0bbc82e4ec
Add support for basic live migration functionality in VFIO over virtio-net devices, aligned with the virtio device specification 1.4. This includes the following VFIO features: VFIO_MIGRATION_STOP_COPY, VFIO_MIGRATION_P2P. The implementation registers with the VFIO subsystem using vfio_pci_core and then incorporates the virtio-specific logic for the migration process. The migration follows the definitions in uapi/vfio.h and leverages the virtio VF-to-PF admin queue command channel for execution device parts related commands. Additional Notes: ----------------- The kernel protocol between the source and target devices contains a header with metadata, including record size, tag, and flags. The record size allows the target to recognize and read a complete image from the source before passing the device part data. This adheres to the virtio device specification, which mandates that partial device parts cannot be supplied. The tag and flags serve as placeholders for future extensions of the kernel protocol between the source and target, ensuring backward and forward compatibility. Both the source and target comply with the virtio device specification by using a device part object with a unique ID as part of the migration process. Since this resource is limited to a maximum of 255, its lifecycle is confined to periods with an active live migration flow. According to the virtio specification, a device has only two modes: RUNNING and STOPPED. As a result, certain VFIO transitions (i.e., RUNNING_P2P->STOP, STOP->RUNNING_P2P) are treated as no-ops. When transitioning to RUNNING_P2P, the device state is set to STOP, and it will remain STOPPED until the transition out of RUNNING_P2P->RUNNING, at which point it returns to RUNNING. During transition to STOP, the virtio device only stops initiating outgoing requests(e.g. DMA, MSIx, etc.) but still must accept incoming operations. Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/20241113115200.209269-6-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.