On 09/22/2016 09:18 AM, Thomas Huth wrote: > On Thu, 22 Sep 2016 07:30:52 +0200 > Thomas Huth <th...@redhat.com> wrote: > >> On Thu, 22 Sep 2016 11:57:15 +1000 >> David Gibson <da...@gibson.dropbear.id.au> wrote: >> >>> On Wed, Sep 21, 2016 at 10:22:11AM +0200, Thomas Huth wrote: >>>> On 20.09.2016 16:39, Cédric Le Goater wrote: >>>>> On 09/20/2016 04:24 PM, Thomas Huth wrote: >>>>>> On 20.09.2016 16:04, Cédric Le Goater wrote: >>>> [...] >>>>>>> There are other issues after in the guest (kernel crashing). But I think >>>>>>> these are related to TM which is not supported in KVM-PR. I am not sure >>>>>>> where we are on that point. >>>>>> >>>>>> There was a patch some months ago: >>>>>> >>>>>> https://lists.gnu.org/archive/html/qemu-ppc/2016-04/msg00046.html >>>>>> >>>>>> ... but I think it has never been included, as far as I can see. >>>>> >>>>> and with that patch, the guest fully boots. But David had some concerns >>>>> on the way it is done. It would be nice to put some cycle on this. >>>> >>>> Looking at the mail thread, I think TM should be currently disabled for >>>> both, KVM-PR and TCG, i.e. only enabled for KVM-HV. The TM support in >>>> TCG is just fake, since TBEGIN always fails. >>> >>> Right. So there's two questions here >>> >>> 1) Is qemu correctly advertising availability of TM in the device >>> tree? >> >> If I've got that right, it's currently always advertising TM, even if >> it's not really available (in TCG mode and PR mode). >> >>> If not we need to fix that, which might involve adding a kernel >>> capability for the PR case. >>> >>> 2) Is the kvm unit test properly checking for availability of TM >>> before executing? >> >> Not yet. That's why it would be good to get a proper way for testing >> for the availability of TM --> i.e. something like Anton's patch. >> >>>> Once we've got proper TM support in TCG, this can be easily changed >>>> within QEMU. And once we've got TM support in KVM-PR, I think we should >>>> also introduce a capability flag to KVM which can be used to inform QEMU >>>> about this. >>>> >>>> So I think Anton's patch currently just lacks the check for TCG. >>>> Anton, if you've got some spare minutes, could you maybe send an updated >>>> version of that patch? >>> >>> Sorry, which patch of Anton's? >> >> This one: >> https://lists.gnu.org/archive/html/qemu-ppc/2016-04/msg00415.html > > Actually, looking at that whole pa-feature code in QEMU, I think > there's some more work to do here: Everything that is not using > mmu_model==POWERPC_MMU_2_06 is automatically getting pa_features_207. > This is sometimes completely wrong, for example when running with > KVM-PR, the mmu_model for POWER7 is POWERPC_MMU_2_06a instead. > Or when running with TCG, I think it's also perfectly legal to run the > pseries machine with a POWER5+ or PPC970 CPU - and we certainly do not > want to use pa_features_207 there. > > So if you like, I can try to come up with a small patch series that > cleans up this mess - and I could also include an updated versions of > Anton's patch there unless he wants to redo the changes on his own...? > > Thomas >
That would be nice. I just gave a quick try on a f24/le kvm-pr running under a f24/le kvm-hv running under powernv. Only your couple of patches plus Anton's are needed to make it work. Thanks, C.
