Re: [PATCH] x86/entry/64: Disallow RDPID in paranoid entry if KVM is enabled

From: Borislav Petkov
Date: Fri Aug 21 2020 - 05:48:10 EST


On Fri, Aug 21, 2020 at 11:44:33AM +0200, Paolo Bonzini wrote:
> It's not like we grab MSRs every day. The user-return notifier restores
> 6 MSRs (7 on very old processors). The last two that were added were
> MSR_TSC_AUX itself in 2009 (!) and MSR_IA32_TSX_CTRL last year.

What about "If it is a shared resource, there better be an agreement
about sharing it." is not clear?

It doesn't matter how many or which resources - there needs to be a
contract for shared use so that shared use is possible. It is that
simple.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette