On 2012-06-01 18:05, Michael S. Tsirkin wrote: > On Fri, Jun 01, 2012 at 05:54:15PM +0200, Jan Kiszka wrote: >> On 2012-06-01 17:28, Michael S. Tsirkin wrote: >>>>> So I won't object to adding a new API but if we do >>>>> it properly this won't help compatibility :( >>>> >>>> It will as this API does not touch the parts that affect the vmstate >>>> (ie. semantics of irq_count won't change). >>> >>> Yes but irq_count in vmstate is a bug. IMO even if we do >>> not change anything we should ignore irq_count on >>> load and recalculate it from what the devices supply. >> >> I don't disagree. But this will only allow keeping backward migration >> support if we preserve the semantics of current map_irq somewhere - to >> keep the chance of calculating the legacy values for vmsave as well. >> >> Jan > > We don't need to preserve it, right? We can calculate it before > savevm.
We can't calculate it without something like the additional infrastructure I listed. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
