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

From: Juergen Gross
Date: Mon Mar 10 2025 - 11:52:47 EST


On 10.03.25 16:43, Alexey Gladkov wrote:
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) ?


/sys/kvm/ might be a good fit when using KVM?


Juergen

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