[Bug 616064] [NEW] Broken networking in kvm guests

[Brian Fallik]

Public bug reported:

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
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 2.6.32.15+drm33.5
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)
KvmCmdLine:
 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 127.0.0.1:0 -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
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
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

** Affects: qemu-kvm (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug lucid

-- 
Broken networking in kvm guests
https://bugs.launchpad.net/bugs/616064
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