Hi, The bug report below does indeed match everything I have experienced. Upon further inspection, 2.6.28.9 is also affected, just less so. Unfortunately I have applied this patch to 2.6.29.1: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2f181855a0 And if anything, it made things worse... (speed was down to just 6KB/s because of the number of broken packets) Any ideas? Cheers Antoine Mark McLoughlin wrote: > On Sun, 2009-04-19 at 14:48 +0300, Avi Kivity wrote: >> Antoine Martin wrote: >>> -----BEGIN PGP SIGNED MESSAGE----- >>> Hash: SHA512 >>> >>> Wireshark was showing a huge amount of invalid packets (wrong checksum) >>> - - that was the cause of the slowdown. >>> Simply rebooting the host into 2.6.28.9 fixed *everything*, regardless >>> of whether the guests use virtio or ne2k_pci/etc. >>> The guests are still running 2.6.29.1, but I am not likely to try that >>> release again on the host anytime soon! Ouch! >>> >> >> Strange, no significant tun changes between .28 and .29. > > Sounds to me like it's this: > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2f181855a0 > > davem said he was queueing up for stable, but it's not in yet: > > http://kerneltrap.org/mailarchive/linux-netdev/2009/3/30/5337934 > > I'll check that it's in the queue. > > Cheers, > Mark. > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html