On 04/10/2014 10:10 PM, Alexander Graf wrote: > > On 08.04.14 03:26, Alexey Kardashevskiy wrote: >> On 03/28/2014 12:07 AM, Alexey Kardashevskiy wrote: >>> On 03/27/2014 11:57 PM, Peter Maydell wrote: >>>> On 27 March 2014 12:49, Alexey Kardashevskiy <a...@ozlabs.ru> wrote: >>>>> On 03/27/2014 11:37 PM, Andreas Färber wrote: >>>>>> Am 27.03.2014 03:41, schrieb Alexey Kardashevskiy: >>>>>>> This should prevent the destination guest from misbehaving when >>>>>>> the threads number is different in "-smp" command. >>>>>> Sorry, I don't understand. When migrating, surely -smp needs to be the >>>>>> same on source and destination, so how can they differ? >>>>> >>>>> The idea is that "-smp" does not migrate and if we run source and >>>>> destination guests with different numbers in -smp, we end up with weird >>>>> machine >>>> Yes, so don't do that. As I understand it: >>>> (1) if you don't run QEMU with the exact same command line >>>> and config at both ends then migration won't work >>>> (2) we don't guarantee to detect and cleanly fail if you >>>> don't do (1) >>>> >>>> It would probably be nice if we did detect config mismatches, >>> Yep, we do not send the device tree (as libvirt does). Pure command line >>> matching won't work. >>> >>>> but that seems to me like a problem we should be addressing >>>> more globally than just for one particular config item for >>>> one particular target... >> >> Ok. So. Let's assume I want to implement migration of "-smp" parameters. >> What would be the correct way of doing this in terms of the current QOM >> principles? Thanks. > > You don't. The migration protocol doesn't migrate configuration. If you > want to start to transfer VM configuration (which I'd be all in for), do it > properly and transfer _all_ configuration.
Then what is the purpose of many, many VMSTATE_.*_EQUAL? And I do not want to send configuration by the proposed patch, I want to make sure that the new guest is able to continue. Why exactly is this bad? -- Alexey
