On 3/5/2025 1:52 PM, Michael S. Tsirkin wrote:
On Tue, Mar 04, 2025 at 06:37:47PM +0000, Suravee Suthikulpanit wrote:
The QEMU-emulated AMD IOMMU PCI device is implemented based on the AMD I/O
Virtualization Technology (IOMMU) Specification [1]. The PCI id for this
device is platform-specific.
Currently, the QEMU-emulated AMD IOMMU device is using AMD vendor id and
undefined device id.
undefined?
Therefore, change the vendor id to Red Hat and request a new QEMU-specific
device id.
Won't the drivers fail to load then?
[1]https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/
specifications/48882_IOMMU.pdf
what is this link teaching us? It's a 300 page document. Where to look
in there?
What I am trying to say is that all AMD IOMMU implementations must
adhere to this specification including the QEMU-emulated AMD IOMMU.
Unlike cpu emulation, we don't need to exactly mimic a particular
hardware implementation.
QEMU-emulated AMD IOMMU device can have its own set of features that it
supports. Going forward, we might even have QEMU-specific feature /
behavior. So, we should not be using an existing PCI ID.
Thanks,
Suravee
