Il 20/08/2013 11:26, Benjamin Herrenschmidt ha scritto: > On Tue, 2013-08-20 at 11:22 +0200, Paolo Bonzini wrote: >> >> Uhm... I thought Alex and I were the one who proposed the simple things. >> You _will_ need to do the complicated stuff sooner or later, but it's >> probably early enough now to ignore it. >> >> And I'm not saying this out of love for big cathedrals, but out of >> lessons we learned the hard way for x86 (where we haven't gotten >> everything right yet, either). > > I suppose if RH is going to deploy 3.10 and we aren't going to backport > the multitce patches then there *might* be a case for supporting that > combo specifically... but it's going to be that bad every time we add > a new feature with a kernel counter part or start adding the gazillion > little bits of PAPR that we are still missing ?
Yes. :( Unless you consider pSeries KVM not mature enough to provide a guest ABI (basically supporting live migration only between identical kernels and QEMUs). It would make some sense, for example (mutatis mutandis) Red Hat has a kernel ABI for the "regular" RHEL kernel, but not for the "real-time" RHEL kernel. Paolo