[PATCH v8 net-next 1/2] hv_netvsc: Make netvsc/VF binding check both MAC and serial number

From: Dexuan Cui <decui@microsoft.com>
To: davem@davemloft.net, kuba@kernel.org, kys@microsoft.com,
	haiyangz@microsoft.com, stephen@networkplumber.org,
	sthemmin@microsoft.com, wei.liu@kernel.org, liuwe@microsoft.com,
	netdev@vger.kernel.org, leon@kernel.org, andrew@lunn.ch,
	bernd@petrovitsch.priv.at, rdunlap@infradead.org,
	shacharr@microsoft.com
Cc: linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
	Dexuan Cui <decui@microsoft.com>
Subject: [PATCH v8 net-next 1/2] hv_netvsc: Make netvsc/VF binding check both MAC and serial number
Date: Fri, 16 Apr 2021 13:11:58 -0700	[thread overview]
Message-ID: <20210416201159.25807-2-decui@microsoft.com> (raw)
In-Reply-To: <20210416201159.25807-1-decui@microsoft.com>

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

The upcoming 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@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Co-developed-by: Shachar Raindel <shacharr@microsoft.com>
Signed-off-by: Shachar Raindel <shacharr@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.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 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,
-- 
2.25.1

