On 17/09/15 16:27, Borislav Petkov wrote: > On Thu, Sep 17, 2015 at 01:39:26PM +0200, Paolo Bonzini wrote: >> That's not a big deal, that's what *_safe is for. The problem is that >> there are definitely some cases where the *_safe version is not being used. > I mean to do feature checks which assure you that those MSRs are > there so you don't need the safe variants. And that is not always > easy/possible. > There are plenty of non-architectural MSRs in use which don't have feature bits. Xen used to have problems booting when using the masking MSRs when booting virtualised. Nowadays it uses a cpu vendor check and _safe() probe to detect support. ~Andrew -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html