[Pkg-xen-devel] Bug#799122: xen-hypervisor-4.4-amd64: Networking of domUs stops working after a few minutes

[Arne Klein]

Package: xen-hypervisor-4.4-amd64
Version: 4.4.1-9+deb8u1
Severity: important

A few minutes after starting a domU, network access is no longer possible from and to it.

This does not always happen and is not easily reproducible, but seems to occur in all newly started domUs from some point in time on. However, also restarting the dom0 does not necessarily prevent the problem.

At the moment when the network in the domU completely stops working, there is the error message
[2178752.854380] vif vif-33-0 vif33.0: Guest Rx stalled
visible in dmesg in the dom0.

It is sometimes possible to for example ping the domU for a longer time than pinging any host from the domU. Also pings may still be possible for a few minutes, while SSH sessions do no longer work.

We tested the current lenny kernel linux-image-3.16.0-4-amd64 as well as the backport linux-image-4.1.0-0.bpo.1-amd64 on the dom0 as well as the domU. The problem happens with newly created domUs via 'xen-create-image', as well as with older domUs which have been migrated from a debian wheezy dom0. It happens with the vif-route as well as the vif-bridge script in the domU configuration.

When the network stops working, the ARP tables are no longer filled on dom0 and domU, for example:

Address                  HWtype  HWaddress           Flags Mask            Iface
x.y.z.v                     (incomplete)                              vif33.0


-- System Information:
Debian Release: 8.2
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.1.0-0.bpo.1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

xen-hypervisor-4.4-amd64 depends on no packages.

Versions of packages xen-hypervisor-4.4-amd64 recommends:
ii  xen-utils-4.4  4.4.1-9+deb8u1

xen-hypervisor-4.4-amd64 suggests no packages.

-- no debconf information