amd_iommu: report x2APIC support to the operating system

amd_iommu: report x2APIC support to the operating system

This commit adds XTSup configuration to let user choose to whether enable
this feature or not. When XTSup is enabled, additional bytes in IRTE with
enabled guest virtual VAPIC are used to support 32-bit destination id.

Additionally, this commit exports IVHD type 0x11 besides the old IVHD type
0x10 in ACPI table. IVHD type 0x10 does not report full set of IOMMU
features only the legacy ones, so operating system (e.g. Linux) may only
detects x2APIC support if IVHD type 0x11 is available. The IVHD type 0x10
is kept so that old operating system that only parses type 0x10 can detect
the IOMMU device.

Besides, an amd_iommu-stub.c file is created to provide the definition for
amdvi_extended_feature_register when CONFIG_AMD_IOMMU=n. This function is
used by acpi-build.c to get the extended feature register value for
building the ACPI table. When CONFIG_AMD_IOMMU=y, this function is defined
in amd_iommu.c.

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Message-Id: <20240111154404.5333-7-minhquangbui99@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>