"Dr. David Alan Gilbert (git)" <dgilb...@redhat.com> wrote: > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > Activating the block devices causes the locks to be taken on > the backing file. If we're running with -S and the destination libvirt > hasn't started the destination with 'cont', it's expecting the locks are > still untaken.
I will try to change the naming, because we have: - don't activate block device - and we stop calling bdrv_invalidate_cache_all i.e. behind the scenes bdrv_invalidate_cache activates a block device, not bad O:-) > Don't activate the block devices if we're not going to autostart the VM; > 'cont' already will do that anyway. This change is tied to the new > migration capability 'late-block-activate' that defaults to off, keeping > the old behaviour by default. I have read the old discussion, and we have: - current patch (not call bdrv_invalidate_cache() at bottom_handler) - kevin approach: create two commands activate_devices/deactivate_devices and make libvirt use them correctly I am not really sure which one is better, but as the patch author is Dave .... > bz: https://bugzilla.redhat.com/show_bug.cgi?id=1560854 > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > --- > migration/migration.c | 34 +++++++++++++++++++++++++++------- > qapi/migration.json | 6 +++++- > 2 files changed, 32 insertions(+), 8 deletions(-) Reviewed-by: Juan Quintela <quint...@redhat.com> > +# @late-block-activate: If enabled, the destination will not activate block > +# devices (and thus take locks) immediately at the end of > migration. > +# (since 2.13) > +# > # Since: 1.2 > ## > { 'enum': 'MigrationCapability', > 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', > 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', > 'block', 'return-path', 'pause-before-switchover', 'x-multifd', > - 'dirty-bitmaps' ] } > + 'dirty-bitmaps', 'late-block-activate' ] } > > ## > # @MigrationCapabilityStatus: Just wondering, is there a way to enable a capability for 2.13 and newer, and not activate it for older versions? I *think* that this feature should be on in new releases, and off by default with old machine types. But I haven't through long enough to know what needs to be changed. Later, Juan.
