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Date:   Wed, 30 Sep 2020 06:24:52 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     "Daniel P. Smith" <dpsmith@apertussolutions.com>
Cc:     Ross Philipson <ross.philipson@oracle.com>,
        linux-kernel@vger.kernel.org, x86@kernel.org,
        iommu@lists.linux-foundation.org, linux-integrity@vger.kernel.org,
        linux-doc@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com,
        bp@alien8.de, hpa@zytor.com, luto@amacapital.net,
        trenchboot-devel@googlegroups.com
Subject: Re: [PATCH 05/13] x86: Add early TPM1.2/TPM2.0 interface support for
 Secure Launch
Message-ID: <20200930032452.GA880758@linux.intel.com>
References: <1600959521-24158-1-git-send-email-ross.philipson@oracle.com>
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 <20200925054313.GB165011@linux.intel.com>
 <bf1d8df9-ec79-2cc6-534f-ce1f0a58f123@apertussolutions.com>
 <20200930031952.GA880396@linux.intel.com>
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On Wed, Sep 30, 2020 at 06:19:57AM +0300, Jarkko Sakkinen wrote:
> On Tue, Sep 29, 2020 at 07:47:52PM -0400, Daniel P. Smith wrote:
> > TrenchBoot's AMD Secure Loader (LZ). The former is not well supported
> > and the latter will be getting maintenance under TB. While this is not
> > preferred, we had to weigh this versus trying to convince you and the
> > other TPM driver maintainers on a significant refactoring of the TPM
> > driver. It was elected for the reuse of a clean implementation that can
> > be replaced later if/when the TPM driver was refactored. When we
> > explained this during the RFC and it was not rejected, therefore we
> > carried it forward into this submission.
> 
> What does it anyway mean when you say "RFC was not rejected"? I don't
> get the semantics of that sentence. It probably neither was ack'd,
> right? I do not really care what happened with the RFC. All I can say
> is that in the current state this totally PoC from top to bottom.
> 
> > > How it is now is never going to fly.
> > 
> > We would gladly work with you and the other TPM maintainers on a
> > refactoring of the TPM driver to separate core logic into standalone
> > files that both the driver and the compressed kernel can share.
> 
> Yes, exactly. You have to refactor out the common parts. This is way too
> big patch to spend time on giving any more specific advice. Should be in
> way smaller chunks. For (almost) any possible, this is of unacceptable
                                               ^ " patch"
> size.
> 
> I think that it'd be best first to keep the common files in
> drivers/char/tpm and include them your code with relative paths in the
> Makefile. At least up until we have clear view what are the common
> parts.
> 
> You might also want to refactor drivers/char/tpm/tpm.h and include/linux
> TPM headers to move more stuff into include/linux.
> 
> If you are expecting a quick upstreaming process, please do not. This
> will take considerable amount of time to get right.

/Jarkko