NACK: [SRU][Trusty][Xenial][PATCH] Fix for LP:#1764956

[Gavin Guo]

Hi Juerg,

On Wed, Nov 28, 2018 at 11:05 PM Juerg Haefliger
<juerg.haefliger at canonical.com> wrote:
>
> On Mon, 26 Nov 2018 22:55:49 +0800
> Gavin Guo <gavin.guo at canonical.com> wrote:
>
> > Hi Juerg,
> >
> > On Fri, Nov 23, 2018 at 5:14 PM Juerg Haefliger
> > <juerg.haefliger at canonical.com> wrote:
> > >
> > > Thanks for this Gavin!
> > >
> > > I recognize the problem and as discussed yesterday, I need to
> > > investigate some more. It seems we're missing a couple of patches to
> > > make IBRS (and probably IBPB) passthrough work correctly. So rather
> > > than patching this up I prefer to backport the relevant commits.
> > >
> > > After taking a quick peek, it seems we're missing (or at least
> > > partially) the following (from linux-stable):
> > >
> > > fc00dde96099 KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL
> > > e5a83419c957 KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL
> > > 755502f810c6 KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
> > > 7013129a4034 KVM/x86: Add IBPB support
> > >
> > > And probably more plus whatever is needed for our runtime controls
> > > (from your patch).
> >
> > Agree, I'll also look into the patches for future compatibility
> > issues. Thank you for the time looking into this. :)
>
> Gavin, can you test
> https://code.launchpad.net/~juergh/+git/xenial-linux branch lp1764956?

Thank you for the prompt response, please let me spend some time
rebasing the patch and do some experimentation. I'll keep you posted
about the result.

>
> Thanks
> ...Juerg
>
>
> > >
> > >
> > > ...Juerg