[PATCH v2] powerpc/powernv: Add ultravisor message log interface

[Michael Ellerman]

Hi Claudio,

Claudio Carvalho <cclaudio at linux.ibm.com> writes:
> Ultravisor (UV) provides an in-memory console which follows the OPAL
> in-memory console structure.
>
> This patch extends the OPAL msglog code to also initialize the UV memory
> console and provide a sysfs interface (uv_msglog) for userspace to view
> the UV message log.
>
> CC: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>
> CC: Oliver O'Halloran <oohall at gmail.com>
> Signed-off-by: Claudio Carvalho <cclaudio at linux.ibm.com>
> ---
> This patch depends on the "kvmppc: Paravirtualize KVM to support
> ultravisor" patchset submitted by Claudio Carvalho.
> ---
>  arch/powerpc/platforms/powernv/opal-msglog.c | 99 ++++++++++++++------
>  1 file changed, 72 insertions(+), 27 deletions(-)

I think the code changes look mostly OK here.

But I'm not sure about the end result in sysfs.

If I'm reading it right this will create:

 /sys/firmware/opal/uv_msglog

Which I think is a little weird, because the UV is not OPAL.

So I guess I wonder if the file should be created elsewhere to avoid any
confusion and keep things nicely separated.

Possibly /sys/firmware/ultravisor/msglog ?

cheers