Re: [Qemu-devel] bug report with kqemu on AMD 64

[Luiz Felipe]

Hi people,

I would like to tank you for your attention and patience. I don't understand many things about emulators, nor linux. I started using Ubuntu-Linux this year, and since then, i started to discover a new world. But sometimes i have some problems and it's not so easy to a newbie to solve it.

But, i don't know exactly why, it happened here that kvm started to work. Yesterday i installed a windows XP SP3 on a new machine image using virt-manager. And since kvm and windows did not want to work together, as happened to virtualbox another day, i tried to install windows using a kqemu mode. Well, today i simply tried to write this in the terminal window: "kvm Windows.img" on the image directory, and it happened for my surprise that kvm could run windows image, and it was much faster than kemu.

So, although i can't guess why it worked for me, the fact is that now it is working, and the problem has been solved. Perhaps in the future i can discover why this have happened. Now, i have a question: I've written to this mail list because qemu message on my terminal told me to do so. So, what is this list about? Is this some list of the community that develops qemu?

In the future, if i discover or understand what happened here for things get working, may i write tothis mail list, or is there any other place where it would be more appropriate to do that?

Thank's


Luiz Felipe

On Tue, Nov 17, 2009 at 4:15 PM, Rick Vernam <address@hidden> wrote:

On Tuesday 17 November 2009 12:11:58 am Luiz Felipe wrote:
> Hi, i tried to use kqemu in ubuntu to start Windows XP SP3. I used the
> command line: "qemu -kernel-kqemu" and the system started to run windows on
> qemu. Although, i observed the following message on my shell:
>
> QEMU acceleration layer not activated: Permission denied
> unknown keycodes `evdev(abnt2)_aliases(qwerty)', please report to
> address@hidden

1 - It has been stated here on the mailing list that kqemu is no longer
supported by Qemu; by no means do I consider myself a qualified spokesman on
the issue (I don't have hardware virtualization support, so I know where
you're coming from).
2 - It's possible that the kqemu issue is only a permissions problem - check
/dev/kqemu and see if you have rw permissions there (for example you might
want to chown root:qemu /dev/kqemu and chmod 0660 /dev/kqemu ... and make sure
you have yourself in the qemu group. maybe you'd have to create that group
first, I really don't know).
3 - I'd guess that the unknown keycode is a separate issue...

>
> My computer is an AMD 64 Phenom quad-core. I had problems with virtualbox
> and kvm. The system crashed. As i've read onsome forums, it appears to be
> some incompatibility between my computr BIOS and the hardware
> virtualization since I've read that kemu emulates everything, and that's
> why it's alower than other virtualization machines.

Yes, qemu by itself emulates everything.  In the past, kqemu provided
virtualization.  KVM now plays that role.

> May the problem experienced with kqemu is been caused by the impossibility
of optimization using hardware?

If you can get qemu to load kqemu, many things will be virtualized resulting
in a noticeable improvement in speed.  (ie, check /dev/kqemu file permissions)

Have you tried using Virtualbox with hardware virtualization (ie VT-x/AMD-V)
turned off?

>
> Thank's.
>
> Luiz Felipe
>