From: Jason Gunthorpe <jgg@ziepe.ca>
To: "Safford, David (GE Global Research, US)" <david.safford@ge.com>
Cc: Matthew Garrett <mjg59@google.com>,
"linux-integrity@vger.kernel.org"
<linux-integrity@vger.kernel.org>,
"jarkko.sakkinen@linux.intel.com"
<jarkko.sakkinen@linux.intel.com>,
"Wiseman, Monty (GE Global Research, US)" <monty.wiseman@ge.com>
Subject: Re: [PATCH] tpm_crb - workaround broken ACPI tables
Date: Fri, 12 Jul 2019 12:06:56 -0300 [thread overview]
Message-ID: <20190712150656.GF27512@ziepe.ca> (raw)
In-Reply-To: <BCA04D5D9A3B764C9B7405BBA4D4A3C035EF7E2A@ALPMBAPA12.e2k.ad.ge.com>
On Fri, Jul 12, 2019 at 12:41:58PM +0000, Safford, David (GE Global Research, US) wrote:
>
> > The issue is that the CRB region is mapped into a region marked as ACPI NVS.
> > drivers/acpi/nvs.c claims this region and as a result a resource conflict is
> > generated. Since Windows is clearly fine with other drivers using ACPI NVS
> > regions, the correct fix involves figuring out a way to either share these
> > resources or allow tpm_crb to reclaim the region from the NVS driver. Note
> > that the NVS driver's behaviour is to save and restore NVS regions over
> > suspend/resume, so simply forcibly allocating the resource will result in two
> > separate codepaths touching the region on resume - this seems like a bad
> > outcome.
I wonder if the CRB in the nvs actually needs to be save/restored in
AMD's implementation?
Sounds like the answer is to have TPM CRB somehow detect NVS and
acquire the resource from it, while somehow sequencing suspend/resume
properly.
Jason
next prev parent reply other threads:[~2019-07-12 15:07 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-11 12:29 [PATCH] tpm_crb - workaround broken ACPI tables Safford, David (GE Global Research, US)
2019-07-11 14:10 ` Jarkko Sakkinen
2019-07-11 14:58 ` Jason Gunthorpe
2019-07-11 16:44 ` Safford, David (GE Global Research, US)
2019-07-11 18:50 ` Jason Gunthorpe
2019-07-11 19:31 ` Safford, David (GE Global Research, US)
2019-07-11 20:33 ` Matthew Garrett
2019-07-12 12:41 ` Safford, David (GE Global Research, US)
2019-07-12 15:06 ` Jason Gunthorpe [this message]
2019-07-12 15:48 ` Jarkko Sakkinen
2019-07-12 18:24 ` Matthew Garrett
2019-07-12 19:05 ` Safford, David (GE Global Research, US)
2019-07-12 20:36 ` Matthew Garrett
2019-07-14 19:28 ` Safford, David (GE Global Research, US)
2019-07-14 23:48 ` Matthew Garrett
2019-07-15 19:44 ` Matthew Garrett
2019-07-11 19:16 ` Jarkko Sakkinen
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