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Date:   Wed, 16 Jun 2021 14:03:05 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Brijesh Singh <brijesh.singh@amd.com>
Cc:     x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
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Subject: Re: [PATCH Part1 RFC v3 11/22] x86/sev: Add helper for validating
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On Wed, Jun 16, 2021 at 06:00:09AM -0500, Brijesh Singh wrote:
> I am trying to be consistent with previous VMGEXIT implementations. If
> the command itself failed then use the command specific error code to
> tell hypervisor why we terminated but if the hypervisor violated the
> GHCB specification then use the "general request termination".

I feel like we're running in circles here: I ask about debuggability
and telling the user what exactly failed and you're giving me some
explanation about what the error codes mean. I can see what they mean.

So let me try again:

Imagine you're a guest owner and you haven't written the SNP code and
you don't know how it works.

You start a guest in the public cloud and it fails because the
hypervisor violates the GHCB protocol and all that guest prints before
it dies is

"general request termination"

How are you - the guest owner - going to find out what exactly happened?

Call support?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette