John, Thanos,
On 9/11/26 16:19, Hugo Komatsu wrote:
> This patch series introduces live migration support for vfio-user PCI
> devices, built on top of the VFIO v2 migration interface.
>
> To avoid duplicating the extensive migration logic already present in
> QEMU, this series reuses the generic VFIO migration infrastructure
> (hw/vfio/migration.c). We achieve this by abstracting the hardcoded
> kernel ioctl() and read()/write() calls behind the existing
> VFIODeviceIOOps table, allowing the vfio-user transport to supply its
> own socket-based implementations.
>
> Kernel VFIO transfers device migration data through a dedicated data_fd.
> vfio-user instead uses its already-established UNIX socket. We introduce
> three new wire commands (VFIO_USER_MIG_DATA_READ, VFIO_USER_MIG_DATA_WRITE,
> and VFIO_USER_GET_PRECOPY_INFO) for streaming migration data and querying
> pre-copy information. The protocol documentation and dirty-page logging
> behaviors are updated accordingly.
>
> The corresponding SPDK device-side implementation is available as a WIP
> series:
>
> https://review.spdk.io/q/topic:vfio-user-live-migration-v2
>
> Current limitations:
> 1. Peer-to-Peer (P2P) migration states are not currently supported by
> the libvfio-user server, so P2P support is not included.
> 2. Device state pre-copy is not yet supported over vfio-user. This
> series explicitly strips the PRE_COPY bit from the advertised
> migration flags, forcing the generic migration code to execute a
> standard stop-and-copy migration.
> 3. Backward migration to older QEMU versions is not explicitly handled
> with compat properties in this series, as older destination binaries
> lack the underlying capability to receive the vfio-user migration
> state.
>
> Changes in v2:
> - Use vfio_device_get_feature() for migration device-feature operations.
> - Add a guarded vfio_device_reset() wrapper and route all reset callers
> through it.
> - Add guarded wrappers for get_precopy_info, mig_data_read, and
> mig_data_write_from_file, and route their callers through them.
> - Preserve the separation between capabilities and callbacks in the
> kernel VFIODeviceIOOps initializer.
>
> v1:
> https://lore.kernel.org/qemu-devel/20260903130833.1437632-1-hugo.komatsu@nutanix.com/
>
> Hugo Komatsu (7):
> docs/vfio-user: clarify data_fd and DMA logging behaviors
> vfio: route device_feature through io_ops
> vfio: route device_reset through io_ops
> vfio: use io_ops abstraction for migration related ioctls
> vfio-user: enable DMA logging for dirty page tracking
> vfio-user: implement mig_data read/write socket operations
> vfio-user: enable live migration for pci devices
I just received :
Dear sender,
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Is someone taking over this series ?
Thanks,
C.