 100644 Documentation/PCI/liveupdate.rst create mode 100644 Documentation/driver-api/vfio_pci_liveupdate.rst create mode 100644 drivers/pci/liveupdate.c create mode 100644 drivers/vfio/pci/vfio_pci_liveupdate.c create mode 100644 include/linux/kho/abi/pci.h create mode 100644 include/linux/kho/abi/vfio_pci.h rename tools/testing/selftests/liveupdate/{luo_test_utils.h => lib/include/libliveupdate.h} (80%) create mode 100644 tools/testing/selftests/liveupdate/lib/libliveupdate.mk rename tools/testing/selftests/liveupdate/{luo_test_utils.c => lib/liveupdate.c} (89%) create mode 100644 tools/testing/selftests/vfio/vfio_pci_liveupdate_kexec_test.c create mode 100644 tools/testing/selftests/vfio/vfio_pci_liveupdate_uapi_test.c base-commit: 3251ac3df4374e4e94e4fbecf49ad1573933018a prerequisite-patch-id: 37ebd38e2247ccb02e6a6c7543a378534d69a038 prerequisite-patch-id: 19c8469a9ae5cd13618481dd75012444330f80f9 prerequisite-patch-id: 2ba04f598993e2c2d941c4cd3f2dc1e98905d68b prerequisite-patch-id: fcab928f6ee32a145667822ceca5e4f1f567d530 prerequisite-patch-id: 6d11347278609426baa9eacc1726b32b48d09a25 prerequisite-patch-id: 94a9e8a8cb6004e12de90fcc0068e8a8b12652de prerequisite-patch-id: d658019a7ac7c82ebe4a6c6086457e27460174d3 prerequisite-patch-id: 41e68c9fc8e8c5e493497e87ca13577b3167cf80 -- 2.53.0.983.g0bb29b3bc5-goog
