[PATCH 3/3] arm: KVM: Invalidate BTB on guest exit

[Marc Zyngier]

On Sat, 6 Jan 2018 13:35:46 +0000
Ard Biesheuvel <ard.biesheuvel at linaro.org> wrote:

> On 6 January 2018 at 12:09, Marc Zyngier <marc.zyngier at arm.com> wrote:
> > In order to avoid aliasing attacks against the branch predictor,
> > let's invalidate the BTB on guest exit. This is made complicated
> > by the fact that we cannot take a branch before invalidating the
> > BTB.
> >  
> 
> You can't even take an unconditional branch?

Yup.  We certainly have that restriction on arm64, and I assume it is
the same on 32bit.

	M.
-- 
Without deviation from the norm, progress is not possible.