Page 1 of 1

Running CHR as CAPsMAN on KVM - virtio, e1000 bug

Posted: Mon May 20, 2019 10:28 pm
by rb9999
I've noticed that there might be a bug in virtio vNIC support in CHR 6.44.3 (and probably other versions as well). I've been able to replicate the issue as I deployed a test CHR in Centos 7 (QEMU emulator version 2.12.0 (qemu-kvm-ev-2.12.0-18.el7_6.3.1)) with CAPsMAN, and RB951-2n's wlan1 as CAP.

In case of using local-fowarding=yes in datapath everything seems to work okay, but when local-forwarding is disabled, clients complain as uploads don't seem to work at all as seen on the following speedtests

I can mitigate the issue using rtl8139 instead of virtio, but it only supports 100Mbps, and CPU utilization according to tool profile is worse than expected (~40-60% of cpu0/ethernet for one client at about 40Mbps of download), and using e1000 doesn't work for me in production environment as I have 9 ethernets connected to CHR VM, and traffic is only seen on some ethernets but not all.

Can someone using KVM virtualization redo the test with CHR/CAPsMAN deployed with virtio networking?

Re: Running CHR as CAPsMAN on KVM - virtio, e1000 bug

Posted: Mon Jun 24, 2019 1:55 pm
by mkx
virtio networking seems to be (slightly) broken in many linux kernel versions (including the latest 4.9) ... I've had my share of problems running "normal" linux and I've given up - I moved to use e1000-type of virtual NIC in my VMs.