Hello. Sorry if duplicate, but I don't found any. When running FreebBSD as guest on xen with options XENHVM device xenpci in kernel the packet forwarding becomes really slow, something near 5kb/s I also tried to disable lro txcsum rxcsum tso with ifconfig but there was no effect. Something like this was in maillist but without happy end. https://lists.freebsd.org/pipermail/freebsd-xen/2014-April/002106.html Linux version on host system with this bug is 3.18.12-gentoo xen-4.5 Please specify if you need more information.
Probably duplicate of https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=188261
and/or: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=197344
(In reply to Sydney Meyer from comment #1) Thank You for fast response. I already tried to run ifconfix xn0 -txcsum -tso4 -lro with no effect. FreeBSD guest used for openvpn with nat on pf(but seems pf has no effect there because I've also tried tried natd) Clients machines for openvpn are with windows/linux/freebsd and there no difference. On all of them there performance drops with xn interface. One more detail FreeBSD guest running in HVM mode. (In reply to Sydney Meyer from comment #2) This I will test tomorrow when will be at work.
(In reply to Sydney Meyer from comment #2) I've checked and behavior looks very similar to https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=197344 After disabling tx perfomance increased but when target server is far away from FreeBSD box then degradation is the same. For example if I will try to fetch something that is near to DC where guest system is than all is fine and speed is great but if I will try to access thru vpn something that is in Asia(for example) the speed is really low. Maybe tcp window somehow cutted and as a result I have low speed on big distances. P.S. Sorry for my English)