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

From: Jürgen Groß
Date: Tue Mar 11 2025 - 06:23:05 EST


On 11.03.25 10:43, Joerg Roedel wrote:
On Mon, Mar 10, 2025 at 04:43:59PM +0100, Alexey Gladkov wrote:
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) ?

Okay, so let's not mix things up too much here. The only (upstream) case
where Linux _is_ the hypervisor is when running KVM guests. What
information needs to be provided for this case in SYSFS that is not
already provided elsewhere, e.g. by the KVM modules or, in case of SEV,
by /dev/sev? What does Intel expose for TDX?

Back to the guest-side, I agree with introducing a new directory in
SYSFS with sub-directories for each detected hypervisor. To maximise
confusion, it can be called '/sys/hypervisors/', or just /sys/guest/ (as
Boris suggested).

I can live with that, as long as we make it possible to make e.g.
/sys/guest/xen a link to /sys/hypervisor (if xen is the hypervisor
the guest is directly running on). This means that /sys/guest/*/type
should not conflict with /sys/hypervisor/type.


Juergen

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