You currently need a hyper-v host that is running at least Windows Insider Build 19640 in order to use Epyc with nested virtualization [1]. See if the beta compute driver works[2]. The hyper-v driver for ussuri has release notes[3], so it should be OK, although I haven't personally tried it. Chris Apsey [1] https://github.com/MicrosoftDocs/Virtualization-Documentation/issues/1276 [2] https://www.cloudbase.it/downloads/HyperVNovaCompute_Beta.msi [3] https://docs.openstack.org/releasenotes/compute-hyperv/ussuri.html -----Original Message----- From: Eric K. Miller <emiller@genesishosting.com> Sent: Tuesday, August 4, 2020 1:03 AM To: openstack-discuss@lists.openstack.org Subject: [EXTERNAL] [nova] Hyper-V hosts CAUTION: EXTERNAL SENDER This email originated from an external source. Please exercise caution before opening attachments, clicking links, replying, or providing information to the sender. If you believe it to be fraudulent, contact the AU Cybersecurity Hotline at 72-CYBER (2-9237 / 706-722-9237) or 72CYBER@augusta.edu Hi, I thought I'd look into support of Hyper-V hosts for Windows Server environments, but it looks like the latest cloudbase Windows Hyper-V OpenStack Installer is for Train, and nothing seems to discuss the use of Hyper-V in Windows Server 2019. Has it been abandoned? Is anyone using Hyper-V with OpenStack successfully? One of the reasons we thought we might support it is to provide nested support for VMs with GPUs and/or vGPUs, and thought this would work better than with KVM, specifically with AMD EPYC systems. It seems that when "options kvm-amd nested=1" is used in a modprobe.d config file, Windows machines lock up when started. I think this has been an issue for a while with AMD processors, but thought it was fixed recently (I don't remember where I saw this, though). Would love to hear about any experiences related to Hyper-V and/or nested hypervisor support on AMD EPYC processors. Thanks! Eric