2018-10-11 20:16:16

by Haiyang Zhang

[permalink] [raw]
Subject: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info

From: Haiyang Zhang <[email protected]>

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")
Signed-off-by: Haiyang Zhang <[email protected]>
---
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..8121ce34a39f 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(pdev->slot->kobj.name, 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



2018-10-11 22:31:41

by Haiyang Zhang

[permalink] [raw]
Subject: RE: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info



> -----Original Message-----
> From: Haiyang Zhang <[email protected]>
> Sent: Thursday, October 11, 2018 4:15 PM
> To: [email protected]; [email protected]
> Cc: Haiyang Zhang <[email protected]>; KY Srinivasan
> <[email protected]>; Stephen Hemminger <[email protected]>;
> [email protected]; vkuznets <[email protected]>;
> [email protected]; [email protected]
> Subject: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info
>
> From: Haiyang Zhang <[email protected]>
>
> 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")
> Signed-off-by: Haiyang Zhang <[email protected]>

Thanks Stephen for the reminder -- I added the "reported-by" here:

Reported-by: Vitaly Kuznetsov <[email protected]>

2018-10-12 06:28:26

by Vitaly Kuznetsov

[permalink] [raw]
Subject: RE: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info

Haiyang Zhang <[email protected]> writes:

>> -----Original Message-----
>> From: Haiyang Zhang <[email protected]>
>> Sent: Thursday, October 11, 2018 4:15 PM
>> To: [email protected]; [email protected]
>> Cc: Haiyang Zhang <[email protected]>; KY Srinivasan
>> <[email protected]>; Stephen Hemminger <[email protected]>;
>> [email protected]; vkuznets <[email protected]>;
>> [email protected]; [email protected]
>> Subject: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info
>>
>> From: Haiyang Zhang <[email protected]>
>>
>> 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")
>> Signed-off-by: Haiyang Zhang <[email protected]>
>
> Thanks Stephen for the reminder -- I added the "reported-by" here:
>
> Reported-by: Vitaly Kuznetsov <[email protected]>

Thanks)

The difference in the hack I sent to Stephen was that instead of using
kstrtou32() and checking the return value I opted for snprintf() and
doing strncmp().

--
Vitaly

2018-10-12 06:36:59

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info

On Thu, Oct 11, 2018 at 08:14:34PM +0000, Haiyang Zhang wrote:
> From: Haiyang Zhang <[email protected]>
>
> 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")
> Signed-off-by: Haiyang Zhang <[email protected]>
> ---
> 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..8121ce34a39f 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(pdev->slot->kobj.name, 10, &serial)) {

kobject_name()?

And that feels _very_ fragile to me. This is now an api that you are
guaranteeing will never change?

Good luck with that!

greg k-h

2018-10-12 17:39:35

by Haiyang Zhang

[permalink] [raw]
Subject: RE: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info



> -----Original Message-----
> From: Greg KH <[email protected]>
> Sent: Friday, October 12, 2018 2:36 AM
> To: Haiyang Zhang <[email protected]>
> Cc: [email protected]; [email protected]; [email protected]; Stephen
> Hemminger <[email protected]>; [email protected];
> [email protected]; vkuznets <[email protected]>
> Subject: Re: [PATCH net-next] hv_netvsc: fix vf serial matching with pci slot info
>
> On Thu, Oct 11, 2018 at 08:14:34PM +0000, Haiyang Zhang wrote:
> > From: Haiyang Zhang <[email protected]>
> >
> > 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")
> > Signed-off-by: Haiyang Zhang <[email protected]>
> > ---
> > 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..8121ce34a39f
> > 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(pdev->slot->kobj.name, 10, &serial)) {
>
> kobject_name()?
>
> And that feels _very_ fragile to me. This is now an api that you are
> guaranteeing will never change?

Thanks for the suggestion -- I will update it to use kobject_name() to
access the name.

For stability, the VF NIC's serial numbers are always unique according
to the Hyper-V documents. Other devices may have same numbers,
but they are not handled by netvsc driver.

Thanks,
- Haiyang