Hi everyone and Martin I would like to confirm the conversation we had in regard the possible limitation of firmware auto-select feature that’s been released since v5.20. I recall you saying that there were a lot of issues with auto select and later they shipped it into a Json file , it still didn’t solve all the problems, did it? Is it better to explicitly specify the loader and nvram path than using auto-select ? Just today, I encountered the issue of using firmware=“efi” on libvirt 5.4.0 I am running Ubuntu eoan 19.10, I am wondering how did it happen. Detailed error Error starting domain: internal error: process exited while connecting to monitor: 2020-05-15T14:19:06.033267Z qemu-system-x86_64: -drive file=/usr/share/OVMF/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on: Failed to lock byte 100 Traceback (most recent call last): File "/usr/share/virt-manager/virtManager/asyncjob.py", line 75, in cb_wrapper callback(asyncjob, *args, **kwargs) File "/usr/share/virt-manager/virtManager/asyncjob.py", line 111, in tmpcb callback(*args, **kwargs) File "/usr/share/virt-manager/virtManager/object/libvirtobject.py", line 66, in newfn ret = fn(self, *args, **kwargs) File "/usr/share/virt-manager/virtManager/object/domain.py", line 1279, in startup self._backend.create() File "/usr/lib/python3/dist-packages/libvirt.py", line 1080, in create if ret == -1: raise libvirtError ('virDomainCreate() failed', dom=self) libvirt.libvirtError: internal error: process exited while connecting to monitor: 2020-05-15T14:19:06.033267Z qemu-system-x86_64: -drive file=/usr/share/OVMF/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on: Failed to lock byte 100