bug#22633: Provide a kvm-less qemu / guix system vm

[Ludovic Courtès]

Christopher Allan Webber <address@hidden> skribis:

> I tried this:
>
>   (operating-system
>     (kernel linux-libre-4.1)
>     (kernel-arguments '("modprobe.blacklist=kvm-intel,kvm"))
>     ...)
>
> The generated Grub configuration looks right:
>
>   menuentry "GNU with Linux-Libre 4.1.17 (alpha)" {
>     search --label --set guix
>     linux 
> /gnu/store/k3l4g22vypwniy0k3f8xha9l8p1s716d-linux-libre-4.1.17/bzImage 
> --root=guix --system=/gnu/store/flq2702dmj6ppqc4iix6xgp0q364yl3l-system 
> --load=/gnu/store/flq2702dmj6ppqc4iix6xgp0q364yl3l-system/boot 
> modprobe.blacklist=kvm-intel,kvm
>     initrd /gnu/store/flq2702dmj6ppqc4iix6xgp0q364yl3l-system/initrd
>   }
>
> Unfortunately, after rebooting into it:
>
>   address@hidden:~$ lsmod | grep kvm
>   kvm_intel             155648  0
>   kvm                   491520  1 kvm_intel
>   address@hidden:~$ ls /dev/kvm
>   /dev/kvm
>
> Not sure why it didn't seem to do anything...

Libkmod honors ‘modprobe.blacklist’ (in ‘kcmdline_parse_result’ in
libkmod-config.c) and eudev passes KMOD_PROBE_APPLY_BLACKLIST
unconditionally in udev-builtin-kmod.c (meaning it honors it too.)

However, there’s a hyphen-vs-underscore issue, I think.  Namely, the
file is called ‘kvm-intel.ko’, but the normalized module name is
‘kvm_intel’, and this is what libkmod expects (commit 5c7dd5a changes
our code to normalize module names similarly.)

Could you try with “modprobe.blacklist=kvm_intel”?

TIA,
Ludo’.