RE: [PATCH v7 net-next] net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)

[Dexuan Cui]

> From: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Sent: Friday, April 16, 2021 10:11 AM
> > From: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
> > > ...
> > > @@ -2319,8 +2320,17 @@ static struct net_device
> > *get_netvsc_byslot(const struct net_device *vf_netdev)
> > >  		if (!ndev_ctx->vf_alloc)
> > >  			continue;
> > >
> > > -		if (ndev_ctx->vf_serial == serial)
> > > -			return hv_get_drvdata(ndev_ctx->device_ctx);
> > > +		if (ndev_ctx->vf_serial != serial)
> > > +			continue;
> > > +
> > > +		ndev = hv_get_drvdata(ndev_ctx->device_ctx);
> > > +		if (ndev->addr_len != vf_netdev->addr_len ||
> > > +		    memcmp(ndev->perm_addr, vf_netdev->perm_addr,
> > > +			   ndev->addr_len) != 0)
> > > +			continue;
> > > +
> > > +		return ndev;
> > > +
> > >  	}
> > >
> > >  	netdev_notice(vf_netdev,
> >
> >
> > This probably should be a separate patch.
> > I think it is trying to address the case of VF discovery in Hyper-V/Azure where
> > the reported
> > VF from Hypervisor is bogus or confused.
> 
> This is for the Multi vPorts feature of MANA driver, which allows one VF to
> create multiple vPorts (NICs). They have the same PCI device and same VF
> serial number, but different MACs.
> 
> So we put the change in one patch to avoid distro vendors missing this
> change when backporting the MANA driver.
> 
> Thanks,
> - Haiyang

The netvsc change should come together in the same patch with this VF
driver, otherwise the multi-vPorts functionality doesn't work properly.

The netvsc change should not break any other existing VF drivers, because
Hyper-V NIC SR-IOV implementation requires the the NetVSC network
interface and the VF network interface should have the same MAC address,
otherwise things won't work.

Thanks,
Dexuan