Re: [Qemu-devel] [RFC 0/2] GET_EMULATED_CPUID support with "allow-emulation" option

[Paolo Bonzini]

Il 05/06/2014 18:24, Alexander Graf ha scritto:
> On 05.06.14 18:12, Eduardo Habkost wrote:
> > This implements GET_SUPPORTED_CPUID support using an explicit option
> > for it:
> > "allow-emulation". We don't want any emulated feature to be enabled by
> > accident,
> > so they will be enabled only if the user explicitly wants to allow them.
>
> So is this an all-or-nothing approach? I would really prefer to override
> individual bits.

You can still disable them with "cpu foo,-movbe,allow-emulation".

> Also, I don't think the line "emulated" is the right one to draw. We
> "emulate" SVM or VMX too, but still enable them by default as soon as we
> think they're ready enough.

Well, I disagreed with the whole KVM_GET_EMULATED_CPUID concept for 
MOVBE too for example.  It seemed overengineered to me, sooner or later 
we might graduate MOVBE out of KVM_GET_EMULATED_CPUID as well.

However, for MONITOR/MWAIT it makes some sense.

Paolo