iommu/amd: Skip non-IVMD entries when parsing IVRS memory definitions

init_memory_definitions() walks every top-level subtable including the
IVHD blocks (type 0x10/0x11/0x40) in the IVRS ACPI table. It interprets
each one as a 'struct ivmd_header', solely on m->flags, without first
checking that the subtable's type actually is one of the IVMD types
(ACPI_IVMD_TYPE, ACPI_IVMD_TYPE_ALL, ACPI_IVMD_TYPE_RANGE).

    if (m->flags & (IVMD_FLAG_UNITY_MAP | IVMD_FLAG_EXCL_RANGE))
            init_unity_map_range(m, table);

IVMD_FLAG_UNITY_MAP (0x01) occupies the same bit position as the IVHD
flags field's HtTunEn bit. Unlike real hardware, QEMU's AMD IOMMU
emulation sets HtTunEn unconditionally (flags=0xD1 for type 0x10,
0x11 for type 0x11), so every QEMU-emitted IVHD block is misidentified
as a unity-map/exclusion-range IVMD entry, which subsequently results
in the creation of a bogus pci segment. Eg:

    AMD-Vi: PCI segment : 0x4000, last bdf : 0x0000

Fix by checking the subtable's type before treating it as IVMD.

Fixes: be2a022c0dd0 ("x86, AMD IOMMU: add functions to parse IOMMU memory mapping requirements for devices")
Cc: stable@vger.kernel.org
Signed-off-by: Akshay Jindal <Akshay.Jindal@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

0 files changed, 0 insertions, 0 deletions