Re: [PATCH] x86/bugs/multihit: Fix mitigation reporting when KVM is not in use

[Dave Hansen]

On 7/14/20 2:04 PM, Pawan Gupta wrote:
>> I see three inputs and four possible states (sorry for the ugly table,
>> it was this or a spreadsheet :):
>>
>> X86_FEATURE_VMX	CONFIG_KVM_*	hpage split  Result	   Reason
>> 	N			x	    x	     Not Affected  No VMX
>> 	Y			N	    x	     Not affected  No KVM
>> 	Y			Y	    Y	     Mitigated	   hpage split
>> 	Y			Y	    N	     Vulnerable
> Thank you.
> 
> Just a note... for the last 2 cases kernel wont know about "hpage split"
> mitigation until KVM is loaded. So for these cases reporting at boot
> will be "Vulnerable" and would change to "Mitigated" once KVM is loaded
> and deploys the mitigation. This is the current behavior.

That's OK with me, because it's actually pretty closely tied to reality.
 You are literally "vulnerable" until you've committed to a mitigation
and that doesn't happen until KVM is loaded.

When are we going to force kvm to be built in, again? ;)