On Tue, Feb 03, 2026 at 11:15:12AM +0100, Lukas Straub wrote:
> We only support COLO with the same version on both sides so this is
> not needed anymore.
>
> Reviewed-by: Fabiano Rosas <[email protected]>
> Signed-off-by: Lukas Straub <[email protected]>
Besides squashing with prior patch, another nitpick inline:
> ---
> migration/migration.c | 5 -----
> migration/savevm.c | 8 +-------
> migration/savevm.h | 1 -
> migration/trace-events | 1 -
> 4 files changed, 1 insertion(+), 14 deletions(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index
> 3f3fc5276bb067ae1960e4b675b33208ad641b23..5515be1bf305b40ba0b590136df18a53451872c5
> 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -3496,11 +3496,6 @@ static void *migration_thread(void *opaque)
> qemu_savevm_send_postcopy_advise(s->to_dst_file);
> }
>
> - if (migrate_colo()) {
> - /* Notify migration destination that we enable COLO */
> - qemu_savevm_send_colo_enable(s->to_dst_file);
> - }
> -
> if (migrate_auto_converge()) {
> /* Start RAMBlock dirty bitmap sync timer */
> cpu_throttle_dirty_sync_timer(true);
> diff --git a/migration/savevm.c b/migration/savevm.c
> index
> 413688b75f4bee6cb10878eb51886cf6ba14872d..a3af09616a7bd22194ffba3cfb7cc4cf15fc88e0
> 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -90,7 +90,7 @@ enum qemu_vm_cmd {
> were previously sent during
> precopy but are dirty. */
> MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */
> - MIG_CMD_ENABLE_COLO, /* Enable COLO */
> + MIG_CMD_UNUSED_0, /* Unused since 11.0 */
IMHO it's not "when unused" that matters, but "when it was used, and used
as what" that matters. E.g. if we received this unused command in some
future QEMU debugging session, we can guess where it came from with that info.
Hence, I'd suggest:
MIG_CMD_DEPRECATED_0, /* Prior to 10.2, used as MIG_CMD_ENABLE_COLO
*/
I still think DEPRECATED is better here, as it reminds people we shouldn't
"reuse" it and better be left untouched to catch surprises, where "UNSED"
may imply "you can use it now".
Other than that looks all good, thanks.
> MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */
> MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */
> MIG_CMD_SWITCHOVER_START, /* Switchover start notification */
> @@ -1092,12 +1092,6 @@ static void qemu_savevm_command_send(QEMUFile *f,
> qemu_fflush(f);
> }
>
> -void qemu_savevm_send_colo_enable(QEMUFile *f)
> -{
> - trace_savevm_send_colo_enable();
> - qemu_savevm_command_send(f, MIG_CMD_ENABLE_COLO, 0, NULL);
> -}
> -
> void qemu_savevm_send_ping(QEMUFile *f, uint32_t value)
> {
> uint32_t buf;
> diff --git a/migration/savevm.h b/migration/savevm.h
> index
> 125a2507b7279412bcb0745b95a774874c31c54f..0a1e5bfd1ca125565a4c90c6f31b2f8c94404117
> 100644
> --- a/migration/savevm.h
> +++ b/migration/savevm.h
> @@ -62,7 +62,6 @@ void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f,
> const char *name,
> uint16_t len,
> uint64_t *start_list,
> uint64_t *length_list);
> -void qemu_savevm_send_colo_enable(QEMUFile *f);
> void qemu_savevm_live_state(QEMUFile *f);
> int qemu_save_device_state(QEMUFile *f);
>
> diff --git a/migration/trace-events b/migration/trace-events
> index
> 91d7506634c9f110e8f0b5f9183728058fe6542a..cfd4d58a0f82ec299ca9e8a9260dd3c3a210cece
> 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -37,7 +37,6 @@ savevm_send_ping(uint32_t val) "0x%x"
> savevm_send_postcopy_listen(void) ""
> savevm_send_postcopy_run(void) ""
> savevm_send_postcopy_resume(void) ""
> -savevm_send_colo_enable(void) ""
> savevm_send_recv_bitmap(char *name) "%s"
> savevm_send_switchover_start(void) ""
> savevm_state_setup(void) ""
>
> --
> 2.39.5
>
--
Peter Xu
