Re: [RFC PATCH] kvm: Enable -cpu option to hide KVM

[Michael Tokarev <mjt@tls.msk.ru>]

02.06.2014 17:30, Alex Williamson wrote:
> On Mon, 2014-06-02 at 14:32 +0400, Michael Tokarev wrote:
>> 01.06.2014 20:25, Alex Williamson wrote:
>>> The latest Nvidia driver (337.88) specifically checks for KVM as the
>>> hypervisor and reports Code 43 for the driver in a Windows guest when
>>> found.  Removing or changing the KVM signature is sufficient to allow
>>> the driver to load.
>>
>> Hmm.. Why does it do such thing?  Is it in order to prevent the driver
>> to work in a virtualized windows, ie to prevent vga passthough to work?
>>
>> If that's the case, I think it is a lost game.  Because they'll be adding
>> more, cleverer, checks in the next version.
> 
> Then they'll be pissing off more users and driving them to AMD by doing
> so.  In any case, having the ability to hide the hypervisor seems to
> stand on it's own.  What if we want to test whether a guest behavior is
> the result of a paravirtual interface?  What if a user wants to hide the
> hypervisor in order to further reduce the exposure surface to the VM?
> There are reasons beyond an arms race with Nvidia to want a feature like
> this.  Thanks,

You answer as if I were strongly against the change.  I'm not.
What I'm against is about the reasoning.  This way you're just
accepting the arm race.

Thanks,

/mjt