Re: [Qemu-devel] [PATCH] target-i386: Disable CPUID_EXT_MONITOR when KVM is enabled

[Paolo Bonzini]

Il 27/05/2013 15:07, Eduardo Habkost ha scritto:
>> Changing TCG to KVM should not change hardware
>> > if you use "-cpu ...,enforce", so it is right that it fails when
>> > starting with KVM.
>> > 
> Changing between KVM and TCG _does_ change hardware, today (with or
> without check/enforce). All CPU models on TCG have features not
> supported by TCG automatically removed. See the "if (!kvm_enabled())"
> block at x86_cpu_realizefn().

Perhaps (for "-cpu ...,enforce" or check) that's the real bug we have to
fix?

Paolo

> (That's why I argue that we need separate classes/names for TCG and KVM
> modes. Otherwise our predefined models get less useful as they will
> require low-level feature-bit fiddling on the libvirt side to make them
> work as expected.)
>