Re: [PATCH v4 1/2] drivers/s390/char: Add Ultravisor io device

[Janosch Frank]

On 5/17/22 10:42, Steffen Eiden wrote:
> On 5/17/22 10:38, Janosch Frank wrote:
> > On 5/10/22 16:47, 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 can call the Retrieve Attestation Measurement
> > > Ultravisor Call using IOCTLs on the uvdevice.
> > >
> > > The uvdevice will do some sanity checks first.
> > > Then, copy the request data to kernel space, build the UVCB,
> > > perform the UV call, and copy the result back to userspace.
> > >
> > > Signed-off-by: Steffen Eiden <seiden@xxxxxxxxxxxxx>
> > > Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> >
> > I'd like to pick this if I'm allowed to fix the two white space problems
> > below.
> I am fine with that.

Thanks, picked

> Thank you.
>
> > > ---
> > >    MAINTAINERS                           |   2 +
> > >    arch/s390/include/asm/uv.h            |  23 ++-
> > >    arch/s390/include/uapi/asm/uvdevice.h |  51 +++++
> > >    drivers/s390/char/Kconfig             |  10 +
> > >    drivers/s390/char/Makefile            |   1 +
> > >    drivers/s390/char/uvdevice.c          | 264 ++++++++++++++++++++++++++
> > >    6 files changed, 350 insertions(+), 1 deletion(-)
> > >    create mode 100644 arch/s390/include/uapi/asm/uvdevice.h
> > >    create mode 100644 drivers/s390/char/uvdevice.c
> >
> > > +#endif  /* __S390_ASM_UVDEVICE_H */
> >
> > There are two spaces between the "endif" and the "/"
> >
> > > diff --git a/drivers/s390/char/Kconfig b/drivers/s390/char/Kconfig
> > > index 6cc4b19acf85..e9b9902abbaf 100644
> > > --- a/drivers/s390/char/Kconfig
> > > +++ b/drivers/s390/char/Kconfig
> > > @@ -100,6 +100,16 @@ config SCLP_OFB
> > >          This option enables the Open-for-Business interface to the s390
> > >          Service Element.
> > [...]
> > > + * uvio_attestation() does a  Retrieve Attestation Measurement
> > > Ultravisor Call.
> >
> > Double space
> >
> > > + * It verifies that the given userspace addresses are valid and
> > > request sizes
> > > + * are sane. Every other check is made by the Ultravisor (UV) and
> > > won't result
> > > + * in a negative return value. It copies the input to kernelspace,
> > > builds the
> > > + * request, sends the UV-call, and copies the result to userspace.
> > > + *