On 8/23/19 9:48 AM, Michael Ellerman wrote:

Hi Claudio,

Hi Michael,

Claudio Carvalho [off-list ref] writes:

quoted

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 <redacted>
CC: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Claudio Carvalho <redacted>
---
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 ?

Yes, makes sense. I will do that.

Currently, the ultravisor memory console DT property is in
/ibm,opal/ibm,opal-uv-memcons. I think we should move it to
/ibm,ultravisor/ibm,uv-firmware/ibm,uv-memcons. What do you think?

Thanks,
Claudio

cheers