On Wed, May 11, 2022, Maxim Levitsky wrote: > On Thu, 2022-04-14 at 15:19 +0200, Vitaly Kuznetsov wrote: > > +/* > > + * Note, Hyper-V isn't actually stealing bit 28 from Intel, just abusing it by > > + * pairing it with architecturally impossible exit reasons. Bit 28 is set only > > + * on SMI exits to a SMI transfer monitor (STM) and if and only if a MTF VM-Exit > > + * is pending. I.e. it will never be set by hardware for non-SMI exits (there > > + * are only three), nor will it ever be set unless the VMM is an STM. > > I am sure that this will backfire this way or another. Their fault though... Heh, that was my initial reaction too, but after working through the architecture I gotta hand it to the Hyper-V folks, it's very clever :-) And if we ever need a synthetic exit reason for PV KVM... :-)
