Comment 1 for bug 1900113

Hello Nam,

Thank you for the bug report.

Without having the journal log and knowing that the issue is intermittent, I can only guess that this is due to the lack of extra kernel modules available on the system where things break.

$ dpkg -S /lib/modules/4.15.0-122-generic/kernel/drivers/pci/pci-stub.ko
linux-modules-extra-4.15.0-122-generic: /lib/modules/4.15.0-122-generic/kernel/drivers/pci/pci-stub.ko

$ dpkg -l | grep modules-extra | grep 122
ii linux-modules-extra-4.15.0-122-generic 4.15.0-122.124 amd64 Linux kernel extra modules for version 4.15.0 on 64 bit x86 SMP

As a workaround, you could install this package but the real fix would be for us to drop this module.

I found that it is no longer supported by libvirt either way (presumably in favor of VFIO):
https://github.com/libvirt/libvirt/commit/b8e7e9be9a2168648d16417e2442e322a17c44c7