Re: [Qemu-devel] [PATCH v4 3/3] i386: publish advised value of MSR_IA32_FEATURE_CONTROL via fw_cfg

[Haozhong Zhang]

On 06/20/16 08:56, Paolo Bonzini wrote:
> 
> 
> On 20/06/2016 05:09, Haozhong Zhang wrote:
> > In the current nested VMX implementation in QEMU, setup
> > MSR_IA32_FEATURE_CONTROL is left to guest. So I think, for LMCE which
> > is another feature involving MSR_IA32_FEATURE_CONTROL, we may follow
> > the existing code.
> > 
> > Paolo and Radim, is there any case that objects to setting
> > MSR_IA32_FEATURE_CONTROL in QEMU?
> 
> If the SDM says that the reset state of the MSR is zero, QEMU should
> initialize it to zero.
> 

Yes, SDM says "This MSR is cleared to zero when a logical processor is
reset" (in section "Enabling and Entering VMX operation"), so we
should do so in qemu as well.

Thanks,
Haozhong