On Wed, Jan 10, 2018 at 03:28:43PM +0100, Paolo Bonzini wrote: > On 10/01/2018 15:06, Arjan van de Ven wrote: > > On 1/10/2018 5:20 AM, Paolo Bonzini wrote: > >> * a simple specification that does "IBRS=1 blocks indirect branch > >> prediction altogether" would actually satisfy the specification just as > >> well, and it would be nice to know if that's what the processor actually > >> does. > > > > it doesn't exactly, not for all. > > > > so you really do need to write ibrs again. > > Okay, so "always set IBRS=1" does *not* protect against variant 2. Thanks, And what is the point of this "always set IBRS=1" then? Are there some other things lurking in the shadows? > > Paolo
