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