Epyc and XenServer 7.X need help (Error AMD-V)

[charged3800z24]

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?

[NEOAethyr]

This isn't going to be of any help.
But I tested it with my 1090t way back when, with an asus ch4f, supposedly having full support...
I found there was no actual support bios wise at all.
It was a farce.

My current board and cpu, the 4930k, and the r4be, didn't have support for it either even though asus had advertised it.
It was only when a half dozen or so went to there forums and complained about it, then they put out a bios that fixed it.

Amd is the cheapo platform, no offence intended.
What you tend to get is stuff advertised but not actually tested or working.
A 1/4 of the boards with the ryzen couldn't even boot linux at the beginning, and not because of lack of kernel support, but because of screwed up resource mappings in the bios.

If the asus x399 is what you have, you need to get to there forums with a quickness and complain about it before a year or 2 is up.
These days you're lucky to get more then a year of support for your board, bios wise.
So if it's borked, you gotta get on it, other it will not get fixed..

One other thing you can check is to see if your bios options are backwards.
Ie, enabled actually means disabled, and vice versa.
One of the last dfi boards was like that when setting up for a buddy.
Couldn't even boot the windows installer because one of the options was backwards, it was an easy fix but stupid.

I really do suspect it's your bios, and asus's awesome quality support lol :\.
I do think you're gonna have to track down the rog forums and complain, I think they're still up, because I got a stupid email from them a little while back about policies term updates.
And good luck man.


Oh btw, I don't know if you know this, but on amd these days you might have to disable certain pstates to prevent it from crashing on ramdom in linux/bsd.
It effects the epyc's too.
You might have luck with that or not, it's just a heads up.