On Wed, 2017-07-19 at 12:29 +1000, Balbir Singh wrote:
>
> > diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> > b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> > index 6ea4b53..4fb3581b 100644
> > --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> > +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>
On Fri, 2017-07-14 at 11:52 +1000, Benjamin Herrenschmidt wrote:
> There's a somewhat architectural issue with Radix MMU and KVM.
>
> When coming out of a guest with AIL (ie, MMU enabled), we start
> executing hypervisor code with the PID register still containing
> whatever the guest has been
On Fri, 2017-07-14 at 11:21 +0530, Aneesh Kumar K.V wrote:
>
> > There is still an issue with malicious guests purposefully setting
> > the PID register to a value in the host range. Hopefully future HW
> > can prevent that, but in the meantime, we handle it with a pair of
> > kludges:
> >
> >
Benjamin Herrenschmidt writes:
> There's a somewhat architectural issue with Radix MMU and KVM.
>
> When coming out of a guest with AIL (ie, MMU enabled), we start
> executing hypervisor code with the PID register still containing
> whatever the guest has been using.
>
There's a somewhat architectural issue with Radix MMU and KVM.
When coming out of a guest with AIL (ie, MMU enabled), we start
executing hypervisor code with the PID register still containing
whatever the guest has been using.
The problem is that the CPU can (and will) then start prefetching
or