Comment # 2 on bug 1201632 from Friedrich Haubensak

thanks for your hints.

booting 5.3.18-150300.59.81: neither spectre_v2=retpoline nor spectre_v2=off
make a difference, i.e., qemu guests still do not start up.

NB, after looking at the "related bugs", as far i had access to them:  the host
systems here are running stable with 59.81.  it's starting up the qemu guests
that does not work, i.e., the virtual console window stays completely black and
silent.  and: according to the boot log, 59.76, where qemu guest start up
works, is running  with
Spectre V2 : Mitigation: Retpolines
Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch