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dinhngtu

@rniesen Do you mean occasional hangs? Yes, Server 2025 is known to hang if these options are not present.

dinhngtu

@rniesen Your VM is missing Viridian extensions (Hyper-V-compatible VM enlightenments implemented by Xen). This is typically due to the wrong VM template being chosen at the time of creation; the built-in Windows template should be used for all Windows VMs. There's an issue with Server 2025 that causes it to not run well without these features enabled.

Please power off your VM, run this command to add them back, then reboot:

xe vm-param-set uuid=<vm-uuid> platform:viridian=true platform:viridian_time_ref_count=true platform:viridian_reference_tsc=true platform:viridian_apic_assist=true platform:viridian_crash_ctl=true platform:viridian_stimer=true

dinhngtu

@rniesen

Hi,

Could you check the VM's Viridian settings from the host:

xe vm-param-get uuid=... param-name=platform

Followed by checking the Windows BCDEDIT settings:

bcdedit /enum all

yannsionneau

@EddieA Ok, good that your setup is now fully operational !

Let's sort this as a self-resolved problem then for now.
Don't hesitate to ping us again if the issue comes back.

TeddyAstie

@jbamford
Hello, can you give the output of xl info in Dom0 ? If you see hvm_directio in front of virt_caps, then PCI Passthrough is supported (i.e you have VT-d).

You can also check xl dmesg for vt-d specific messages (you can also give the output of it).

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