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Date: Thu, 25 Apr 2024 17:01:28 +0300
Message-Id: <D0T9BM4E1F5C.2TZMIRSHCKCQ2@kernel.org>
To: "Lennart Poettering" <mzxreary@0pointer.de>, "Ard Biesheuvel"
 <ardb@kernel.org>
Cc: "Ilias Apalodimas" <ilias.apalodimas@linaro.org>, "James Bottomley"
 <James.Bottomley@hansenpartnership.com>, "Mikko Rapeli"
 <mikko.rapeli@linaro.org>, <linux-efi@vger.kernel.org>,
 <linux-kernel@vger.kernel.org>, <linux-integrity@vger.kernel.org>
Subject: Re: [PATCH] efi: expose TPM event log to userspace via sysfs
From: "Jarkko Sakkinen" <jarkko@kernel.org>
References: <20240422112711.362779-1-mikko.rapeli@linaro.org>
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In-Reply-To: <ZiopXE6-AucAB9NM@gardel-login>

On Thu Apr 25, 2024 at 12:58 PM EEST, Lennart Poettering wrote:
> General purpose distros typically don't build all TPM drivers into the
> kernel, but ship some in the initrd instead. Then, udev is responsible
> for iterating all buses/devices and auto-loading the necessary
> drivers. Each loaded bus driver might make more devices available for

I've had since day 0 that I've worked with TPM driver (i.e. since 2013
or 2014) that module support should be removed.

I've kept the module compilation only because huge turnback from the
community.

It does not make sense:

1. Because it makes sense as part of "TCB".
2. "TCB" is should in be vmlinux.
3. TPM is also a subsystem with other clients in the kernel.

At minimum the main TPM driver should IMHO just in vmlinux e.g. because
it is rare to see distro kernel with TPM enabled and IMA disabled, I
don't know any.

That said, I would not mind either if TPM subsystem drivers were only
y/n *except* tpm_vtpm_proxy.

BR, Jarkko