Re: [PATCH v2 1/3] drivers/s390/char: Add Ultravisor io device

[Steffen Eiden]

On 3/2/22 11:34, Janosch Frank wrote:
> On 2/23/22 15:48, Steffen Eiden wrote:
> > This patch adds a new miscdevice to expose some Ultravisor functions
> > to userspace. Userspace can send IOCTLs to the uvdevice that will then
> > emit a corresponding Ultravisor Call and hands the result over to
> > userspace. The uvdevice is available if the Ultravisor Call facility is
> > present.
> >
> > Userspace is now able to call the Query Ultravisor Information
> > Ultravisor Command through the uvdevice.
> >
> > Signed-off-by: Steffen Eiden <seiden@xxxxxxxxxxxxx>
> > ---
[...]
> > +
> > +config S390_UV_UAPI
> > +    def_tristate y
> > +    prompt "Ultravisor userspace API"
> > +    depends on PROTECTED_VIRTUALIZATION_GUEST
>
> Please drop the dependency.
> We want this to be available to both guest and host as QUI is available 
> in both environments and more calls like this could follow.
>
> We could put an option around the attestation but the savings are not 
> worth the effort.

Makes sense. I will drop the dependency in v3.

Steffen