aboutsummaryrefslogtreecommitdiff
path: root/migration/multifd-device-state.c
AgeCommit message (Collapse)AuthorFilesLines
2025-03-06migration: Add save_live_complete_precopy_thread handlerMaciej S. Szmigiero1-0/+92
This SaveVMHandler helps device provide its own asynchronous transmission of the remaining data at the end of a precopy phase via multifd channels, in parallel with the transfer done by save_live_complete_precopy handlers. These threads are launched only when multifd device state transfer is supported. Management of these threads in done in the multifd migration code, wrapping them in the generic thread pool. Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/qemu-devel/eac74a4ca7edd8968bbf72aa07b9041c76364a16.1741124640.git.maciej.szmigiero@oracle.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
2025-03-06migration/multifd: Add multifd_device_state_supported()Maciej S. Szmigiero1-0/+7
Since device state transfer via multifd channels requires multifd channels with packets and is currently not compatible with multifd compression add an appropriate query function so device can learn whether it can actually make use of it. Reviewed-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Link: https://lore.kernel.org/qemu-devel/1ff0d98b85f470e5a33687406e877583b8fab74e.1741124640.git.maciej.szmigiero@oracle.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
2025-03-06migration/multifd: Make MultiFDSendData a structPeter Xu1-5/+0
The newly introduced device state buffer can be used for either storing VFIO's read() raw data, but already also possible to store generic device states. After noticing that device states may not easily provide a max buffer size (also the fact that RAM MultiFDPages_t after all also want to have flexibility on managing offset[] array), it may not be a good idea to stick with union on MultiFDSendData.. as it won't play well with such flexibility. Switch MultiFDSendData to a struct. It won't consume a lot more space in reality, after all the real buffers were already dynamically allocated, so it's so far only about the two structs (pages, device_state) that will be duplicated, but they're small. With this, we can remove the pretty hard to understand alloc size logic. Because now we can allocate offset[] together with the SendData, and properly free it when the SendData is freed. [MSS: Make sure to clear possible device state payload before freeing MultiFDSendData, remove placeholders for other patches not included] Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Acked-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/qemu-devel/7b02baba8e6ddb23ef7c349d312b9b631db09d7e.1741124640.git.maciej.szmigiero@oracle.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
2025-03-06migration/multifd: Device state transfer support - send sideMaciej S. Szmigiero1-0/+118
A new function multifd_queue_device_state() is provided for device to queue its state for transmission via a multifd channel. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Link: https://lore.kernel.org/qemu-devel/ebd55768d3e5fecb5eb3f197bad9c0c07e5bc084.1741124640.git.maciej.szmigiero@oracle.com Signed-off-by: Cédric Le Goater <clg@redhat.com>