[PATCH net-next,v2] hv_netvsc: fix vf serial matching with pci slot info

From: Haiyang Zhang <haiyangz@microsoft.com>

The VF device's serial number is saved as a string in PCI slot's
kobj name, not the slot->number. This patch corrects the netvsc
driver, so the VF device can be successfully paired with synthetic
NIC.

Fixes: 00d7ddba1143 ("hv_netvsc: pair VF based on serial number")
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 9bcaf204a7d4..ded623862003 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c

@@ -2030,14 +2030,15 @@ static void netvsc_vf_setup(struct work_struct *w)
 	rtnl_unlock();
 }
 
-/* Find netvsc by VMBus serial number.
- * The PCI hyperv controller records the serial number as the slot.
+/* Find netvsc by VF serial number.
+ * The PCI hyperv controller records the serial number as the slot kobj name.
  */
 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 pci_dev *pdev;
+	u32 serial;
 
 	if (!parent || !dev_is_pci(parent))
 		return NULL; /* not a PCI device */

@@ -2048,16 +2049,22 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
 		return NULL;
 	}
 
+	if (kstrtou32(kobject_name(&pdev->slot->kobj), 10, &serial)) {
+		netdev_notice(vf_netdev, "Invalid vf serial:%s\n",
+			      pdev->slot->kobj.name);
+		return NULL;
+	}
+
 	list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
 		if (!ndev_ctx->vf_alloc)
 			continue;
 
-		if (ndev_ctx->vf_serial == pdev->slot->number)
+		if (ndev_ctx->vf_serial == serial)
 			return hv_get_drvdata(ndev_ctx->device_ctx);
 	}
 
 	netdev_notice(vf_netdev,
-		      "no netdev found for slot %u\n", pdev->slot->number);
+		      "no netdev found for vf serial:%u\n", serial);
 	return NULL;
 }
 

-- 
2.18.0

On Fri, 12 Oct 2018 20:55:15 +0000
Haiyang Zhang [off-list ref] wrote:

Thanks for fixing this.

  

+	if (kstrtou32(kobject_name(&pdev->slot->kobj), 10, &serial)) {
+		netdev_notice(vf_netdev, "Invalid vf serial:%s\n",
+			      pdev->slot->kobj.name);
+		return NULL;
+	}

Shouldn't this use kobject_name() in the message as well.

Looking at the pci.h code there is already an API to get name from
slot (it uses kobject_name()). So please use that one.

-----Original Message-----
From: Stephen Hemminger <stephen@networkplumber.org>
Sent: Friday, October 12, 2018 6:21 PM
To: Haiyang Zhang <redacted>
Cc: Haiyang Zhang <haiyangz@microsoft.com>; davem@davemloft.net;
netdev@vger.kernel.org; olaf@aepfle.de; linux-kernel@vger.kernel.org;
devel@linuxdriverproject.org; vkuznets [off-list ref]
Subject: Re: [PATCH net-next, v2] hv_netvsc: fix vf serial matching with pci slot
info

On Fri, 12 Oct 2018 20:55:15 +0000
Haiyang Zhang [off-list ref] wrote:

Thanks for fixing this.

quoted

+	if (kstrtou32(kobject_name(&pdev->slot->kobj), 10, &serial)) {
+		netdev_notice(vf_netdev, "Invalid vf serial:%s\n",
+			      pdev->slot->kobj.name);
+		return NULL;
+	}

Shouldn't this use kobject_name() in the message as well.

Looking at the pci.h code there is already an API to get name from slot (it uses
kobject_name()). So please use that one.

Sure, I will look for that api. Thanks.