[debbugs-tracker] bug#22633: closed (Provide a kvm-less qemu / guix system vm)

[GNU bug Tracking System]

Your message dated Mon, 22 Feb 2016 13:30:21 -0800
with message-id <address@hidden>
and subject line Re: bug#22633: Provide a kvm-less qemu / guix system vm
has caused the debbugs.gnu.org bug report #22633,
regarding Provide a kvm-less qemu / guix system vm
to be marked as done.

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-- 
22633: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=22633
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> --- Begin Message ---
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> Subject: 
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> Provide a kvm-less qemu / guix system vm
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> Date: 
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> Thu, 11 Feb 2016 09:26:12 -0800
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> User-agent: 
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> mu4e 0.9.13; emacs 24.5.1
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>
> So on my Libreboot-enabled machine, KVM does not work.  In fact, even
> starting qemu with KVM enabled on it appears to crash my whole system.
> Not only does "guix system vm" not work, even "guix system vm-image" can
> take the whole machine down!
>
> It would be nice to have a --no-kvm switch, because I'd really like to
> make use of Guix's nice VM features!
>
> PS: Apparently in future revisions of Libreboot, this will be fixed.
>   For now though...
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>
>
> --- End Message ---
> --- Begin Message ---
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> Subject: 
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> Re: bug#22633: Provide a kvm-less qemu / guix system vm
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> Date: 
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> Mon, 22 Feb 2016 13:30:21 -0800
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>
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> User-agent: 
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> mu4e 0.9.13; emacs 24.5.1
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>
>
>
> Ludovic Courtès writes:
>
> > Christopher Allan Webber <address@hidden> skribis:
> >
> >> Christopher Allan Webber writes:
> >>
> >>> Ludovic Courtès writes:
> >>>
> >>>> 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”?
> >>>
> >>> I tried it, and it works!  This does mean that /dev/kvm doesn't exist,
> >>> so I should be able to write a patch to Guix that disables kvm for qemu
> >>> when /dev/kvm is absent.  Great! :)
> >>
> >> This is slightly based off of Leo's preliminary patch, so I included him
> >> in the copyright headers.  I've tested and it works (in terms of
> >> disabling kvm if no /dev/kvm is present) here.
> >
> > Cool!  Can you just double-check whether -enable-kvm has any effect when
> > /dev/kvm is missing?  If it has no effect when /dev/kvm is missing, then
> > we don’t even need a patch.
>
> I checked yes; qemu fails.
>
> >> Let me know if I need to fix something or if I should push...
> >>
> >> From 852e0049213a0a80cacdcad4aba13ab242c3fbd8 Mon Sep 17 00:00:00 2001
> >> From: Christopher Allan Webber <address@hidden>
> >> Date: Mon, 22 Feb 2016 11:23:14 -0800
> >> Subject: [PATCH] vm: Only pass "-enable-kvm" to qemu if /dev/kvm is present.
> >>
> >> * gnu/build/vm.scm (load-in-linux-vm): Only pass "-enable-kvm" flag to qemu
> >>   if "/dev/kvm" is present.
> >> * gnu/system/vm.scm (common-kvm-options): Same as above.
> >
> > [...]
> >
> >> +                   ;; Only enable kvm if we see /dev/kvm exists.
> >> +                   ;; This allows uers without hardware virtualization to 
> >> still use these
> >                                      ^^
> > Typo.
> >
> > [...]
> >
> >> +     ;; Only enable kvm if we see /dev/kvm exists.
> >> +     ;; This allows uers without hardware virtualization to still use these
> >
> > Ditto.
>
> Okay, fixed those.
>
> > Otherwise the patch LGTM.  Make sure to mention:
> >
> >   Fixes <http://bugs.gnu.org/22633>.
> >
> > in the commit log.
>
> Mentioned, committed, pushed!
>
>
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