Subject: Re: [PATCH] powerpc/iommu: limit number of TCEs to 512 for H_STUFF_TCE hcall

From: Michael Ellerman <[email-masked]>
Date: Wed, 17 May 2023 22:19:40 +1000

Gaurav Batra <[email-masked]> writes:
> Hello Michael,
>
> System test hit the crash. I believe, it was PHYP that resulted in it 
> due to number of TCEs passed in to be >512.

OK. It's always good to spell out in the change log whether it's a
theoretical/unlikely bug, or one that's actually been hit in testing or
the field.

> I was wondering about the Fixes tag as well. But, this interface, in 
> it's current form, is there from the day the file was created. So, in 
> this case, should I mention the first commit which created this source file?

If it really goes back to the origin commit, then it's probably better
to just say so and tag it for stable, rather than pointing to 1da177e4.

I wonder though is there something else that changed that means this bug
is now being hit but wasn't before? Or maybe it's just that we are
testing on systems with large enough amounts of memory to hit this but
which aren't using a direct mapping?

cheers