OPS works well with the OpenVMM VMM from Microsoft.
You'll need to enable uefi for your image:
config.json:
{
"Uefi": true
}
You'll need to download the firmware from https://github.com/microsoft/mu_msvm/releases - it's in the 'FV' folder.
If you don't want to build openvmm from source you can grab a binary from the ci system at https://github.com/microsoft/openvmm/actions/workflows/openvmm-ci.yaml .
To run:
./openvmm --uefi --uefi-firmware MSVM.fd --disk file:/home/myuser/.ops/images/myimage --hv