From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Matthew Garrett <mjg59@google.com>
Cc: Seunghun Han <kkamagui@gmail.com>,
Matthew Garrett <mjg59@srcf.ucam.org>,
Peter Huewe <peterhuewe@gmx.de>,
"open list:TPM DEVICE DRIVER" <linux-integrity@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86: tpm: Remove a busy bit of the NVS area for supporting AMD's fTPM
Date: Tue, 27 Aug 2019 15:47:07 +0300 [thread overview]
Message-ID: <20190827124707.yhqtaqa4ur6i45h7@linux.intel.com> (raw)
In-Reply-To: <CACdnJutomLNthYDzEc0wFBcBHK5iqnk0p-hkAkp57zQZ38oGPA@mail.gmail.com>
On Mon, Aug 26, 2019 at 10:40:25AM -0700, Matthew Garrett wrote:
> On Mon, Aug 26, 2019 at 1:18 AM Seunghun Han <kkamagui@gmail.com> wrote:
> > To support AMD's fTPM, I removed the busy bit from the ACPI NVS area like
> > the reserved area so that AMD's fTPM regions could be assigned in it.
>
> drivers/acpi/nvs.c saves and restores the contents of NVS regions, and
> if other drivers use these regions without any awareness of this then
> things may break. I'm reluctant to say that just unilaterally marking
> these regions as available is a good thing, but it's clearly what's
> expected by AMD's implementation. One approach would be to have a
> callback into the nvs code to indicate that a certain region should be
> handed off to a driver, which would ensure that we can handle this on
> a case by case basis?
What if E820 would just have a small piece of code just for fTPM's e.g.
it would check the ACPI tree for fTPM's and ignore TPM regions.
/Jarkko
next prev parent reply other threads:[~2019-08-27 12:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-26 8:17 [PATCH] x86: tpm: Remove a busy bit of the NVS area for supporting AMD's fTPM Seunghun Han
2019-08-26 17:40 ` Matthew Garrett
2019-08-27 8:23 ` Seunghun Han
2019-08-27 16:10 ` Matthew Garrett
2019-08-27 16:36 ` Seunghun Han
2019-08-27 17:11 ` Matthew Garrett
2019-08-28 9:36 ` Seunghun Han
2019-08-29 15:34 ` Jarkko Sakkinen
2019-08-29 15:39 ` Jarkko Sakkinen
2019-08-29 16:12 ` Seunghun Han
2019-08-30 10:01 ` Seunghun Han
2019-08-27 12:47 ` Jarkko Sakkinen [this message]
2019-08-27 15:49 ` Seunghun Han
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190827124707.yhqtaqa4ur6i45h7@linux.intel.com \
--to=jarkko.sakkinen@linux.intel.com \
--cc=kkamagui@gmail.com \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mjg59@google.com \
--cc=mjg59@srcf.ucam.org \
--cc=peterhuewe@gmx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox