On 21/08/20 11:22, Borislav Petkov wrote: >> Hence the assumption that KVM makes (and has made ever since TSC_AUX was >> introduced. > And *this* is the problem. KVM can't just be grabbing MSRs and claiming > them because it started using them first. You guys need to stop this. If > it is a shared resource, there better be an agreement about sharing it. 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. Paolo
