Re: [PATCH] x86/sev: Make SEV_STATUS available via SYSFS

Alexey Gladkov
2025-03-10T15:44:06Z

On Mon, Mar 10, 2025 at 04:33:08PM +0100, Jürgen Groß wrote:
> On 10.03.25 16:11, Borislav Petkov wrote:
> > On Mon, Mar 10, 2025 at 03:50:09PM +0100, Alexey Gladkov wrote:
> >> Am I understand correctly that you and Joerg are proposing
> >>
> >> /sys/guest/tdx/...
> >> /sys/guest/sev/...
> >>
> >> ?
> >>
> >> Which path to use for the host side ?
> >>
> >> For guest: /sys/coco/guest/{tdx,sev}/...
> >> For host: /sys/coco/host/{tdx,sev}/...
> >>
> >> Maybe it would be better to add the "coco" subdirectory or something like
> >> that ?
> >
> > Hmm, so we can do
> >
> > /sys/guest
> >
> > and extend
> >
> > /sys/hypervisor
> >
> > Or we can do what you're suggesting.
> >
> > If we do /sys/coco/host, then we'll have two different places to read HV info.
> >
> > Or we can stick *everything* coco needs in
> >
> > /sys/coco/{sev,tdx}
> >
> > but then it is coco-specific and if other guest types want to put stuff in
> > sysfs, it'll get ugly.
> >
> > So I guess having
> >
> > /sys/guest
> > and
> > /sys/hypervisor
> >
> > kinda keeps it all clean, hierarchy-wise...
> >
> > Right?
>
> Kind of.
>
> /sys/hypervisor is meant to provide data for running under a hypervisor.
>
> It is NOT meant to provide data for running as a hypervisor.
>
> So far when running either under Xen or under z/VM /sys/hypervisor is being
> populated.
>
> I'm not feeling really strong here. I just want to state the status quo.

OK, so I misunderstood.

If in the /sys/hypervisor we have information for guest (for running under
a hypervisor), where do you propose to put the information for the
host-side (for running as a hypervisor) ?

--
Rgrds, legion