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

[Haiyang Zhang <haiyangz@microsoft.com>]

> -----Original Message-----
> From: Stephen Hemminger <stephen@networkplumber.org>
> Sent: Friday, April 16, 2021 12:40 PM
> To: Dexuan Cui <decui@microsoft.com>
> Cc: davem@davemloft.net; kuba@kernel.org; KY Srinivasan
> <kys@microsoft.com>; Haiyang Zhang <haiyangz@microsoft.com>; Stephen
> Hemminger <sthemmin@microsoft.com>; wei.liu@kernel.org; Wei Liu
> <liuwe@microsoft.com>; netdev@vger.kernel.org; leon@kernel.org;
> andrew@lunn.ch; bernd@petrovitsch.priv.at; rdunlap@infradead.org;
> Shachar Raindel <shacharr@microsoft.com>; linux-kernel@vger.kernel.org;
> linux-hyperv@vger.kernel.org
> Subject: Re: [PATCH v7 net-next] net: mana: Add a driver for Microsoft Azure
> Network Adapter (MANA)
> 
> On Thu, 15 Apr 2021 23:07:05 -0700
> Dexuan Cui <decui@microsoft.com> wrote:
> 
> > diff --git a/drivers/net/hyperv/netvsc_drv.c
> b/drivers/net/hyperv/netvsc_drv.c
> > index 7349a70af083..f682a5572d84 100644
> > --- a/drivers/net/hyperv/netvsc_drv.c
> > +++ b/drivers/net/hyperv/netvsc_drv.c
> > @@ -2297,6 +2297,7 @@ static struct net_device *get_netvsc_byslot(const
> struct net_device *vf_netdev)
> >  {
> >  	struct device *parent = vf_netdev->dev.parent;
> >  	struct net_device_context *ndev_ctx;
> > +	struct net_device *ndev;
> >  	struct pci_dev *pdev;
> >  	u32 serial;
> >
> > @@ -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