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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Thu, 18 Jun 2020 12:14:41 +0300
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Subject: Re: [PATCH 4/4] pci: export untrusted attribute in sysfs
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Rajat Jain <rajatja@google.com>,
        Christoph Hellwig <hch@infradead.org>,
        David Woodhouse <dwmw2@infradead.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
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        Bjorn Helgaas <bhelgaas@google.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Len Brown <lenb@kernel.org>, iommu@lists.linux-foundation.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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        Raj Ashok <ashok.raj@intel.com>,
        "Krishnakumar, Lalithambika" <lalithambika.krishnakumar@intel.com>,
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On Thu, Jun 18, 2020 at 11:36 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Thu, Jun 18, 2020 at 11:12:56AM +0300, Andy Shevchenko wrote:
> > On Wed, Jun 17, 2020 at 10:56 PM Rajat Jain <rajatja@google.com> wrote:
> > > On Wed, Jun 17, 2020 at 12:31 AM Christoph Hellwig <hch@infradead.org> wrote:
> >
> > ...
> >
> > > (and likely call it "external" instead of "untrusted".
> >
> > Which is not okay. 'External' to what? 'untrusted' has been carefully
> > chosen by the meaning of it.
> > What external does mean for M.2. WWAN card in my laptop? It's in ACPI
> > tables, but I can replace it.
>
> Then your ACPI tables should show this, there is an attribute for it,
> right?

There is a _PLD() method, but it's for the USB devices (or optional
for others, I don't remember by heart). So, most of the ACPI tables,
alas, don't show this.

> > This is only one example. Or if firmware of some device is altered,
> > and it's internal (whatever it means) is it trusted or not?
>
> That is what people are using policy for today, if you object to this,
> please bring it up to those developers :)

> > So, please leave it as is (I mean name).
>
> firmware today exports this attribute, why do you not want userspace to
> also know it?
>
> Trust is different, yes, don't get the two mixed up please.  That should
> be a different sysfs attribute for obvious reasons.

Yes, as a bottom line that's what I meant as well.

-- 
With Best Regards,
Andy Shevchenko