Re: [PATCH 38/62] x86/sev-es: Handle instruction fetches from user-space

[Andy Lutomirski]

On Fri, Mar 13, 2020 at 2:12 AM Joerg Roedel <jroedel@xxxxxxx> wrote:
>
> On Wed, Feb 12, 2020 at 01:42:48PM -0800, Andy Lutomirski wrote:
> > I realize that this is a somewhat arbitrary point in the series to
> > complain about this, but: the kernel already has infrastructure to
> > decode and fix up an instruction-based exception.  See
> > fixup_umip_exception().  Please refactor code so that you can share
> > the same infrastructure rather than creating an entirely new thing.
>
> Okay, but 'infrastructure' is a bold word for the call path down
> fixup_umip_exception().

I won't argue with that.

> It uses the in-kernel instruction decoder, which
> I already use in my patch-set. But I agree that some code in this
> patch-set is duplicated and already present in the instruction decoder,
> and that fixup_umip_exception() has more robust instruction decoding.
>
> I factor the instruction decoding part out and make is usable for the
> #VC handler too and remove the code that is already present in the
> instruction decoder.

Thanks!

>
> Regards,
>
>         Joerg
>