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virtualization with kvm-84 on slackware 12.2

I'm having some problems with virtualization using kvm-84 on slackware 12.2. I can't seem to install any guest operating system, qemu-system-x86_64 causes a general protection fault as soon as I start any installer. The system has an intel core2 quad cpu, and virtualization is enabled in bios. I run a slightly modified (highmem support) 2.6.27.7-smp kernel.

Here's what I did:

I downloaded kvm-84, compiled and installed it. This created the kvm kernel modules in /lib/modules/2.6.27.7-smp/extra/. I loaded the intel module with modprobe kvm-intel. /dev/kvm was created with root as owner and group. The kvm howto says to run qemu-system using sudo, but I created a kvm group instead and chgrp'd /dev/kvm to that group. I added my user account to the kvm group.

Code:

ls -la /dev/kvm

crw-rw---- 1 root kvm 10, 232 2009-03-26 09:58 /dev/kvm



groups

users floppy audio video cdrom kvm

Then I created an image and started an installer:

Code:

qemu-img create -f qcow image.img 10G

qemu-system-x86_64 -hda image.img -cdrom /path/to/install/iso -boot d -m 512

The install cd image boots, and I can navigate the menu, but when trying to start the installation, qemu-system-x86_64 causes a general protection fault:

Code:

Mar 26 10:06:52 quad kernel: general protection fault: 0000 [#3] SMP

Mar 26 10:06:52 quad kernel: Modules linked in: kvm_intel kvm snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss ppdev lp parport_pc parport fuse usbhid hid nvidia(P) snd_hda_intel uhci_hcd i2c_i801 snd_pcm agpgart i2c_core snd_timer ehci_hcd snd_page_alloc snd_hwdep sky2 thermal processor evdev thermal_sys button snd sg hwmon soundcore reiserfs

Mar 26 10:06:52 quad kernel:

Mar 26 10:06:52 quad kernel: Pid: 3705, comm: qemu-system-x86 Tainted: P      D  (2.6.27.7-smp #1)

Mar 26 10:06:52 quad kernel: EIP: 0060:[<f9365256>] EFLAGS: 00010246 CPU: 0

Mar 26 10:06:52 quad kernel: EIP is at vmx_save_host_state+0x156/0x1a0 [kvm_intel]

Mar 26 10:06:52 quad kernel: EAX: 00000900 EBX: 00000100 ECX: c0000080 EDX: 00000000

Mar 26 10:06:52 quad kernel: ESI: c0000080 EDI: f22d46e0 EBP: eed21e90 ESP: eed21e6c

Mar 26 10:06:52 quad kernel:  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068

Mar 26 10:06:52 quad kernel: Process qemu-system-x86 (pid: 3705, ti=eed20000 task=f3f3c6e0 task.ti=eed20000)

Mar 26 10:06:52 quad kernel: Stack: 00000000 00000000 00000900 00000000 00000800 00000000 f22d46e0 00000000

Mar 26 10:06:52 quad kernel:        f22d46e0 eed21ef0 f938cf70 00000000 00000001 c0578ffc eed21ed0 c014374d

Mar 26 10:06:52 quad kernel:        00000001 00000000 00000001 083c0000 f3f0b500 f22d46e0 c05598a8 f02f0000

Mar 26 10:06:52 quad kernel: Call Trace:

Mar 26 10:06:52 quad kernel:  [<f938cf70>] ? kvm_arch_vcpu_ioctl_run+0x310/0x9f0 [kvm]

Mar 26 10:06:52 quad kernel:  [<c014374d>] ? futex_wake+0xad/0xe0

Mar 26 10:06:52 quad kernel:  [<c017d6c4>] ? kfree+0x14/0xb0

Mar 26 10:06:52 quad kernel:  [<f9387dae>] ? kvm_vcpu_ioctl+0x44e/0x490 [kvm]

Mar 26 10:06:52 quad kernel:  [<c0152e5b>] ? __rcu_process_callbacks+0xb/0x170

Mar 26 10:06:52 quad kernel:  [<f9387960>] ? kvm_vcpu_ioctl+0x0/0x490 [kvm]

Mar 26 10:06:52 quad kernel:  [<c018d97d>] ? vfs_ioctl+0x2d/0x90

Mar 26 10:06:52 quad kernel:  [<c018dc4a>] ? do_vfs_ioctl+0x26a/0x2b0

Mar 26 10:06:52 quad kernel:  [<c01d6d58>] ? cap_file_ioctl+0x8/0x10

Mar 26 10:06:52 quad kernel:  [<c018dce7>] ? sys_ioctl+0x57/0x70

Mar 26 10:06:52 quad kernel:  [<c010325a>] ? syscall_call+0x7/0xb

Mar 26 10:06:52 quad kernel:  =======================

Mar 26 10:06:52 quad kernel: Code: 08 00 00 89 c1 09 d9 89 4d e4 89 d1 09 f1 be 80 00 00 c0 89 4d e8 8b 55 e8 89 f1 89 d0 31 d2 89 45 dc 8b 45 e4 89 55 e0 8b 55 dc <0f> 30 83 87 98 00 00 00 01 83 c4 18 5b 5e 5f 5d c3 b8 08 0c 00

Mar 26 10:06:52 quad kernel: EIP: [<f9365256>] vmx_save_host_state+0x156/0x1a0 [kvm_intel] SS:ESP 0068:eed21e6c

Mar 26 10:06:52 quad kernel: ---[ end trace 3c762b44fdc696cd ]---

Am I doing something wrong? How do I get this working? Install image used was a debian 5 netinst iso, I also tried an ubuntu 8.10 iso I had lying around and the same thing happened.

Did you check that your CPU support Intel VT ? It seems that some Core 2 do but others don't.

You could check on this page or @ http://processorfinder.intel.com/ or simply look at "cat /proc/cpuinfo|grep vmx"'s output.

The CPU should have the "vmx" flag if it is VT-able.

Mine is not :(

PS There is a SlackBuild for kvm-83 @ http://slackbuilds.org (it needs some editing to work with kvm-84 though).

EDIT This post was wrong about flag to check for, edited accordingly.

/proc/cpuinfo shows the vmx flag which should indicate virtualization support. The kvm-intel module seems to load just fine:

Code:

modprobe kvm-intel

lsmod | grep kvm

kvm_intel              47592  2

kvm                  163952  1 kvm_intel

From what I remember you'll be having problems with x86_64-guests when your OS is 32-bit, which Slackware is.
You still should be able to emulate a 64-bit system, but you won't enjoy the benefits which KQEmu or KVM are supposed to give you.
Thus, performance-wise, it would be better to use 32-bit guests.

I may be wrong about this, but that's how I remember it.

In addition to your steps I created a udev rule.

file: /lib/udev/rules.d/65-kvm.rules

Code:

KERNEL=="kvm", NAME="%k", GROUP="kvm", MODE="0660"

Also you might be interested in the Slackbuild for KVM. Just remember to change the version number to 84 in the kvm.SlackBuild file if you go that route.

How it works for me

I have no idea why your getting a seg fault, but I have several kvm virtual machines running on 12.2 with kernel 2.6.29
These are my notes on how to create install and boot them
Also a url which may help

To create an image for KVM
dd if=/dev/zero of=fedora.img bs=1k count=0 seek=16000000

To Install
/usr/bin/qemu-system-x86_64 -localtime -m 1024 -hda /img/fedora.img -cdrom /dev/cdrom -boot d

Or
/usr/bin/qemu-system-x86_64 -localtime -m 1024 -hda /img/winxp.img -cdrom /img/winxp_pro_us.iso -boot d

To boot
/usr/bin/qemu-system-x86_64 -localtime -m 1024 -hda /img/fedora.img -cdrom /dev/cdrom -soundhw es1370

http://alien.slackbook.org/dokuwiki/...slackware:qemu

I also have a kvm group of which I am a member and somewhere along the line a udev rule was created
KERNEL=="kvm", NAME="%k", GROUP="kvm", MODE="0660"
i believe by the slackbuild from sbo

john

Quote:

Originally Posted by reptiler (Post 3488276)

Ah yes, that was the problem, my install images were 64 bit. I got the 32 bit equivalent and it installed without a problem.

Thanks also to Chuck56 and AlleyTrotter for the udev rule, that will make life a little easier.