Re: [PATCH] KVM: X86: Allow userspace to define the microcode version

[Konrad Rzeszutek Wilk]

On Mon, Feb 26, 2018 at 03:51:30PM -0500, Konrad Rzeszutek Wilk wrote:
> On Mon, Feb 26, 2018 at 08:37:11PM +0100, Borislav Petkov wrote:
> > On Mon, Feb 26, 2018 at 09:39:12AM -0500, Konrad Rzeszutek Wilk wrote:
> > > diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> > > index d19e903214b4..87d044ce837f 100644
> > > --- a/arch/x86/kernel/cpu/intel.c
> > > +++ b/arch/x86/kernel/cpu/intel.c
> > > @@ -144,6 +144,13 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
> > >  {
> > >  	int i;
> > >  
> > > +	/*
> > > +	 * We know that the hypervisor lie to us on the microcode version so
> > > +	 * we may as well trust that it is running the correct version.
> > > +	 */
> > > +	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
> > 
> > I guess
> > 
> > 	cpu_has(c, X86_FEATURE_HYPERVISOR)
> > 
> > since we're passing a ptr to the current CPU.
> 
> Ah yes. Let me fix it up and repost.

I've posted it (but I can't seem to find it on LKML). Here it is in this
thread. Also adding ingo + tglrx