Jiri Pirko
2018-Apr-09 08:07 UTC
[RFC PATCH net-next v5 3/4] virtio_net: Extend virtio to use VF datapath when available
Sat, Apr 07, 2018 at 12:59:14AM CEST, sridhar.samudrala at intel.com wrote:>On 4/6/2018 5:48 AM, Jiri Pirko wrote: >> Thu, Apr 05, 2018 at 11:08:22PM CEST, sridhar.samudrala at intel.com wrote:[...]>> > +static int virtnet_bypass_join_child(struct net_device *bypass_netdev, >> > + struct net_device *child_netdev) >> > +{ >> > + struct virtnet_bypass_info *vbi; >> > + bool backup; >> > + >> > + vbi = netdev_priv(bypass_netdev); >> > + backup = (child_netdev->dev.parent == bypass_netdev->dev.parent); >> > + if (backup ? rtnl_dereference(vbi->backup_netdev) : >> > + rtnl_dereference(vbi->active_netdev)) { >> > + netdev_info(bypass_netdev, >> > + "%s attempting to join bypass dev when %s already present\n", >> > + child_netdev->name, backup ? "backup" : "active"); >> Bypass module should check if there is already some other netdev >> enslaved and refuse right there. > >This will work for virtio-net with 3 netdev model, but this check has to be done by netvsc >as its bypass_netdev is same as the backup_netdev. >Will add a flag while registering with the bypass module to indicate if the driver is doing >a 2 netdev or 3 netdev model and based on that flag this check can be done in bypass module >for 3 netdev scenario.Just let me undestand it clearly. What I expect the difference would be between 2netdev and3 netdev model is this: 2netdev: bypass_master / / VF_slave 3netdev: bypass_master / \ / \ VF_slave backup_slave Is that correct? If not, how does it look like? Thanks!
Samudrala, Sridhar
2018-Apr-09 18:47 UTC
[RFC PATCH net-next v5 3/4] virtio_net: Extend virtio to use VF datapath when available
On 4/9/2018 1:07 AM, Jiri Pirko wrote:> Sat, Apr 07, 2018 at 12:59:14AM CEST, sridhar.samudrala at intel.com wrote: >> On 4/6/2018 5:48 AM, Jiri Pirko wrote: >>> Thu, Apr 05, 2018 at 11:08:22PM CEST, sridhar.samudrala at intel.com wrote: > [...] > >>>> +static int virtnet_bypass_join_child(struct net_device *bypass_netdev, >>>> + struct net_device *child_netdev) >>>> +{ >>>> + struct virtnet_bypass_info *vbi; >>>> + bool backup; >>>> + >>>> + vbi = netdev_priv(bypass_netdev); >>>> + backup = (child_netdev->dev.parent == bypass_netdev->dev.parent); >>>> + if (backup ? rtnl_dereference(vbi->backup_netdev) : >>>> + rtnl_dereference(vbi->active_netdev)) { >>>> + netdev_info(bypass_netdev, >>>> + "%s attempting to join bypass dev when %s already present\n", >>>> + child_netdev->name, backup ? "backup" : "active"); >>> Bypass module should check if there is already some other netdev >>> enslaved and refuse right there. >> This will work for virtio-net with 3 netdev model, but this check has to be done by netvsc >> as its bypass_netdev is same as the backup_netdev. >> Will add a flag while registering with the bypass module to indicate if the driver is doing >> a 2 netdev or 3 netdev model and based on that flag this check can be done in bypass module >> for 3 netdev scenario. > Just let me undestand it clearly. What I expect the difference would be > between 2netdev and3 netdev model is this: > 2netdev: > bypass_master > / > / > VF_slave > > 3netdev: > bypass_master > / \ > / \ > VF_slave backup_slave > > Is that correct? If not, how does it look like? > >Looks correct. VF_slave and backup_slave are the original netdevs and are present in both the models. In the 3 netdev model, bypass_master netdev is created and VF_slave and backup_slave are marked as the 2 slaves of this new netdev. In the 2 netdev model, backup_slave acts as bypass_master and the bypass module doesn't have access to netdev_priv of the backup_slave. Once i moved all the ndo_ops of the master netdev to bypass module, i realized that we can move the create/destroy of the upper netdev also to bypass.c. That way the changes to virtio_net become very minimal. With these updates, bypass module now supports both the models by exporting 2 sets of functions. 3 netdev: int bypass_master_create(struct net_device *backup_netdev, struct bypass_master **pbypass_master); void bypass_master_destroy(struct bypass_master *bypass_master); 2 netdev: int bypass_master_register(struct net_device *backup_netdev, struct bypass_ops *ops, struct bypass_master **pbypass_master); void bypass_master_unregister(struct bypass_master *bypass_master); Will send the next revision in a day or two. Thanks Sridhar
Jiri Pirko
2018-Apr-10 10:55 UTC
[RFC PATCH net-next v5 3/4] virtio_net: Extend virtio to use VF datapath when available
Mon, Apr 09, 2018 at 08:47:06PM CEST, sridhar.samudrala at intel.com wrote:>On 4/9/2018 1:07 AM, Jiri Pirko wrote: >> Sat, Apr 07, 2018 at 12:59:14AM CEST, sridhar.samudrala at intel.com wrote: >> > On 4/6/2018 5:48 AM, Jiri Pirko wrote: >> > > Thu, Apr 05, 2018 at 11:08:22PM CEST, sridhar.samudrala at intel.com wrote: >> [...] >> >> > > > +static int virtnet_bypass_join_child(struct net_device *bypass_netdev, >> > > > + struct net_device *child_netdev) >> > > > +{ >> > > > + struct virtnet_bypass_info *vbi; >> > > > + bool backup; >> > > > + >> > > > + vbi = netdev_priv(bypass_netdev); >> > > > + backup = (child_netdev->dev.parent == bypass_netdev->dev.parent); >> > > > + if (backup ? rtnl_dereference(vbi->backup_netdev) : >> > > > + rtnl_dereference(vbi->active_netdev)) { >> > > > + netdev_info(bypass_netdev, >> > > > + "%s attempting to join bypass dev when %s already present\n", >> > > > + child_netdev->name, backup ? "backup" : "active"); >> > > Bypass module should check if there is already some other netdev >> > > enslaved and refuse right there. >> > This will work for virtio-net with 3 netdev model, but this check has to be done by netvsc >> > as its bypass_netdev is same as the backup_netdev. >> > Will add a flag while registering with the bypass module to indicate if the driver is doing >> > a 2 netdev or 3 netdev model and based on that flag this check can be done in bypass module >> > for 3 netdev scenario. >> Just let me undestand it clearly. What I expect the difference would be >> between 2netdev and3 netdev model is this: >> 2netdev: >> bypass_master >> / >> / >> VF_slave >> >> 3netdev: >> bypass_master >> / \ >> / \ >> VF_slave backup_slave >> >> Is that correct? If not, how does it look like? >> >> >Looks correct. >VF_slave and backup_slave are the original netdevs and are present in both the models. >In the 3 netdev model, bypass_master netdev is created and VF_slave and backup_slave are >marked as the 2 slaves of this new netdev.You say it looks correct and in another sentence you provide completely different description. Could you please look again? [...]
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