[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 I've found via Google is out-of-date/irrelavant.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.