On 16/06/2016 20:05, Eduardo Habkost wrote: > On Thu, Jun 16, 2016 at 12:42:19PM +0200, Paolo Bonzini wrote: >> >> >> On 16/06/2016 12:34, Haozhong Zhang wrote: >>> On 06/16/16 12:23, Paolo Bonzini wrote: >>>> >>>> >>>> On 16/06/2016 12:16, Haozhong Zhang wrote: >>>>>> >>>>>>> + has_msr_mcg_ext_ctl = true; >>>>>>> } >>>>>>> >>>>>>> c = cpuid_find_entry(&cpuid_data.cpuid, 0x80000007, 0); >>>>>> >>>>>> Which silicon has LMCE? We may want to enable the property for some CPU >>>>>> models. Apart from this, the patch is pretty much okay. >>>>> >>>>> Skylake-EX >>>> >>>> ... However, all virtual CPUs can use LMCE because the rendez-vous is >>>> done in the host. Is this correct? >>>> >>> >>> Yes, if it does not confuse the guest which sees LMCE available on >>> lower end or earlier CPUs (though I think someone would feel >>> happy). >> >> Yes, that's what I expect too. No confusion, and some happiness. :) >> >>> Or do we add it only to qemu64 and kvm64? >> >> I'm not sure where to add it, actually. :( Let's wait for Eduardo's >> opinion. > > Unfortunately we can't enable it by default to any existing CPU > model, or we break the machine-type-runnability rule > (machine-type version changes in an existing runnable VM > configuration should never make the VM not runnable in the same > host). > > If one day we decide that QEMU as a whole can require a newer > kernel, then we can enable it by default on all CPU models. > > What's the first kernel release where LMCE is enabled in > KVM_X86_GET_MCE_CAP_SUPPORTED, BTW? It will presumably be 4.8. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
