[PATCH 1/6][groovy:linux-azure] hv_netvsc: Make netvsc/VF binding check both MAC and serial number

[Tim Gardner]

From: Dexuan Cui <decui at microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/1928788

Currently the netvsc/VF binding logic only checks the PCI serial number.

The Microsoft Azure Network Adapter (MANA) supports multiple net_device
interfaces (each such interface is called a "vPort", and has its unique
MAC address) which are backed by the same VF PCI device, so the binding
logic should check both the MAC address and the PCI serial number.

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

Co-developed-by: Haiyang Zhang <haiyangz at microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz at microsoft.com>
Co-developed-by: Shachar Raindel <shacharr at microsoft.com>
Signed-off-by: Shachar Raindel <shacharr at microsoft.com>
Acked-by: Stephen Hemminger <stephen at networkplumber.org>
Signed-off-by: Dexuan Cui <decui at microsoft.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit 64ff412ad41fe3a5bf759ff4844dc1382176485c)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 drivers/net/hyperv/netvsc_drv.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 3b0dc1f0ef21..e98bcde0e542 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2237,6 +2237,7 @@ 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;
 
@@ -2259,8 +2260,17 @@ 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,
-- 
2.17.1