Re: [PATCH 2/2] KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN

[Vitaly Kuznetsov]

 Igor Mammedov <imammedo@xxxxxxxxxx> writes:

> On Fri, 7 Jan 2022 19:15:43 +0100
> Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
>> On 1/7/22 10:02, Vitaly Kuznetsov wrote:
>> > 
>> > I'm again leaning towards an allowlist and currently I see only two
>> > candidates:
>> > 
>> > CPUID.01H.EBX bits 31:24 (initial LAPIC id)
>> > CPUID.0BH.EDX (x2APIC id)
>> > 
>> > Anything else I'm missing?  
>> 
>> I would also ignore completely CPUID leaves 03H, 04H, 0BH, 80000005h, 
>> 80000006h, 8000001Dh, 8000001Eh (cache and processor topology), just to 
>> err on the safe side.
>
> on top of that,
>
> 1Fh
>

The implementation turned out to be a bit more complex as kvm also
mangles CPUIDs so we need to account for that. Could you give the
attached series a spin to see if it works?

-- 
Vitaly