[gentoo-user] [OT] Any centralized documentation on qemu-kvm?

[gentoo-user] [OT] Any centralized documentation on qemu-kvm?

[Walter Dnes]

  Before anybody asks...
1) VirtualBox manages to do a hard locup on my Intel I3
2) qemu depends on softmmu, which requires gcc 3.x

  So I installed qemu-kvm (different from qemu).  The documentation that
I've found via Google is out-of-date/irrelavant.  I know that there is a
"kvm" command, and typing "qemu{TAB}{TAB}" gives me...

waltdnes@i3 ~ $ qemu
qemu                qemu-io             qemu-system-x86_64
qemu-i386           qemu-kvm            qemu-x86_64
qemu-img            qemu-nbd

  Of the 9 commands, only qemu, qemu-img, and qemu-nbd have man pages.
So RTFM becomes a little harder<G>.  Are there any up-to-date central
locations for qemu-kvm documentation?

-- 
Walter Dnes <waltdnes@waltdnes.org>

[gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[walt]

On 07/13/2010 08:54 PM, Walter Dnes wrote:
>    Before anybody asks...
> 1) VirtualBox manages to do a hard locup on my Intel I3
> 2) qemu depends on softmmu, which requires gcc 3.x
>
>    So I installed qemu-kvm (different from qemu).  The documentation that
> I've found via Google is out-of-date/irrelavant.  I know that there is a
> "kvm" command, and typing "qemu{TAB}{TAB}" gives me...
>
> waltdnes@i3 ~ $ qemu
> qemu                qemu-io             qemu-system-x86_64
> qemu-i386           qemu-kvm            qemu-x86_64
> qemu-img            qemu-nbd
>
>    Of the 9 commands, only qemu, qemu-img, and qemu-nbd have man pages.
> So RTFM becomes a little harder<G>.  Are there any up-to-date central
> locations for qemu-kvm documentation?

Well, wait a sec.  I track both qemu and qemu-kvm from their git repositories
rather than the gentoo packages, so YMMV.

One potentially very confusing thing between the two products is that the
primary command-line program for qemu is (what else?) "qemu", but for qemu-kvm
the primary command-line program is qemu-system-x86_64. (Only 64-bit machines
with hardware virtualization support will run qemu-kmv, AFAIK.)

BUT BEWARE:  both qemu and qemu-kvm supply a file named qemu-system-x86_64, and
they are not at all the same file, so you cannot have both packages installed in
the same --prefix.  (I don't know how gentoo resolves that conflict.)

I install the git version of qemu in /usr/local, and qemu-kvm in /home/wa1ter,
so I have to be careful to type the --prefix when I run one or the other.

qemu-kvm does not supply a command named 'qemu', so there is no name conflict
in that particular case.  If you type 'qemu-system-x86_64', however, you will
get completely different results depending on which package you are actually
executing, so watch it!

AFAICT, the command-line flags for 'qemu' and 'qemu-system-x86_64' are identical
at least for simple stuff, though I never use the super-anal-compulsive flags
for complicated networking/bridging/firewalling stuff, so I can't comment on it.

My impression from experience is that qemu-img is the same for both packages,
but I'm careful anyway to use the matching version, just in case.

For the short term, I'd say you can use the regular qemu docs for looking up what
command-line flags to use with qemu-kvm.  If you find any exceptions, please let
us know.

Re: [gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[Bill Kenworthy]

On Wed, 2010-07-14 at 21:15 -0700, walt wrote:
> On 07/13/2010 08:54 PM, Walter Dnes wrote:
> >    Before anybody asks...
> > 1) VirtualBox manages to do a hard locup on my Intel I3
> > 2) qemu depends on softmmu, which requires gcc 3.x
> >
> >    So I installed qemu-kvm (different from qemu).  The documentation that
> > I've found via Google is out-of-date/irrelavant.  I know that there is a
> > "kvm" command, and typing "qemu{TAB}{TAB}" gives me...
> >
> > waltdnes@i3 ~ $ qemu
> > qemu                qemu-io             qemu-system-x86_64
> > qemu-i386           qemu-kvm            qemu-x86_64
> > qemu-img            qemu-nbd
> >
> >    Of the 9 commands, only qemu, qemu-img, and qemu-nbd have man pages.
> > So RTFM becomes a little harder<G>.  Are there any up-to-date central
> > locations for qemu-kvm documentation?
> 
> Well, wait a sec.  I track both qemu and qemu-kvm from their git repositories
> rather than the gentoo packages, so YMMV.
> 
> One potentially very confusing thing between the two products is that the
> primary command-line program for qemu is (what else?) "qemu", but for qemu-kvm
> the primary command-line program is qemu-system-x86_64. (Only 64-bit machines
> with hardware virtualization support will run qemu-kmv, AFAIK.)
> 
> BUT BEWARE:  both qemu and qemu-kvm supply a file named qemu-system-x86_64, and
> they are not at all the same file, so you cannot have both packages installed in
> the same --prefix.  (I don't know how gentoo resolves that conflict.)
> 
> I install the git version of qemu in /usr/local, and qemu-kvm in /home/wa1ter,
> so I have to be careful to type the --prefix when I run one or the other.
> 
> qemu-kvm does not supply a command named 'qemu', so there is no name conflict
> in that particular case.  If you type 'qemu-system-x86_64', however, you will
> get completely different results depending on which package you are actually
> executing, so watch it!
> 
> AFAICT, the command-line flags for 'qemu' and 'qemu-system-x86_64' are identical
> at least for simple stuff, though I never use the super-anal-compulsive flags
> for complicated networking/bridging/firewalling stuff, so I can't comment on it.
> 
> My impression from experience is that qemu-img is the same for both packages,
> but I'm careful anyway to use the matching version, just in case.
> 
> For the short term, I'd say you can use the regular qemu docs for looking up what
> command-line flags to use with qemu-kvm.  If you find any exceptions, please let
> us know.
> 
> 

Coming in late, if qemu is different to qemu-kvm, what is different
about running "qemu --enable-kvm" - "man qemu", v0.11.1.

As you say, documentation on this stuff is a bit lacking.

BillK

Re: [gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[Walter Dnes]

On Wed, Jul 14, 2010 at 09:15:59PM -0700, walt wrote

> Well, wait a sec.  I track both qemu and qemu-kvm from their git
> repositories rather than the gentoo packages, so YMMV.

[...deletia...]

> qemu-kvm does not supply a command named 'qemu', so there is no name
> conflict in that particular case.

  Gentoo seems to differ...

waltdnes@i3 ~ $ equery belongs `which qemu`
[ Searching for file(s) /usr/bin/qemu in *... ]
app-emulation/qemu-kvm-0.12.4-r1 (/usr/bin/qemu)


-- 
Walter Dnes <waltdnes@waltdnes.org>

[gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[walt]

On 07/15/2010 09:13 PM, Walter Dnes wrote:
> On Wed, Jul 14, 2010 at 09:15:59PM -0700, walt wrote
>
>> Well, wait a sec.  I track both qemu and qemu-kvm from their git
>> repositories rather than the gentoo packages, so YMMV.
>
> [...deletia...]
>
>> qemu-kvm does not supply a command named 'qemu', so there is no name
>> conflict in that particular case.
>
>    Gentoo seems to differ...
>
> waltdnes@i3 ~ $ equery belongs `which qemu`
> [ Searching for file(s) /usr/bin/qemu in *... ]
> app-emulation/qemu-kvm-0.12.4-r1 (/usr/bin/qemu)

Interesting.  Maybe the gentoo packages add a wrapper script to allow
both to be installed in /usr/bin?  Is /usr/bin/qemu a binary, or a script?

Re: [gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[Walter Dnes]

On Fri, Jul 16, 2010 at 05:03:12PM -0700, walt wrote

> Interesting.  Maybe the gentoo packages add a wrapper script to
> allow both to be installed in /usr/bin?  Is /usr/bin/qemu a binary,
> or a script?

waltdnes@i3 ~ $ file /usr/bin/qemu
/usr/bin/qemu: ELF 64-bit LSB executable, x86-64, version 1 (SYSV),
dynamically linked (uses shared libs), for GNU/Linux 2.6.9, stripped

  Definitely looks like a binary.

-- 
Walter Dnes <waltdnes@waltdnes.org>

Re: [gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[Walter Dnes]

  One more question; are there any reasonably up-to-date 32-bit Gentoo
disk images available?  I'm currently looking at qemu-kvm, but I'll take
VMWare/whatever.

-- 
Walter Dnes <waltdnes@waltdnes.org>

Re: [gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[Neil Bothwick]

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On Sat, 17 Jul 2010 01:44:57 -0400, Walter Dnes wrote:

>   One more question; are there any reasonably up-to-date 32-bit Gentoo
> disk images available?  I'm currently looking at qemu-kvm, but I'll take
> VMWare/whatever.

qemu-kvm can use VMware images.


-- 
Neil Bothwick

What is a "free" gift ? Aren't all gifts free?

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Re: [gentoo-user] Re: [OT] Any centralized documentation on qemu-kvm?

[Walter Dnes]

  Finally got the show on the road, with the boot ISO image booting, and
even showing the cute penguin <G>.  A couple of more advanced questions
now that I have an expert on the line...

1) Are multiple "-redir" clauses allowed in the "qemu-kvm" boot command?
I've got port 22 redirected, and can copy files and tunnel various
services over scp/ssh.  Having multiple "-redir" clauses (i.e.
re-mapping various ports) would allow a bit more flexibility.

2) What cpu settings should I use on the guest?  The default is 1 core
of a "QEMU" cpu.  I may go to 2 (The host has 4 cores).  Does
"-march=native" handle it properly, or do I have to "cat /proc/cpuinfo"
and select features that show up in the "flags" line?

-- 
Walter Dnes <waltdnes@waltdnes.org>