On 04/01/18 15:32, Paolo Bonzini wrote: > On 04/01/2018 16:29, Woodhouse, David wrote: >> Adding that for KVM is in the Linux IBRS patch set that I've seen. >> Didn't we already have a conversation about how the Linux patch set >> does it as an atomically-switched MSR while you've done it manually in >> Xen because it's faster? > I'm also doing it manually in the RHEL versions of the KVM patches, for > what it's worth.
Actually, I did it manually in Xen because I was expecting IBRS on AMD, and there are no MSR load/save lists for PV or SVM guests. (Also yes, I've been reliably informed that manually is much faster than VT-x load/save lists.) ~Andrew
