hw/acpi: Implement the SRAT GI affinity structure

hw/acpi: Implement the SRAT GI affinity structure

ACPI spec provides a scheme to associate "Generic Initiators" [1]
(e.g. heterogeneous processors and accelerators, GPUs, and I/O devices with
integrated compute or DMA engines GPUs) with Proximity Domains. This is
achieved using Generic Initiator Affinity Structure in SRAT. During bootup,
Linux kernel parse the ACPI SRAT to determine the PXM ids and create a NUMA
node for each unique PXM ID encountered. Qemu currently do not implement
these structures while building SRAT.

Add GI structures while building VM ACPI SRAT. The association between
device and node are stored using acpi-generic-initiator object. Lookup
presence of all such objects and use them to build these structures.

The structure needs a PCI device handle [2] that consists of the device BDF.
The vfio-pci device corresponding to the acpi-generic-initiator object is
located to determine the BDF.

[1] ACPI Spec 6.3, Section 5.2.16.6
[2] ACPI Spec 6.3, Table 5.80

Cc: Jonathan Cameron <qemu-devel@nongnu.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Cedric Le Goater <clg@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Message-Id: <20240308145525.10886-3-ankita@nvidia.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>