[BUG] kvm-84 segfault

[BUG] kvm-84 segfault

[Sukadev Bhattiprolu]

Distro:
        - Ubuntu 8.04

CPU:
        - Intel(R) Core(TM)2 Duo CPU     T7700  @ 2.40GHz

qemu-system-x86_64:
        - QEMU PC emulator version 0.9.1 (kvm-84), (I Built locally)

Bug:

I had installed distro kvm (for Ubuntu 8.04) and created a guest Fedora10
image. I eventually uninstalled the distro kvm and built kvm-84 myself.
I have been using this kvm-84 and the Fedora10.img for a while with
libvirt (0.6.0) which again, I built locally.

Today when I try to create a new Fedora10 guest image:

        $ qemu-img create -f qcow2 Fedora10.img 10G

        $ sudo qemu-system-x86_64 -hda Fedora10.img -m 1024 -boot d \
                -cdrom Fedora-10-i386-DVD.iso
        Segmentation fault

/var/log/messages shows:

        kernel: [  193.077299] qemu-system-x86[7810]: segfault at 000001a0
                eip b7cd72f5 esp bfd5e0cc error 4

If I remove the 'sudo' it gives "Permission denied" on /dev/kvm, but the
same command works fine (in slow motion).

Pls let me know if I can collect other debug info.

Sukadev

Re: [BUG] kvm-84 segfault

[Amit Shah]

On (Sat) Feb 28 2009 [10:38:41], Sukadev Bhattiprolu wrote:
> 
> Distro:
>         - Ubuntu 8.04
> 
> CPU:
>         - Intel(R) Core(TM)2 Duo CPU     T7700  @ 2.40GHz
> 
> qemu-system-x86_64:
>         - QEMU PC emulator version 0.9.1 (kvm-84), (I Built locally)
> 
> Bug:
> 
> I had installed distro kvm (for Ubuntu 8.04) and created a guest Fedora10
> image. I eventually uninstalled the distro kvm and built kvm-84 myself.
> I have been using this kvm-84 and the Fedora10.img for a while with
> libvirt (0.6.0) which again, I built locally.
> 
> Today when I try to create a new Fedora10 guest image:
> 
>         $ qemu-img create -f qcow2 Fedora10.img 10G
> 
>         $ sudo qemu-system-x86_64 -hda Fedora10.img -m 1024 -boot d \
>                 -cdrom Fedora-10-i386-DVD.iso
>         Segmentation fault
> 
> /var/log/messages shows:
> 
>         kernel: [  193.077299] qemu-system-x86[7810]: segfault at 000001a0
>                 eip b7cd72f5 esp bfd5e0cc error 4

If you can run the same under gdb and give a backtrace, we can say where
it's failing.

> If I remove the 'sudo' it gives "Permission denied" on /dev/kvm, but the
> same command works fine (in slow motion).

You've to add yourself to the 'kvm' group -- adduser <user> kvm. Logout,
login and you don't need sudo to run.

> Pls let me know if I can collect other debug info.
> 
> Sukadev

Amit

Re: [BUG] kvm-84 segfault

[Sukadev Bhattiprolu]

| > /var/log/messages shows:
| > 
| >         kernel: [  193.077299] qemu-system-x86[7810]: segfault at 000001a0
| >                 eip b7cd72f5 esp bfd5e0cc error 4
| 
| If you can run the same under gdb and give a backtrace, we can say where
| it's failing.

Well, to workaround, I had installed the distro kvm and created the Fedora10
guest.  I then uninstalled it and reinstalled my kvm-84 and am not able to
repro the bug now. I will get the gdb backtrace if I run into it again.

Suka