From: Haiyang Zhang <haiyangz@microsoft.com>
Sent: Friday, April 16, 2021 10:11 AM

quoted

From: Stephen Hemminger <stephen@networkplumber.org>

quoted

...

@@ -2319,8 +2320,17 @@ static struct net_device

*get_netvsc_byslot(const struct net_device *vf_netdev)

quoted

 		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