[Bug 616064] Re: Broken networking in kvm guests with pcnet driver

Stéphane Graber stgraber at stgraber.org
Fri Sep 7 21:53:38 UTC 2012

** Changed in: bridge-utils (Ubuntu)
       Status: Confirmed => Invalid

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  Broken networking in kvm guests with pcnet driver

Status in “bridge-utils” package in Ubuntu:
Status in “linux” package in Ubuntu:
Status in “qemu-kvm” package in Ubuntu:

Bug description:
  Binary package hint: qemu-kvm

  Some TCP operations receive unexpected reset (RST) packets when executed on the guest.  I can see these RST packets via
  Wireshark but can't explain their source.  This breaks certain (most) networking on the guest.

  I uncovered this when some 'git clone' operations failed with "Broken
  Pipe" in the guests.  I've been able to reproduce the same failures
  using scp and 'svn checkout'.  The failure occurs 80-90% of the time
  and 'svn checkout' seems to be the quickest to fail.  The same
  operations on the host are always successful.

  My setup is a Lucid amd64 host with two guests (Lucid and Hardy, both
  i386, using kvm).  Networking seems to mostly work.  I can maintain
  persistent ssh connections to the guest and some networking operations
  from the guest (ie. ping) never fail.  However, the git-clone/scp/svn-
  checkout operations fail almost all the time.  I've tried this with
  both virtio and e1000 drivers with no difference.

  This may be similar to some of the behavior reported in bug 584048 but
  not the final patch referenced in comment 27.  I built a custon deb
  including the upstream patch for testing and it had no effect.

  $ lsb_release -rd
  Description:	Ubuntu 10.04.1 LTS
  Release:	10.04

  $ apt-cache policy qemu-kvm
    Installed: 0.12.3+noroms-0ubuntu9.2
    Candidate: 0.12.3+noroms-0ubuntu9.2
    Version table:
   *** 0.12.3+noroms-0ubuntu9.2 0
          500 http://us.archive.ubuntu.com/ubuntu/ lucid-updates/main Packages
          100 /var/lib/dpkg/status
       0.12.3+noroms-0ubuntu9 0
          500 http://us.archive.ubuntu.com/ubuntu/ lucid/main Packages

  ProblemType: Bug
  DistroRelease: Ubuntu 10.04
  Package: kvm 1:84+dfsg-0ubuntu16+0.12.3+noroms+0ubuntu9.2
  ProcVersionSignature: Ubuntu 2.6.32-24.39-server
  Uname: Linux 2.6.32-24-server x86_64
  Architecture: amd64
  Date: Tue Aug 10 16:39:24 2010
  InstallationMedia: Ubuntu-Server 10.04 "Lucid Lynx" - Beta amd64 (20100406.1)
   UID        PID  PPID  C    SZ   RSS PSR STIME TTY          TIME CMD
   root     17641     1  1 2174883 1087144 1 15:42 ?      00:00:59 /usr/bin/kvm -S -M pc-0.12 -cpu qemu32 -enable-kvm -m 8192 -smp 8 -name hound-lucid -uuid 0e32438c-cb4d-1eb9-a560-f25c89c1dbf6 -chardev socket,id=monitor,path=/var/lib/libvirt/qemu/hound-lucid.monitor,server,nowait -monitor chardev:monitor -boot c -drive file=/opt/hound-lucid,if=virtio,index=0,boot=on -drive if=ide,media=cdrom,index=2 -net nic,macaddr=52:54:00:61:7e:c0,vlan=0,model=virtio,name=virtio.0 -net tap,fd=59,vlan=0,name=tap.0 -chardev pty,id=serial0 -serial chardev:serial0 -parallel none -usb -vnc -k en-us -vga cirrus
  MachineType: IBM IBM System x3400 M2 Server -[7836AC1]-
  ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-24-server root=UUID=7d9adc6b-cfec-42fa-b469-bc09ccd24478 ro quiet
   PATH=(custom, user)
  SourcePackage: qemu-kvm
  dmi.bios.date: 11/20/2009
  dmi.bios.vendor: IBM Corp.
  dmi.bios.version: -[Y4E131BUS-1.02]-
  dmi.board.name: 49Y6715
  dmi.board.vendor: IBM
  dmi.board.version: GA
  dmi.chassis.type: 23
  dmi.chassis.vendor: IBM
  dmi.chassis.version: GA
  dmi.modalias: dmi:bvnIBMCorp.:bvr-[Y4E131BUS-1.02]-:bd11/20/2009:svnIBM:pnIBMSystemx3400M2Server-[7836AC1]-:pvr06:rvnIBM:rn49Y6715:rvrGA:cvnIBM:ct23:cvrGA:
  dmi.product.name: IBM System x3400 M2 Server -[7836AC1]-
  dmi.product.version: 06
  dmi.sys.vendor: IBM

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