Windows 11 VM no longer detects hypervisor, performance issues

[Victor_root]

Hi everyone,

I'm currently running Proxmox VE 8.2.4 with a Windows 11 23H2 VM on a Ryzen 7 3700X. In the past, I always set the CPU option to "host" in the VM's settings. This configuration worked fine: in the Windows Task Manager, I could see the host CPU, and it indicated "Virtual Machine: Yes".

However, for the past two weeks, without any changes to the VM or the Proxmox configuration, I noticed that Windows no longer detects the VM environment in Task Manager. It now shows the host CPU without the "Virtual Machine: Yes" label. This issue is significantly impacting the performance and responsiveness of the VM, and I'm also seeing high CPU usage.

Interestingly, I have a second Proxmox server running version 8.2.2 with a similar Windows 11 VM, and there, the Task Manager still properly shows "Virtual Machine: Yes". The configuration is identical on both servers.

Has there been any change in Proxmox or Windows that could explain this behavior? Or is there something I might need to adjust to restore proper detection of the hypervisor?

Thanks in advance for your help!

 

[_gabriel]

post .conf of your VM into CODE tag.

 

[Victor_root]

#sata5%3A local-lvm%3Avm-102-disk-0,backup=0,size=7504M,ssd=1
agent: 1
bios: ovmf
boot: order=sata0;ide2
cores: 8
cpu: host
efidisk0: Nvme500:vm-102-disk-1,efitype=4m,pre-enrolled-keys=1,size=4M
hostpci0: 0000:0b:00,pcie=1,x-vga=1
machine: pc-q35-8.1
memory: 12288
meta: creation-qemu=8.0.2,ctime=1701707834
name: Windows
net0: virtio=DA:91:8D:92:57:9F,bridge=vmbr0
numa: 0
ostype: win11
sata0: Nvme500:vm-102-disk-2,size=465G,ssd=1
scsihw: virtio-scsi-pci
smbios1: uuid=7ff3dd9c-9u452-4ca9-a3c6-7cb2ca543090
sockets: 1
tpmstate0: Nvme500:vm-102-disk-3,size=4M,version=v2.0
usb0: host=4-1
vga: none
vmgenid: effd0345-1b41-4ace-8b28-8333e9215af3

 

[_gabriel]

is gpu passthrough was active when you saw "virtual machine = yes" ?

 

[_gabriel]

It now shows the host CPU without the "Virtual Machine: Yes" label. This issue is significantly impacting the performance and responsiveness of the VM, and I'm also seeing high CPU usage

Not sure, it's tied.
args: -cpu host,-hypervisor hide "virtual machine = yes" but performance isn't significantly impacted. ( adding ,migratable=no,+invtsc to -cpu arg help a bit)