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Date:   Tue, 25 Jan 2022 12:58:52 +0200
From:   Mika Westerberg <mika.westerberg@linux.intel.com>
To:     Bjorn Helgaas <helgaas@kernel.org>
Cc:     Rajat Jain <rajatja@google.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, rajatxjain@gmail.com,
        dtor@google.com, jsbarnes@google.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        Pavel Machek <pavel@denx.de>,
        Oliver O'Halloran <oohall@gmail.com>,
        Joerg Roedel <joro@8bytes.org>
Subject: Re: [PATCH] PCI: ACPI: Allow internal devices to be marked as
 untrusted
Message-ID: <Ye/X7E2dKb+zem34@lahna>
References: <20220120000409.2706549-1-rajatja@google.com>
 <20220121214117.GA1154852@bhelgaas>
 <Ye5GvQbFKo+CFtRb@lahna>
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Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
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On Mon, Jan 24, 2022 at 08:27:17AM +0200, Mika Westerberg wrote:
> > > This patch introduces a new "UntrustedDevice" property that can be used
> > > by the firmware to mark any device as untrusted.
> 
> I think this new property should be documented somewhere too (also
> explain when to use it instead of ExternalFacingPort). If not in the
> next ACPI spec or some supplemental doc then perhaps in the DT bindings
> under Documentation/devicetree/bindings.

Actually Microsoft has similar already:

https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#identifying-internal-pcie-ports-accessible-to-users-and-requiring-dma-protection

I think we should use that too here.