From: David Matlack <dmatlack@google.com>
To: Alex Williamson <alex@shazbot.org>
Cc: "Adithya Jayachandran" <ajayachandra@nvidia.com>,
"Alexander Graf" <graf@amazon.com>,
"Alex Mastro" <amastro@fb.com>,
"Alistair Popple" <apopple@nvidia.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Ankit Agrawal" <ankita@nvidia.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Chris Li" <chrisl@kernel.org>,
"David Matlack" <dmatlack@google.com>,
"David Rientjes" <rientjes@google.com>,
"Jacob Pan" <jacob.pan@linux.microsoft.com>,
"Jason Gunthorpe" <jgg@nvidia.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Jonathan Corbet" <corbet@lwn.net>,
"Josh Hilke" <jrhilke@google.com>,
"Kevin Tian" <kevin.tian@intel.com>,
kexec@lists.infradead.org, kvm@vger.kernel.org,
"Leon Romanovsky" <leon@kernel.org>,
"Leon Romanovsky" <leonro@nvidia.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
linux-pci@vger.kernel.org, "Lukas Wunner" <lukas@wunner.de>,
"Michał Winiarski" <michal.winiarski@intel.com>,
"Mike Rapoport" <rppt@kernel.org>,
"Parav Pandit" <parav@nvidia.com>,
"Pasha Tatashin" <pasha.tatashin@soleen.com>,
"Pranjal Shrivastava" <praan@google.com>,
"Pratyush Yadav" <pratyush@kernel.org>,
"Raghavendra Rao Ananta" <rananta@google.com>,
"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
"Saeed Mahameed" <saeedm@nvidia.com>,
"Samiullah Khawaja" <skhawaja@google.com>,
"Shuah Khan" <skhan@linuxfoundation.org>,
"Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
"Tomita Moeko" <tomitamoeko@gmail.com>,
"Vipin Sharma" <vipinsh@google.com>,
"Vivek Kasireddy" <vivek.kasireddy@intel.com>,
"William Tu" <witu@nvidia.com>, "Yi Liu" <yi.l.liu@intel.com>,
"Zhu Yanjun" <yanjun.zhu@linux.dev>
Subject: [PATCH v2 00/22] vfio/pci: Base Live Update support for VFIO device files
Date: Thu, 29 Jan 2026 21:24:47 +0000 [thread overview]
Message-ID: <20260129212510.967611-1-dmatlack@google.com> (raw)
This series can be found on GitHub:
https://github.com/dmatlack/linux/tree/liveupdate/vfio/cdev/v2
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:
- Preservation of iommufd files [1]
- Preservation of IOMMU driver state
- Preservation of PCI state (BAR resources, device state, bridge state, ...)
- Preservation of vfio-pci driver state
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.
Changelog
---------
v2:
- Rebase on top of linux-next (tag: next-20260115)
- Add missing EXPORT_SYMBOL_GPLs in LUO (Zhu)
- Add Missing EXPORT_SYMBOL_GPLs for vfio_device_fops (Zhu)
- Fix circular dependency between vfio-pci-core and vfio-pci (Zhu)
- Handle pci=assign-busses (Lukas)
- Drop driver_override patch (Jason)
- Use kho_alloc_preserve(), kho_unpreserve_free(), kho_restore_free() (Pasha)
- Don't access PCI FLB after device initialization (Jason)
- Fix folio leak in vfio_pci_liveupdate_retrieve() (Alex)
- Add Documentation (Pasha)
v1: https://lore.kernel.org/kvm/20251126193608.2678510-1-dmatlack@google.com/
rfc: https://lore.kernel.org/kvm/20251018000713.677779-1-vipinsh@google.com/
Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Adithya Jayachandran <ajayachandra@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Parav Pandit <parav@nvidia.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: William Tu <witu@nvidia.com>
Cc: Jacob Pan <jacob.pan@linux.microsoft.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pratyush Yadav <pratyush@kernel.org>
Cc: Samiullah Khawaja <skhawaja@google.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Josh Hilke <jrhilke@google.com>
Cc: David Rientjes <rientjes@google.com>
[1] https://lore.kernel.org/linux-iommu/20251202230303.1017519-1-skhawaja@google.com/
David Matlack (13):
liveupdate: Export symbols needed by modules
PCI: Add API to track PCI devices preserved across Live Update
PCI: Inherit bus numbers from previous kernel during Live Update
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: Document VFIO device file preservation
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/userspace-api/liveupdate.rst | 144 ++++++++++
MAINTAINERS | 1 +
drivers/pci/Makefile | 1 +
drivers/pci/liveupdate.c | 212 +++++++++++++++
drivers/pci/probe.c | 23 +-
drivers/vfio/device_cdev.c | 25 +-
drivers/vfio/group.c | 9 +
drivers/vfio/pci/Makefile | 1 +
drivers/vfio/pci/vfio_pci.c | 11 +-
drivers/vfio/pci/vfio_pci_core.c | 24 +-
drivers/vfio/pci/vfio_pci_liveupdate.c | 246 +++++++++++++++++
drivers/vfio/pci/vfio_pci_priv.h | 16 ++
drivers/vfio/vfio.h | 13 -
drivers/vfio/vfio_main.c | 23 +-
include/linux/kho/abi/pci.h | 55 ++++
include/linux/kho/abi/vfio_pci.h | 45 +++
include/linux/pci.h | 47 ++++
include/linux/vfio.h | 58 ++++
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 +++++++
35 files changed, 1410 insertions(+), 88 deletions(-)
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: 9b7977f9e39b7768c70c2aa497f04e7569fd3e00
--
2.53.0.rc1.225.gd81095ad13-goog
next reply other threads:[~2026-01-29 21:25 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-29 21:24 David Matlack [this message]
2026-01-29 21:24 ` [PATCH v2 01/22] liveupdate: Export symbols needed by modules David Matlack
2026-01-29 21:24 ` [PATCH v2 02/22] PCI: Add API to track PCI devices preserved across Live Update David Matlack
2026-02-01 6:38 ` Zhu Yanjun
2026-02-02 18:14 ` David Matlack
2026-02-04 0:10 ` Yanjun.Zhu
2026-02-20 19:03 ` David Matlack
2026-01-29 21:24 ` [PATCH v2 03/22] PCI: Inherit bus numbers from previous kernel during " David Matlack
2026-01-29 21:24 ` [PATCH v2 04/22] vfio/pci: Register a file handler with Live Update Orchestrator David Matlack
2026-02-06 22:37 ` Yanjun.Zhu
2026-02-06 23:14 ` David Matlack
2026-01-29 21:24 ` [PATCH v2 05/22] vfio/pci: Preserve vfio-pci device files across Live Update David Matlack
2026-01-29 21:24 ` [PATCH v2 06/22] vfio/pci: Retrieve preserved device files after " David Matlack
2026-01-29 21:24 ` [PATCH v2 07/22] vfio/pci: Notify PCI subsystem about devices preserved across " David Matlack
2026-01-29 21:24 ` [PATCH v2 08/22] vfio: Enforce preserved devices are retrieved via LIVEUPDATE_SESSION_RETRIEVE_FD David Matlack
2026-01-29 21:24 ` [PATCH v2 09/22] vfio/pci: Store incoming Live Update state in struct vfio_pci_core_device David Matlack
2026-01-29 21:24 ` [PATCH v2 10/22] vfio/pci: Skip reset of preserved device after Live Update David Matlack
2026-01-29 22:21 ` Jacob Pan
2026-01-29 22:33 ` David Matlack
2026-01-30 0:31 ` Jacob Pan
2026-01-29 21:24 ` [PATCH v2 11/22] docs: liveupdate: Document VFIO device file preservation David Matlack
2026-01-29 21:24 ` [PATCH v2 12/22] selftests/liveupdate: Move luo_test_utils.* into a reusable library David Matlack
2026-01-29 21:25 ` [PATCH v2 13/22] selftests/liveupdate: Add helpers to preserve/retrieve FDs David Matlack
2026-01-29 21:25 ` [PATCH v2 14/22] vfio: selftests: Build liveupdate library in VFIO selftests David Matlack
2026-01-29 21:25 ` [PATCH v2 15/22] vfio: selftests: Add Makefile support for TEST_GEN_PROGS_EXTENDED David Matlack
2026-01-29 21:25 ` [PATCH v2 16/22] vfio: selftests: Add vfio_pci_liveupdate_uapi_test David Matlack
2026-01-29 21:25 ` [PATCH v2 17/22] vfio: selftests: Initialize vfio_pci_device using a VFIO cdev FD David Matlack
2026-01-29 21:25 ` [PATCH v2 18/22] vfio: selftests: Add vfio_pci_liveupdate_kexec_test David Matlack
2026-01-29 21:25 ` [PATCH v2 19/22] vfio: selftests: Expose iommu_modes to tests David Matlack
2026-01-29 21:25 ` [PATCH v2 20/22] vfio: selftests: Expose low-level helper routines for setting up struct vfio_pci_device David Matlack
2026-01-29 21:25 ` [PATCH v2 21/22] vfio: selftests: Verify that opening VFIO device fails during Live Update David Matlack
2026-01-29 21:25 ` [PATCH v2 22/22] vfio: selftests: Add continuous DMA to vfio_pci_liveupdate_kexec_test David Matlack
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