Re: Ping: [PATCH] Qemu: migration: Not bind RAM info with active migration status

On Tue, Jan 05, 2021 at 09:28:27PM +0800, Keqian Zhu wrote: > Hi Daniel, > > Thanks for your reply :-) Please see my words below. > > On 2021/1/4 19:58, Daniel P. Berrangé wrote: >> On Fri, Dec 18, 2020 at 04:38:22PM +0800, Keqian Zhu wrote: >>> Hi Daniel and Jiri, >>> >>> On 2020/12/8 18:31, Jiri Denemark wrote: >>>> On Tue, Dec 08, 2020 at 09:27:39 +0000, Daniel P. Berrangé wrote: >>>>> On Tue, Dec 08, 2020 at 10:06:25AM +0800, zhukeqian wrote: >>>>>> >>>>>> On 2020/12/7 18:38, Daniel P. Berrangé wrote: >>>>>>> On Mon, Dec 07, 2020 at 09:55:53AM +0800, zhukeqian wrote: >>>>>>>> Hi Daniel, >>> [...] >>> >>>>>> >>>>>> Hi Daniel, >>>>>> >>>>>> The purpose is to remove this failure check for QEMU v2.12. >>>>>> In QEMU commit 65ace0604551, it decoupled the RAM status from the active migration status. >>>>>> >>>>>> The usage scenario is querying migration status at destination side, which may contain >>>>>> active migration status, but without RAM status, so we will see that libvirt report error here. >>>>> >>>>> I'm confused, because AFAIK, libvirt does not need to run >>>>> query-migrate on the destination, so there shouldn't be anything >>>>> that needs fixing. >>>> >>>> Moreover, you can't even request migration statistics on the destination >>>> manually because libvirt blocks that: >>>> >>>> # virsh domjobinfo nest >>>> error: Operation not supported: migration statistics are available only >>>> on the source host >>>> >>>> Jirka >>>> >>>> . >>>> >>> Sorry for delay reply. >>> >>> The purpose of QEMU commit 65ace0604551 (migration: add postcopy total blocktime into query-migrate) >>> is to query some postcopy related information on destination side. >>> >>> We can call query-migrate on destination side *after* migration complete, thanks. >> >> But nothing in libvirt ever tries to call query-migrate on the dest >> side. > Yes, but the dest side does not always act as dest. After migration completion, the dest side enters > to a normal status and libvirt does not forbid us to query migration status. > > Before QEMU commit 65ace0604551, we can successfully query the migration status, which is > MIGRATION_STATUS_NONE. But this commit will return valid status (MIGRATION_STATUS_COMPLETED) > without ram info, causing libvirt reports error (migration was active, but no RAM info was set). > >> >> Do you have more patches that add such calls ? If so, then please send a >> patch series that does the full job. > I do not add new feature to libvirt, but just manually execute query-migrate on dest side *after > migration completion* will trigger this problem. How are you running query-migrate ? If you're doing that with monitor command passthrough then we shouldn't need to change the libvirt migration code.

Please can you provide the exact sequence of libvirt API calls / virsh commands you are running on both source and dest to reproduce the problem. Regards, Daniel