VirtualBox 6/7 will not run a client VM on Dell R7625 server (AMD processor)

[Robert Evans]

I have a Dell R7625 with a AMD EPYC 9124 3.0GHz, 16C/32T, 64M Cache (200W) DDR5-4800 processor.

I have tried both Ubuntu 22.04 and Rocky 9.3 as a host OS. In both cases, the VirtualBox GUI starts, but any attempt to start a VM hangs immediately, even before booting. This exhibits this behavior both with saved VMs and trying to do completely new installs. I even tried creating a VM without a VDI disk (recommended by forum) and it till won't start. When you click on "start" it says it is starting the VM, and the status of the VM shifts to "running", but a small black window appears and that is it, there is no interaction possible after that occurs. Logs do not show any obvious errors (forum has reviewed them). I am trying to start an Ubuntu 22.04 client, but again the client window never even gets to the point of trying to boot from the iso, so it does not appear to be client-OS related.

[Robert Evans]

Log file for attempt to start client, this example has no VDI hard disk as the forum recommended trying without one.

[Robert Evans]

Log file of attempt to start client with VDI (did not close out client before generating log)

[Robert Evans]

Just realized that I didn't specify that the two logs generated were on the Rocky 9.3 host.

[fth0]

In the test2.log file, I've noticed the following:

AFAICS, the virtual hardware was initialized without any obvious error message in the log. According to the GMM statistics, the 16 GB configured RAM were reserved, and a small amount of ~800 kB were allocated. The vCPUs didn't execute a single CPU instruction and were all still standing at the BIOS reset vector. The TM statistics for vCPU0 indicate cNsTotal ~180 s, cNsExecuting ~90 s, cNsOther ~90 s, but cPeriodsExecuting ~200 millions!

PS: Corresponding forum thread: ​VirtualBox 6/7 will not run on Dell R762

[thomasah]

I just discovered that the Linux kernel boot parameter "no5lvl" works around this issue! (5-level paging has been introduced to AMD in Zen 4, our new AMD EPYC 9334 with Supermicro mainboard suffered from the same issue)