On Mon, Jul 08, 2019 at 08:11:41AM -0700, Andi Kleen wrote: > > I don't understand a word of that. > > > > Who cares if the LBR MSRs are touched; the guest expects up-to-date > > values when it does reads them. > > This is for only when the LBRs are disabled in the guest. But your Changelog didn't clearly state that. It was an unreadable mess.