Re: [PATCH v4] KVM: x86: Fix KVM_GET_CPUID2 ioctl to return cpuid entries count

From: Denis V. Lunev
Date: Mon May 03 2021 - 15:18:14 EST


On 5/3/21 5:54 PM, Paolo Bonzini wrote:
> On 29/04/21 03:00, Sean Christopherson wrote:
>> On Wed, Apr 28, 2021, Valeriy Vdovin wrote:
>>> It's very explicit by the code that it was designed to receive some
>>> small number of entries to return E2BIG along with the corrected
>>> number.
>>
>> LOL, saying KVM_GET_CPUID2 was "designed" is definitely giving the KVM
>> forefathers the benefit of the doubt.
>
> I was going to make a different joke, i.e. that KVM_GET_CPUID2 was
> indeed designed the way Valeriy described, but that design was
> forgotten soon after.
>
> Really, this ioctl has been such a trainwreck that I think the only
> good solution here is to drop it.
>
> Paolo
>

should we discuss KVM_GET_CPUID3 which will work "normally"?

Den