When running XenServer 7.3-7.5 On AMD EPYC (HPE DL385 Gen10) I cannot boot MxGPU setup using S7150x2 cards
Now, yes, HCL does not show DL385 Gen supported, but shows EPYC supported
I did the same setup on my ThreadRipper 1950x and have same issues

When I run xl dmesg I see the following

(XEN) AMD-Vi: Error initialization
(XEN) I/O virtualisation disabled

Yes BIOS on both HPE server and my Test rig have all AMD-V features enabled
Anyone no why Xen is not able to use IOMMU on AMD Epyc or Ryzen?