Re: [Qemu-devel] [PATCH] kvm: fix kvm_set_migration_log() behavior

[Vincent KHERBACHE <vincent.kherbache@inria.fr>]

Le 18/02/2014 17:16, Paolo Bonzini a écrit :
> This patch is not correct, because it introduces another one: if dirty
> logging was enabled on the memory region (kvm_dirty_pages_log_change),
> it will be disabled after migration.

Yes you're right that was my initial goal, I didn't distinguish the two
cases.

> Note that the effects of
> kvm_set_migration_log and kvm_dirty_pages_log_change should be logically
> ORed.

OK, but that's not really the case (see next comment)

> Can you explain better the problem?  I cannot see anything wrong in the
> code, though it is not the clearest. 

The problem is that if dirty logging is enabled by
kvm_set_migration_log(1) it will NOT be disabled by a
kvm_set_migration_log(0).

So, if this behavior is 'normal', kvm_log_global_stop (which call
kvm_set_migration_log) can not be used independently ?

Also, what I don't understand is why kvm_log_global_start/stop and
kvm_log_start/stop are so different: kvm_set_migration_log VS
kvm_dirty_pages_log_change.


Thank you for the support.

Regards,

-- 
Vincent KHERBACHE