"Maciej S. Szmigiero" <m...@maciej.szmigiero.name> writes:
> From: "Maciej S. Szmigiero" <maciej.szmigi...@oracle.com>
>
> 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.
>
> Signed-off-by: Maciej S. Szmigiero <maciej.szmigi...@oracle.com>
Reviewed-by: Fabiano Rosas <faro...@suse.de>
Out of curiosity, what do you see as a blocker for migrating to a file?
We would just need to figure out a mapping from file offset some unit of
data to be able to write in parallel like with ram (of which the page
offset is mapped to the file offset).
> ---
> include/migration/misc.h | 1 +
> migration/multifd-device-state.c | 7 +++++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/include/migration/misc.h b/include/migration/misc.h
> index 7266b1b77d1f..189de6d02ad6 100644
> --- a/include/migration/misc.h
> +++ b/include/migration/misc.h
> @@ -114,5 +114,6 @@ void dirty_bitmap_mig_init(void);
> /* migration/multifd-device-state.c */
> bool multifd_queue_device_state(char *idstr, uint32_t instance_id,
> char *data, size_t len);
> +bool migration_has_device_state_support(void);
>
> #endif
> diff --git a/migration/multifd-device-state.c
> b/migration/multifd-device-state.c
> index c9b44f0b5ab9..7b34fe736c7f 100644
> --- a/migration/multifd-device-state.c
> +++ b/migration/multifd-device-state.c
> @@ -11,6 +11,7 @@
> #include "qemu/lockable.h"
> #include "migration/misc.h"
> #include "multifd.h"
> +#include "options.h"
>
> static QemuMutex queue_job_mutex;
>
> @@ -97,3 +98,9 @@ bool multifd_queue_device_state(char *idstr, uint32_t
> instance_id,
>
> return true;
> }
> +
> +bool migration_has_device_state_support(void)
> +{
> + return migrate_multifd() && !migrate_mapped_ram() &&
> + migrate_multifd_compression() == MULTIFD_COMPRESSION_NONE;
> +}
