I am using Eric's (Alien Bob) scripts to create qemu and kqemu packages for my new box. Both packages compiled fine (yes, GCC 3.4 is installed ).

Qemu works great, but I cannot get the kqemu accelerator module to load. I receive the following message:

FATAL: Error inserting kqemu (/lib/modules/2.6.21.5/misc/kqemu.ko): Device or resource busy

The module is installed at /lib/modules/2.6.21.5/misc/kqemu.ko.

modules.dep lists the same.

rc.modules is updated as expected from the installation script to load the module at boot.

A manual modprobe results in the same error message.

Any ideas?

Addendum: Do I need to run kqemu when instead I have KVM support enabled directly in the kernel? If kqemu is unnecessary with direct kvm support, then how do I know qemu is using kvm?

Works very fine here. AFAIK the (kernel I'm using) Slack 12.0 generic-smp kernel (I guess that it does not have KVM support). Never heard of needing KVM support for Qemu (but things change and I don't always keep up). Hmm, I built my Qemu not real long ago, but a while back (I see 0.9.1 Qemu listed now rather than the 20070727 that I'm using). Mine works too good to fix it. I'll just keep using mine, thankyou.

root@AB60R:~# lsmod | grep qem
kqemu 123044 0


root@AB60R:~# cat /etc/lilo.conf
<snipped>
# Linux bootable partition config begins
image = /boot/vmlinuz-generic-smp-2.6.21.5-smp
initrd = /boot/initrd.gz
root = /dev/sda3
label = generic-smp
read-only


root@AB60R:/var/log/packages# lsg qem
kqemu-1.3.0pre11_2.6.21.5_smp-i486-1
qemu-20070727-i486-1

--
Alan.

I finally got kqemu to load. I had the following in my modprobe.d options:

options kqemu major=250

That option was from a previous effort last summer to run qemu with a Slackware 11 kernel. I removed that option. The module now loads with no error messages and is listed in lsmod.

However, now when I try to run qemu with the -kernel-kqemu option, qemu never finishes loading my virtual machine. Qemu info (Ctrl-Alt-2) reports kqemu is loaded. Yet no luck getting kqemu working. There are no output errors. I seem to have traded one problem for another.

Getting qemu (or any VM manager) running on my new box is a significant step for me to migrate to Slackware full time. I still need to run Windows for various reasons, but I want to migrate my old Windows box into a VM. I have more or less tested my migration into a VM, but without the accelerator, performance is about the same as my old box. I would expect more with a dual core processor.

I appreciate any help to get qemu running. Thanks.

I'm limited, I learned (probably barely) enough so as to get myself going (on qemu, kqemu).
--

qemu -boot c sda3 ~/images/win2k.qcow -m 1000 -smb ~/ntp -localtime

(Works fine) Useable, very useable -- not super fast but totally useable) That's my command line (Win 2K SP4) (1000 is a gig of ram dedicated to the virtual machine -- my 2.8 GHZ pent IV Northwood CPU box I run all of this on has 4 gigs of ram) (overkill here, ie Win 2K doesn't have to have a gig of ram)

Mine uses kqemu, see further below.

al@AB60R:~$ cat /etc/fstab
/dev/sda5 swap swap defaults 0 0
/dev/sda3 / ext3 defaults 1 1

Slack 12 and my Win 2K image file (win2k.qcow) is on (scsi HD) sda3 (/dev/sda3)

Umm, where did you find (doc of/about) useage of -kernel option?

man qemu

/usr/doc/qemu-20070727/qemu-doc.html

<quote>
Linux boot specific: When using these options, you can use a given Linux kernel without installing it in the disk image. It can be useful for easier testing of various kernels.
`-kernel bzImage'
Use bzImage as kernel image.
</quote>

from that doc, I get that (in order to use the -kernel option) 1. must be launching a Linux (not Win) in the (virtual machine) Qemu *AND* 2. that (-kernel) option makes (the step 1 herein [Linux]) O.S. use the kernel pointed to by -kernel rather than using the kernel that is in the [HD file (image file) (.qcow in my command above)] ie (from doc quote above) "testing of various kernels"

Perhaps your command line to launch Qemu is not yet sufficiently correct (it was one of the hardest things for me) but my Win 2K in virtual mach. accesses my lan and the internet and also a folder named ~/ntp on the host O.S. Slack 12 via the -smb (Samba) option. I got Slack and Win on one box at once both running simultaneously in real time, both access each other, both access the lan and the internet.

Ctrl-Alt-2

(qemu) info kqemu
kqemu support: enabled for user code
(qemu)

How to get back out of this, the qemu monitor? (I don't know how, I entered a "q" which shut it all off and I had to run my above command line again (started the whole thing again) there must be a better way (to get out of the monitor).

Win XP (in Qemu/kqemu) may possibly be a bit on the slow side (for you) (only you will know, after a while).

With the ram I got to dedicate (to Win 2K), vmware workstation, vmware player is faster (than Win 2K in Qemu) (I never got the lan working in vmware though) -- *So*, Qemu is "fast enough" (for my use) and (with Qemu) I have it all ie lan and internet and back and forth file access (smb, samba) between the two O.S.

The later CPU ie dual and quad core etc. with KVM or Xen likely would faster for you than Qemu/kqemu (depends on what you need and whether (K)/qemu meets your needs

I've (another box), a dual core, but I need more around toit's (I want to but I'm yet to) experiment with KVM and Xen.

--
Alan.

http://wiki.archlinux.org/index.php/Qemu

According that, I'm running one of the fastest of the Win O.S. (Win 2K) on Qemu.

http://www.google.com/linux?q=qemu+command+options&btnG=Search&hl=en


--
Alan.

I want to post a follow-up to my original post.

I don't know exactly what I did but now the -kernel-kqemu option loads okay. Yet I'm still puzzled because I see no improvement in speed. Running info kqemu indicates that kqemu is loaded.

I don't have any Windows benchmark testing packages installed to report an actual difference, but my eyeball report is that kqemu is not improving the speed. My 400 MHz K6-III+ running Windows NT4 (SP6a) is a tad faster than running the same OS in qemu on my new 2300 MHz dual core BE-2400.

I hope to troubleshoot more during the weekend but I'll appreciate any hints or ideas.

Edit: I'm using Eric's SlackBuild scripts for both kqemu and qemu. I saw no issues when compiling, but perhaps my inexperience missed something.