Fixing Docker Desktop Startup Issue on Windows 10/11 VM in Proxmox

If you’re running a Windows 10/11 virtual machine (VM) in Proxmox and install Docker Desktop, you might encounter an issue where the VM fails to start and gets stuck on the “startup recovery” screen. This can be caused by nested virtualization not being (fully) enabled in your Proxmox environment.

Solution: Enable Nested Virtualization in Proxmox

To resolve this issue, follow these steps to ensure nested hardware-assisted virtualization is enabled:

1. Check if Nested Virtualization is Enabled

You can check whether nested virtualization is enabled by running the following command on your Proxmox host:

For Intel CPUs:

cat /sys/module/kvm_intel/parameters/nested

For AMD CPUs:

cat /sys/module/kvm_amd/parameters/nested

If the output is N, it means nested virtualization is not enabled. If output is Y, skip to step 3.

2. Enable Nested Virtualization

For Intel CPUs, run:

echo "options kvm-intel nested=Y" > /etc/modprobe.d/kvm-intel.conf

For AMD CPUs, run:

echo "options kvm-amd nested=1" > /etc/modprobe.d/kvm-amd.conf

Then, reload the kernel module:

modprobe -r kvm_intel  # For Intel
modprobe kvm_intel      # For Intel

For AMD:

modprobe -r kvm_amd  # For AMD
modprobe kvm_amd     # For AMD

Check again to confirm:

cat /sys/module/kvm_intel/parameters/nested  # For Intel
cat /sys/module/kvm_amd/parameters/nested    # For AMD

The output should now be Y.

3. Manually Edit the VM Configuration File (If Necessary)

If enabling nested virtualization does not resolve the issue, manually edit the Proxmox VM configuration file.

1. Open a terminal on the Proxmox host.
2. Edit the VM configuration file:
   
   cd /etc/pve/qemu-server/
   cd /etc/pve/qemu-server/
   
   nano [vm-id].conf
   nano [vm-id].conf
3. Add the following line to the configuration file (or append if “args” already exists):
   
   args: -cpu Cooperlake,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time,+vmx
   args: -cpu Cooperlake,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time,+vmx
4. Save the file and reboot the VM.

Step 3 above worked for me with Proxmox VE 8.1.4.