Date: Tue, 27 Feb 2018 09:17:18 +0100 From: Harry Schmalzbauer <freebsd@omnilan.de> To: Paul Vixie <paul@redbarn.org> Cc: Ruben <mail@osfux.nl>, FreeBSD virtualization <freebsd-virtualization@freebsd.org> Subject: Re: superfluous host interfaces Message-ID: <5A95140E.8030909@omnilan.de> In-Reply-To: <5A94F730.7040009@redbarn.org> References: <20180225131401.GA3138@v007.zyxst.net> <5A93CEB6.1080406@omnilan.de> <a0ccbf77-ec23-127c-0529-ddb05dc689e3@osfux.nl> <5A93D9D0.4090804@omnilan.de> <54f9019e-6e86-8e10-32d7-9f14d159bb0a@osfux.nl> <5A93F9DE.9090908@omnilan.de> <5A94F730.7040009@redbarn.org>
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Bezüglich Paul Vixie's Nachricht vom 27.02.2018 07:14 (localtime): > > > Harry Schmalzbauer wrote: >> Bezüglich Ruben's Nachricht vom 26.02.2018 11:34 (localtime): >>> On 26/02/2018 10:56, Harry Schmalzbauer wrote: >> … >>>> Another, personally very significant, reason is that you'll get a >>>> superfluous host interface for each if_bridge(4), which makes the >>>> output >>>> of plain ifconfig(8) kind of unreadable. >> … >>> By superflous host interfaces, do you mean the tap interfaces configured >>> for each vm together with the bridge interfaces they are "bundled" in? >> >> Additionally to the if_tap(4) ethernet host interfaces, you also get >> if_bridge(4) ethernet interfaces, named bridgeX if I remember correctly. > > you do not remember correctly. Please see next para. >> [mm1.redbarn:amd64] egrep 'bridge|tap' /etc/rc.conf >> autobridge_interfaces="bridge0" >> autobridge_bridge0="tap* igb1" >> cloned_interfaces="bridge0 tap0 tap1 tap2 tap3 tap4 tap5 tap6 tap7" >> ifconfig_bridge0="inet 24.104.150.210/27" >> ifconfig_bridge0_ipv6="inet6 2001:559:8000:cd::2/64 auto_linklocal up" >> ifconfig_tap0="up" >> ifconfig_tap1="up" >> ifconfig_tap2="up" >> ifconfig_tap3="up" >> ifconfig_tap4="up" >> ifconfig_tap5="up" >> ifconfig_tap6="up" >> ifconfig_tap7="up" >> [mm1.redbarn:amd64] ifconfig | egrep '^(bridge|tap)' >> bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 >> mtu 1500 That's what I mean; and it's named bridgeX, so memeory works in that case ;-) If you have only one "LAN" sharing all VMs, the one additional interface is neglectable. But my setups are different. I have almost as many different 802.11q separated ethernet collsion domains (VLANs) as VMs. That's what ESXi's portgroup is used for. I need a separate switch for each VLAN (guests mustn't be able to sniff traffic etc.). … >> And using ng_bridge(4) instead of if_bridge(4) doesn't change the need >> for if_tap(4). Only with vale(4) switches, bhyve(8) was able to provide >> virtio-net connection wihtout "spamming" the host's ethernet interface >> list (no tapX, no bridgeX). > > how did you get bhyve to use the netmap API rather than the tap > character special device? Not me, peter commited the following: https://svnweb.freebsd.org/base/head/usr.sbin/bhyve/pci_virtio_net.c?r1=288470&r2=293459 >From that an, you don't need to add any host ethernet devices/interfaces, simply start your VM with e.g. "-s 1:0,virtio-net,vale0:1,mac=02:03:04:05:06:07". As long as you created vale0, port [:]1 will be created dynamically and also destroyed after shutdown. Again, to mimic ESXi's portgroups, you need one vale(4) switch for each VLAN. And to uplink, you need to utilize if_valn(4), which forces netmap emulated mode. If you don't have/need VLANs, you can uplink a supported NIC via native netmap support, and additionally gain significatn efficiency improvements. Unfortunately, at least if_vlan(4) uplinks, don't work reliably. After some short time, the complete network netmap(4) subsystem locks up. I talked with Vincenco Maffione (a member of Liugi Rizzo's netmap(4) team of University of Pisa) and fixing emulated netpmap mode on FreeBSD doesn't have really high priority there, since such a setup is considered as weak design. For sure, it's a hack/workarround, but we don't have VLAN/portgroup support in vale(4) nor in byhve(8), and writing my own userland filter is beyond my scope. -harry
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