Re: [PATCH v2 00/17] Multifd 🔀 device state transfer support with VFIO consumer

[Fabiano Rosas <farosas@suse.de>]

"Maciej S. Szmigiero" <mail@maciej.szmigiero.name> writes:

> From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
>
> This is an updated v2 patch series of the v1 series located here:
> https://lore.kernel.org/qemu-devel/cover.1718717584.git.maciej.szmigiero@oracle.com/
>
> Changes from v1:
> * Extended the QEMU thread-pool with non-AIO (generic) pool support,
> implemented automatic memory management support for its work element
> function argument.
>
> * Introduced a multifd device state save thread pool, ported the VFIO
> multifd device state save implementation to use this thread pool instead
> of VFIO internally managed individual threads.
>
> * Re-implemented on top of Fabiano's v4 multifd sender refactor patch set from
> https://lore.kernel.org/qemu-devel/20240823173911.6712-1-farosas@suse.de/
>
> * Moved device state related multifd code to new multifd-device-state.c
> file where it made sense.
>
> * Implemented a max in-flight VFIO device state buffer count limit to
> allow capping the maximum recipient memory usage.
>
> * Removed unnecessary explicit memory barriers from multifd_send().
>
> * A few small changes like updated comments, code formatting,
> fixed zero-copy RAM multifd bytes transferred counter under-counting, etc.
>
>
> For convenience, this patch set is also available as a git tree:
> https://github.com/maciejsszmigiero/qemu/tree/multifd-device-state-transfer-vfio

With this branch I'm getting:

$ QTEST_QEMU_BINARY=./qemu-system-x86_64 ./tests/qtest/migration-test -p /x86_64/migration/multifd/tcp/uri/plain/none
...
qemu-system-x86_64: ../util/thread-pool.c:354: thread_pool_set_minmax_threads: Assertion `max_threads > 0' failed.
Broken pipe


$ ./tests/qemu-iotests/check -p -qcow2 068
...
+qemu-system-x86_64: ../util/qemu-thread-posix.c:92: qemu_mutex_lock_impl: Assertion `mutex->initialized' failed.