Fri, Apr 27, 2018 at 07:06:59PM CEST, [email protected] wrote:
>This patch enables virtio_net to switch over to a VF datapath when a VF
>netdev is present with the same MAC address. It allows live migration
>of a VM with a direct attached VF without the need to setup a bond/team
>between a VF and virtio net device in the guest.
>
>The hypervisor needs to enable only one datapath at any time so that
>packets don't get looped back to the VM over the other datapath. When a VF
>is plugged, the virtio datapath link state can be marked as down. The
>hypervisor needs to unplug the VF device from the guest on the source host
>and reset the MAC filter of the VF to initiate failover of datapath to
>virtio before starting the migration. After the migration is completed,
>the destination hypervisor sets the MAC filter on the VF and plugs it back
>to the guest to switch over to VF datapath.
>
>It uses the generic failover framework that provides 2 functions to create
>and destroy a master failover netdev. When STANDBY feature is enabled, an
>additional netdev(failover netdev) is created that acts as a master device
>and tracks the state of the 2 lower netdevs. The original virtio_net netdev
>is marked as 'standby' netdev and a passthru device with the same MAC is
>registered as 'primary' netdev.
>
>This patch is based on the discussion initiated by Jesse on this thread.
>https://marc.info/?l=linux-virtualization&m=151189725224231&w=2
>
When I enabled the standby feature (hardcoded), I have 2 netdevices now:
4: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
group default qlen 1000
link/ether 52:54:00:b2:a7:f1 brd ff:ff:ff:ff:ff:ff
inet6 fe80::5054:ff:feb2:a7f1/64 scope link
valid_lft forever preferred_lft forever
5: ens3n_sby: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state
UP group default qlen 1000
link/ether 52:54:00:b2:a7:f1 brd ff:ff:ff:ff:ff:ff
inet6 fe80::5054:ff:feb2:a7f1/64 scope link
valid_lft forever preferred_lft forever
However, it seems to confuse my initscripts on Fedora:
[root@test1 ~]# ifup ens3
./network-functions: line 78: [: /etc/dhcp/dhclient-ens3: binary operator
expected
./network-functions: line 80: [: /etc/dhclient-ens3: binary operator expected
./network-functions: line 69: [: /var/lib/dhclient/dhclient-ens3: binary
operator expected
Determining IP information for ens3
ens3n_sby...Cannot find device "ens3n_sby.pid"
Cannot find device "ens3n_sby.lease"
failed.
I tried to change the standby device mac:
ip link set ens3n_sby addr 52:54:00:b2:a7:f2
[root@test1 ~]# ifup ens3
Determining IP information for ens3... done.
[root@test1 ~]#
But now the network does not work. I think that the mac change on
standby device should be probably refused, no?
When I change the mac back, all works fine.
Now I try to change mac of the failover master:
[root@test1 ~]# ip link set ens3 addr 52:54:00:b2:a7:f3
RTNETLINK answers: Operation not supported
That I did expect to work. I would expect this would change the mac of
the master and both standby and primary slaves.
Now I tried to add a primary pci device. I don't have any fancy VF on my
test setup, but I expected the good old 8139cp to work:
[root@test1 ~]# ethtool -i ens9
driver: 8139cp
....
[root@test1 ~]# ip link set ens9 addr 52:54:00:b2:a7:f1
I see no message in dmesg, so I guess the failover module did not
enslave this netdev. The mac change is not monitored. I would expect
that it is and whenever a device changes mac to the failover one, it
should be enslaved and whenever it changes mac back to something else,
it should be released - the primary one ofcourse.
[...]
>+static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
>+ size_t len)
>+{
>+ struct virtnet_info *vi = netdev_priv(dev);
>+ int ret;
>+
>+ if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
>+ return -EOPNOTSUPP;
>+
>+ ret = snprintf(buf, len, "_sby");
please avoid the "_".
[...]
