iommu/vt-d: Don't apply gfx quirks to untrusted devices

[ Upstream commit 67e8a5b18d41af9298db5c17193f671f235cce01 ]

Currently, an external malicious PCI device can masquerade the VID:PID
of faulty gfx devices, and thus apply iommu quirks to effectively
disable the IOMMU restrictions for itself.

Thus we need to ensure that the device we are applying quirks to, is
indeed an internal trusted device.

Signed-off-by: Rajat Jain <rajatja@google.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200622231345.29722-4-baolu.lu@linux.intel.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>