[Software] KVM/QEMU under Kubuntu 26.04 failed

[andy001]

On Kubuntu 26.04, I can’t install a Windows 11 VM using KVM/QEMU. As soon as the Windows prompt appears saying “Press any key to boot from CD or DVD…”, the installation freezes.
There were no issues with the 1:1 procedure on 25.10

[claydoh]

It is installing fine here using the version 25H2 iso I have, using virt-manager.

[oshunluvr]

I used this guide recently: https://sysguides.com/install-windows-11-on-kvm

[INVICTRA]

I encountered this exact same issue on my fresh install of Kubuntu 26.04. Creating a VM as always for Windows 11. It hangs after I press any key to enter SETUP.

The problem happens with the Windows 11 64x.iso
It was created with the Windows media creation tool.

What worked for me was to change the ISO for the one claydoh suggested. Win11_25H2_English_x64_v2.iso
Its the 3th option to directly download a ISO from Microsoft.

[oshunluvr]

So I am bginning to migrate to Kubuntu 26.04 from KDEneon. Today I moved all my VMs to the Kubuntu install and all work EXCEPT Windows 11. The error message in the log is:

$ sudo cat /var/log/swtpm/libvirt/qemu/win11-swtpm.log
Starting vTPM manufacturing as swtpm:swtpm @ Wed 06 May 2026 01:09:06 PM EDT
Apply profile: {"Name": "default-v1"}
SWTPM_NVRAM_StoreData: Error (fatal) opening /var/lib/libvirt/swtpm/f8c87363-9b1b-4b2c-8f12-d60290293f97/tpm2/TMP2-00.permall for write failed, Permission denied
SWTPM_NVRAM_Lock_Dir: Could not open lockfile: Permission denied
swtpm process terminated unexpectedly.
Could not start the TPM 2.
An error occurred. Authoring the TPM state failed.
Ending vTPM manufacturing @ Wed 06 May 2026 01:09:06 PM EDT
Starting vTPM manufacturing as swtpm:swtpm @ Wed 06 May 2026 01:26:32 PM EDT
Apply profile: {"Name": "default-v1"}
SWTPM_NVRAM_StoreData: Error (fatal) opening /var/lib/libvirt/swtpm/1703267c-c606-489f-9238-90793a17bc7e/tpm2/TMP2-00.permall for write failed, Permission denied
SWTPM_NVRAM_Lock_Dir: Could not open lockfile: Permission denied
swtpm process terminated unexpectedly.
Could not start the TPM 2.
An error occurred. Authoring the TPM state failed.
Ending vTPM manufacturing @ Wed 06 May 2026 01:26:32 PM EDT
Starting vTPM manufacturing as swtpm:swtpm @ Wed 06 May 2026 01:39:30 PM EDT
Apply profile: {"Name": "default-v1"}
SWTPM_NVRAM_StoreData: Error (fatal) opening /var/lib/libvirt/swtpm/1703267c-c606-489f-9238-90793a17bc7e/tpm2/TMP2-00.permall for write failed, Permission denied
SWTPM_NVRAM_Lock_Dir: Could not open lockfile: Permission denied
swtpm process terminated unexpectedly.
Could not start the TPM 2.
An error occurred. Authoring the TPM state failed.
Ending vTPM manufacturing @ Wed 06 May 2026 01:39:30 PM EDT

I have tried EVERYTHING I can think of: turned off appamor, changed ownership and permissions of the swtpm folder to wide open, changed the version of the TPM device...

Nothing has helped. I even treid to do a new Windows 11 install and got the same errors above. It simply won't work.

The only non-standard thing I've done is used a sim link to move the /var/lib/libvirt/ folder to a different file system.

[Snowhog]

Might be helpful? Windows 11 QEMU/KVM Installation Guide in Linux Including ...

[INVICTRA]

The only non-standard thing I've done is used a sim link to move the /var/lib/libvirt/ folder to a different file system.

Maybe this really does break the permissions or the security layer just doesn't like this type of file path.

You probably will have to leave /var/lib/libvirt as it was.
Or maybe try bind mount instead of symlink.