Re: [PATCH Part2 v6 14/49] crypto: ccp: Handle the legacy TMR allocation when SNP is enabled

Borislav Petkov
2022-11-22T10:18:08Z

On Mon, Nov 21, 2022 at 06:37:18PM -0600, Kalra, Ashish wrote:
> I agree, but these pages are not in the right state to be released back to

Which pages exactly?

Some pages' state has really changed underneath or you've given the
wrong range?

> It might be a user/sev-guest error, but these pages are now unsafe to use.
> So is a kernel panic justified here, instead of not releasing the pages back
> to host and logging errors for the same.

Ok, there are two cases:

* kernel error: I guess a big fat warning is the least we can issue
here. Not sure about panic considering this should almost never happen
and a warning would allow for people to catch dumps and debug the issue.

* firmware error: I don't think you can know that that is really
the case on a production system without additional fw debugging
capabilities. Dumping a warning would be the least we can do here too,
to signal that something's out of the ordinary and so people can look
into it further.

So yeah, a big fat warning is a good start. And then you don't need any
memory poisoning etc gunk.

--
Regards/Gruss,
Boris.