From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [virtio-dev] Re: net_failover slave udev renaming (was Re: [RFC PATCH net-next v6 4/4] netvsc: refactor notifier/event handling code to use the bypass framework) Date: Wed, 27 Feb 2019 23:47:33 -0500 Message-ID: <20190227233812-mutt-send-email-mst__15862.5762489223$1551329748$gmane$org@kernel.org> References: <20190225210529-mutt-send-email-mst@kernel.org> <20190227173710-mutt-send-email-mst@kernel.org> <20190227184601-mutt-send-email-mst@kernel.org> <20190227193923-mutt-send-email-mst@kernel.org> <20190227165205.307ed83c@cakuba.netronome.com> <20190227201857-mutt-send-email-mst@kernel.org> <20190227175218.736e13b6@cakuba.netronome.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20190227175218.736e13b6@cakuba.netronome.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Jakub Kicinski Cc: Alexander Duyck , virtio-dev , Jiri Pirko , "Samudrala, Sridhar" , virtualization@lists.linux-foundation.org, Siwei Liu , liran.alon@oracle.com, Netdev , si-wei liu , David Miller List-Id: virtualization@lists.linuxfoundation.org On Wed, Feb 27, 2019 at 05:52:18PM -0800, Jakub Kicinski wrote: > On Wed, 27 Feb 2019 20:26:02 -0500, Michael S. Tsirkin wrote: > > On Wed, Feb 27, 2019 at 04:52:05PM -0800, Jakub Kicinski wrote: > > > On Wed, 27 Feb 2019 19:41:32 -0500, Michael S. Tsirkin wrote: > > > > > As this scheme adds much complexity to the kernel naming convention > > > > > (currently it's just ethX names) that no userspace can understand. > > > > > > > > Anything that pokes at slaves needs to be specially designed anyway. > > > > Naming seems like a minor issue. > > > > > > Can the users who care about the naming put net_failover into > > > "user space will do the bond enslavement" mode, and do the bond > > > creation/management themselves from user space (in systemd/ > > > Network Manager) based on the failover flag? > > > > Putting issues of compatibility aside (userspace tends to be confused if > > you give it two devices with same MAC), how would you have it work in > > practice? Timer based hacks like netvsc where if userspace didn't > > respond within X seconds we assume it won't and do everything ourselves? > > Well, what I'm saying is basically if user space knows how to deal with > the auto-bonding, we can put aside net_failover for the most part. It > can either be blacklisted or it can have some knob which will > effectively disable the auto-enslavement. OK I guess we could add a module parameter to skip this. Is this what you mean? > Auto-bonding capable user space can do the renames, spawn the bond, > etc. all by itself. I'm basically going back to my initial proposal > here :) There is a RedHat bugzilla for the NetworkManager team to do > this, but we merged net_failover before those folks got around to > implementing it. In particular because there's no policy involved whatsoever here so it's just mechanism being pushed up to userspace. > IOW if NM/systemd is capable of doing the auto-bonding itself it can > disable the kernel mechanism and take care of it all. If kernel is > booted with an old user space which doesn't have capable NM/systemd - > net_failover will kick in and do its best. Sure - it's just 2 lines of code, see below. Signed-off-by: Michael S. Tsirkin But I don't intend to bother until there's actual interest from userspace developers to bother. In particular it is not just NM/systemd even on Fedora - e.g. you will need to teach dracut to somehow detect and handle this - right now it gets confused if there are two devices with same MAC addresses. diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 955b3e76eb8d..dd2b2c370003 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -43,6 +43,7 @@ static bool csum = true, gso = true, napi_tx; module_param(csum, bool, 0444); module_param(gso, bool, 0444); module_param(napi_tx, bool, 0644); +module_param(disable_failover, bool, 0644); /* FIXME: MTU in config. */ #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) @@ -3163,6 +3164,7 @@ static int virtnet_probe(struct virtio_device *vdev) virtnet_init_settings(dev); - if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) { + if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY) && + !disable_failover) { vi->failover = net_failover_create(vi->dev); if (IS_ERR(vi->failover)) { err = PTR_ERR(vi->failover);