[Qemu-devel] [Bug 595438] Re: KVM segmentation fault, using SCSI+writeback and linux 2.4 guest

[Serge Hallyn]

** Changed in: kvm
       Status: Confirmed => Invalid

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/595438

Title:
  KVM segmentation fault, using SCSI+writeback and linux 2.4 guest

Status in Kernel Virtual Machine:
  Invalid
Status in QEMU:
  Fix Released
Status in qemu-kvm:
  Fix Released
Status in “qemu-kvm” package in Ubuntu:
  Fix Released
Status in “qemu-kvm” source package in Lucid:
  Fix Released
Status in “qemu-kvm” package in Debian:
  Fix Released

Bug description:
  I Use Ubuntu 32 bit 10.04 with standard KVM.
  I have Intel E7600  @ 3.06GHz processor with VMX

  In this system I Run:
  LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin 
QEMU_AUDIO_DRV=none /usr/bin/kvm -M pc-0.12 -enable-kvm -m 256 -smp 1 -name 
spamsender -uuid b9cacd5e-08f7-41fd-78c8-89cec59af881 -chardev 
socket,id=monitor,path=/var/lib/libvirt/qemu/spamsender.monitor,server,nowait 
-monitor chardev:monitor -boot d -drive 
file=/mnt/megadiff/cdiso_400_130.iso,if=ide,media=cdrom,index=2 -drive 
file=/home/mmarkk/spamsender2.img,if=scsi,index=0,format=qcow2,cache=writeback 
-net nic,macaddr=00:00:00:00:00:00,vlan=0,name=nic.0 -net tap,vlan=0,name=tap.0 
-chardev pty,id=serial0 -serial chardev:serial0 -parallel none -usb -vnc 
127.0.0.1:0 -vga cirrus

  .iso image contain custom distro of 2.4-linux kernel based system.
  During install process (when .tar.gz actively unpacked), kvm dead with
  segmentation fault.

  And ONLY when I choose scsi virtual disk and writeback simultaneously.
  But, writeback+ide, writethrough+scsi works OK.

  I use qcow2. It seems, that qcow does not have such problems.

  Virtual machine get down at random time during file copy. It seems,
  when qcow2 file size need to be expanded.

  IMPACT: kvm used with scsi virtual disk and writeback dies with
  segfault.

  FIX: is the inclusion of a patch cherry-picked from upstream which dequeues
  requests before invoking callbacks.  It is at
  
http://bazaar.launchpad.net/~serge-hallyn/ubuntu/lucid/qemu-kvm/fix-scsi-writeback/revision/70

  TO REPRODUCE: See the command above.

  REGRESSION POTENTIAL: this is cherry-picked from upstream, and has been
  tested by the bug reporter with no ill effects.

To manage notifications about this bug go to:
https://bugs.launchpad.net/kvm/+bug/595438/+subscriptions