Re: [PATCH] pci-ids.rst: Add Red Hat pci-id for AMD IOMMU device

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, Mar 06, 2025 at 09:11:53AM +0200, Yan Vugenfirer wrote:
> On Wed, Mar 5, 2025 at 8:54 AM Michael S. Tsirkin <mst@redhat.com> 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?
> >
> 
> Windows will not identify the device (it is a dummy device, without driver)
> and SVVP certifications will fail as a result.
> I suggest using ID that is already present in Windows machine.inf:
> VEN_1002&DEV_5A23

 Ven:  Advanced Micro Devices, Inc. [AMD/ATI]
 Dev: RD890S/RD990 I/O Memory Management Unit (IOMMU) 

> VEN_1022&DEV_1419

 Vendor:  Advanced Micro Devices, Inc. [AMD]
 Dev: Family 15h (Models 10h-1fh) I/O Memory Management Unit

Is our implementation semantically a match for the functionality
in either of those real hardware devices ?

We shouldn't use an existing hardware dev ID unless we intend to
emulate its functionality as a precise match.


With regards,
Daniel
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