Re: [PATCH v2] iommu/vt-d: Don't reject nvme host due to scope mismatch

[Jerry Snitselaar]

On Sun Jan 05 20, jimyan wrote:
> On a system with an Intel PCIe port configured as a nvme host device, iommu
> initialization fails with
>
>    DMAR: Device scope type does not match for 0000:80:00.0
>
> This is because the DMAR table reports this device as having scope 2
> (ACPI_DMAR_SCOPE_TYPE_BRIDGE):
>
> but the device has a type 0 PCI header:
> 80:00.0 Class 0600: Device 8086:2020 (rev 06)
> 00: 86 80 20 20 47 05 10 00 06 00 00 06 10 00 00 00
> 10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 86 80 00 00
> 30: 00 00 00 00 90 00 00 00 00 00 00 00 00 01 00 00
>
> VT-d works perfectly on this system, so there's no reason to bail out
> on initialization due to this apparent scope mismatch. Add the class
> 0x06 ("PCI_BASE_CLASS_BRIDGE") as a heuristic for allowing DMAR
> initialization for non-bridge PCI devices listed with scope bridge.
>
> Signed-off-by: jimyan <jimyan@xxxxxxxxx>

Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>