Re: [PATCH] hyperv: Add netpoll support

2014-07-09 Thread Richard Weinberger 
Am 09.07.2014 01:43, schrieb Francois Romieu:
 Richard Weinberger rich...@nod.at :
 Am 09.07.2014 00:47, schrieb Francois Romieu:
 [...]
 What are you taking about ? netconsole does not need to receive.

 Isn't netconsole is only one user of netpoll ?
 
 Out of tree users are irrelevant. See netpoll related comments in
 cd6362befe4cc7bf589a5236d2a780af2d47bcc9

Thanks lot for pointing this out!

 Of course netconsole needs only to transmit SKBs.
 But if you look at other -ndo_poll_controller implementations
 you'll notice that they care also about receiving.
 
 It's just the long, illuminating history of netpoll :o)
 
 Some limited Rx netpoll support may be done but it needs more work
 than was originally advertised.
 
 hyperv start_xmit handler almost does its own Tx completion as you have
 noticed. The situation is imho close to a virtual device one as was veth
 in bb446c19fefd7b4435adb12a9dd7666adc5b553a.

 Bad commit reference: bb446c19fefd7b4435adb12a9dd7666adc5b553a
 
 Sorry, it currently belongs to davem's net-next.

Found it already. :)

Thanks,
//richard
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

[PATCH] hyperv: Add netpoll support

2014-07-08 Thread Richard Weinberger 
In order to have at least a netconsole to debug kernel issues on
Windows Azure this patch implements netpoll support.
Sending packets is easy, netvsc_start_xmit() does already everything
needed.
To receive we need to trigger the channel callback which is usally
called via tasklet_schedule().

Signed-off-by: Richard Weinberger rich...@nod.at
---
 drivers/net/hyperv/netvsc_drv.c | 14 ++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 4fd71b7..367b71e 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -736,6 +736,17 @@ static int netvsc_set_mac_addr(struct net_device *ndev, 
void *p)
return err;
 }
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void netvsc_poll_controller(struct net_device *net)
+{
+   struct net_device_context *net_device_ctx = netdev_priv(net);
+   struct hv_device *dev = net_device_ctx-device_ctx;
+
+   local_bh_disable();
+   netvsc_channel_cb(dev-channel);
+   local_bh_enable();
+}
+#endif
 
 static const struct ethtool_ops ethtool_ops = {
.get_drvinfo= netvsc_get_drvinfo,
@@ -751,6 +762,9 @@ static const struct net_device_ops device_ops = {
.ndo_validate_addr =eth_validate_addr,
.ndo_set_mac_address =  netvsc_set_mac_addr,
.ndo_select_queue = netvsc_select_queue,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+   .ndo_poll_controller =  netvsc_poll_controller,
+#endif
 };
 
 /*
-- 
2.0.1

___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

RE: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Haiyang Zhang 


 -Original Message-
 From: Richard Weinberger [mailto:rich...@nod.at]
 Sent: Tuesday, July 8, 2014 5:32 AM
 To: KY Srinivasan; Haiyang Zhang
 Cc: de...@linuxdriverproject.org; net...@vger.kernel.org; linux-
 ker...@vger.kernel.org; Richard Weinberger
 Subject: [PATCH] hyperv: Add netpoll support
 
 In order to have at least a netconsole to debug kernel issues on
 Windows Azure this patch implements netpoll support.
 Sending packets is easy, netvsc_start_xmit() does already everything
 needed.
 To receive we need to trigger the channel callback which is usally
 called via tasklet_schedule().
 
 Signed-off-by: Richard Weinberger rich...@nod.at
 ---
  drivers/net/hyperv/netvsc_drv.c | 14 ++
  1 file changed, 14 insertions(+)
 
 diff --git a/drivers/net/hyperv/netvsc_drv.c
 b/drivers/net/hyperv/netvsc_drv.c
 index 4fd71b7..367b71e 100644
 --- a/drivers/net/hyperv/netvsc_drv.c
 +++ b/drivers/net/hyperv/netvsc_drv.c
 @@ -736,6 +736,17 @@ static int netvsc_set_mac_addr(struct net_device
 *ndev, void *p)
   return err;
  }
 
 +#ifdef CONFIG_NET_POLL_CONTROLLER
 +static void netvsc_poll_controller(struct net_device *net)
 +{
 + struct net_device_context *net_device_ctx = netdev_priv(net);
 + struct hv_device *dev = net_device_ctx-device_ctx;
 +
 + local_bh_disable();
 + netvsc_channel_cb(dev-channel);

This can only poll the primary channel not the sub channels.

Thanks,
- Haiyang
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

RE: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread KY Srinivasan 


 -Original Message-
 From: Richard Weinberger [mailto:rich...@nod.at]
 Sent: Tuesday, July 8, 2014 2:32 AM
 To: KY Srinivasan; Haiyang Zhang
 Cc: de...@linuxdriverproject.org; net...@vger.kernel.org; linux-
 ker...@vger.kernel.org; Richard Weinberger
 Subject: [PATCH] hyperv: Add netpoll support
 
 In order to have at least a netconsole to debug kernel issues on Windows
 Azure this patch implements netpoll support.
 Sending packets is easy, netvsc_start_xmit() does already everything
 needed.
 To receive we need to trigger the channel callback which is usally called via
 tasklet_schedule().
 
 Signed-off-by: Richard Weinberger rich...@nod.at
 ---
  drivers/net/hyperv/netvsc_drv.c | 14 ++
  1 file changed, 14 insertions(+)
 
 diff --git a/drivers/net/hyperv/netvsc_drv.c
 b/drivers/net/hyperv/netvsc_drv.c index 4fd71b7..367b71e 100644
 --- a/drivers/net/hyperv/netvsc_drv.c
 +++ b/drivers/net/hyperv/netvsc_drv.c
 @@ -736,6 +736,17 @@ static int netvsc_set_mac_addr(struct net_device
 *ndev, void *p)
   return err;
  }
 
 +#ifdef CONFIG_NET_POLL_CONTROLLER
 +static void netvsc_poll_controller(struct net_device *net) {
 + struct net_device_context *net_device_ctx = netdev_priv(net);
 + struct hv_device *dev = net_device_ctx-device_ctx;
 +
 + local_bh_disable();
 + netvsc_channel_cb(dev-channel);
 + local_bh_enable();
 +}
 +#endif

Each channel is bound to a specific VCPU in the guest and the channel callback 
is expected to be delivered on
the VCPU the channel is bound to. This code is not satisfying that requirement.

Regards,

K. Y

___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Richard Weinberger 
Am 08.07.2014 20:01, schrieb KY Srinivasan:
 
 
 -Original Message-
 From: Richard Weinberger [mailto:rich...@nod.at]
 Sent: Tuesday, July 8, 2014 2:32 AM
 To: KY Srinivasan; Haiyang Zhang
 Cc: de...@linuxdriverproject.org; net...@vger.kernel.org; linux-
 ker...@vger.kernel.org; Richard Weinberger
 Subject: [PATCH] hyperv: Add netpoll support

 In order to have at least a netconsole to debug kernel issues on Windows
 Azure this patch implements netpoll support.
 Sending packets is easy, netvsc_start_xmit() does already everything
 needed.
 To receive we need to trigger the channel callback which is usally called via
 tasklet_schedule().

 Signed-off-by: Richard Weinberger rich...@nod.at
 ---
  drivers/net/hyperv/netvsc_drv.c | 14 ++
  1 file changed, 14 insertions(+)

 diff --git a/drivers/net/hyperv/netvsc_drv.c
 b/drivers/net/hyperv/netvsc_drv.c index 4fd71b7..367b71e 100644
 --- a/drivers/net/hyperv/netvsc_drv.c
 +++ b/drivers/net/hyperv/netvsc_drv.c
 @@ -736,6 +736,17 @@ static int netvsc_set_mac_addr(struct net_device
 *ndev, void *p)
  return err;
  }

 +#ifdef CONFIG_NET_POLL_CONTROLLER
 +static void netvsc_poll_controller(struct net_device *net) {
 +struct net_device_context *net_device_ctx = netdev_priv(net);
 +struct hv_device *dev = net_device_ctx-device_ctx;
 +
 +local_bh_disable();
 +netvsc_channel_cb(dev-channel);
 +local_bh_enable();
 +}
 +#endif
 
 Each channel is bound to a specific VCPU in the guest and the channel 
 callback is expected to be delivered on
 the VCPU the channel is bound to. This code is not satisfying that 
 requirement.

But struct hv_device has only one channel attribute. How does this work with 
multiple VCPUs?

Anyways, what solution to you propose?

Thanks,
//richard
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Richard Weinberger 
Am 08.07.2014 19:55, schrieb Haiyang Zhang:
 
 
 -Original Message-
 From: Richard Weinberger [mailto:rich...@nod.at]
 Sent: Tuesday, July 8, 2014 5:32 AM
 To: KY Srinivasan; Haiyang Zhang
 Cc: de...@linuxdriverproject.org; net...@vger.kernel.org; linux-
 ker...@vger.kernel.org; Richard Weinberger
 Subject: [PATCH] hyperv: Add netpoll support

 In order to have at least a netconsole to debug kernel issues on
 Windows Azure this patch implements netpoll support.
 Sending packets is easy, netvsc_start_xmit() does already everything
 needed.
 To receive we need to trigger the channel callback which is usally
 called via tasklet_schedule().

 Signed-off-by: Richard Weinberger rich...@nod.at
 ---
  drivers/net/hyperv/netvsc_drv.c | 14 ++
  1 file changed, 14 insertions(+)

 diff --git a/drivers/net/hyperv/netvsc_drv.c
 b/drivers/net/hyperv/netvsc_drv.c
 index 4fd71b7..367b71e 100644
 --- a/drivers/net/hyperv/netvsc_drv.c
 +++ b/drivers/net/hyperv/netvsc_drv.c
 @@ -736,6 +736,17 @@ static int netvsc_set_mac_addr(struct net_device
 *ndev, void *p)
  return err;
  }

 +#ifdef CONFIG_NET_POLL_CONTROLLER
 +static void netvsc_poll_controller(struct net_device *net)
 +{
 +struct net_device_context *net_device_ctx = netdev_priv(net);
 +struct hv_device *dev = net_device_ctx-device_ctx;
 +
 +local_bh_disable();
 +netvsc_channel_cb(dev-channel);
 
 This can only poll the primary channel not the sub channels.

Sub channels in terms of one channel per VCPU as KY said?

*confused*,
//richard
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

RE: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Haiyang Zhang 


 -Original Message-
 From: Richard Weinberger [mailto:rich...@nod.at]
 Sent: Tuesday, July 8, 2014 2:40 PM
 To: Haiyang Zhang; KY Srinivasan
 Cc: de...@linuxdriverproject.org; net...@vger.kernel.org; linux-
 ker...@vger.kernel.org
 Subject: Re: [PATCH] hyperv: Add netpoll support
 
 Am 08.07.2014 19:55, schrieb Haiyang Zhang:
 
 
  -Original Message-
  From: Richard Weinberger [mailto:rich...@nod.at]
  Sent: Tuesday, July 8, 2014 5:32 AM
  To: KY Srinivasan; Haiyang Zhang
  Cc: de...@linuxdriverproject.org; net...@vger.kernel.org; linux-
  ker...@vger.kernel.org; Richard Weinberger
  Subject: [PATCH] hyperv: Add netpoll support
 
  In order to have at least a netconsole to debug kernel issues on
  Windows Azure this patch implements netpoll support.
  Sending packets is easy, netvsc_start_xmit() does already everything
  needed.
  To receive we need to trigger the channel callback which is usally
  called via tasklet_schedule().
 
  Signed-off-by: Richard Weinberger rich...@nod.at
  ---
   drivers/net/hyperv/netvsc_drv.c | 14 ++
   1 file changed, 14 insertions(+)
 
  diff --git a/drivers/net/hyperv/netvsc_drv.c
  b/drivers/net/hyperv/netvsc_drv.c
  index 4fd71b7..367b71e 100644
  --- a/drivers/net/hyperv/netvsc_drv.c
  +++ b/drivers/net/hyperv/netvsc_drv.c
  @@ -736,6 +736,17 @@ static int netvsc_set_mac_addr(struct net_device
  *ndev, void *p)
 return err;
   }
 
  +#ifdef CONFIG_NET_POLL_CONTROLLER
  +static void netvsc_poll_controller(struct net_device *net)
  +{
  +  struct net_device_context *net_device_ctx = netdev_priv(net);
  +  struct hv_device *dev = net_device_ctx-device_ctx;
  +
  +  local_bh_disable();
  +  netvsc_channel_cb(dev-channel);
 
  This can only poll the primary channel not the sub channels.
 
 Sub channels in terms of one channel per VCPU as KY said?
 
 *confused*,

Since it's used only for debugging, polling the subchannels may not be
necessary.

Regarding the CPU binding, KY will reply you in another email.

Thanks,
- Haiyang

___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Richard Weinberger 
Am 08.07.2014 22:03, schrieb KY Srinivasan:
 The VCPU the channel is bound to is available in the channel state. You could 
 use the following code
 Fragment to ensure that the call is made on the right cpu:
 
 smp_call_function_single(dev-channel-target_cpu,
  netvsc_channel_cb, dev-channel, 
 true);

This won't work as netpoll runs with IRQs disabled.
-ndo_poll_controller() has to make sure that SKBs can be received and 
transmitted
while IRQs are off. I thought calling the channel callback by hand would be 
enough
to receive SKBs.

Thanks,
//richard
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Richard Weinberger 
Am 09.07.2014 00:47, schrieb Francois Romieu:
 Richard Weinberger rich...@nod.at :
 [...]
 This won't work as netpoll runs with IRQs disabled.
 -ndo_poll_controller() has to make sure that SKBs can be received and 
 transmitted
 while IRQs are off. I thought calling the channel callback by hand would be
 enough to receive SKBs.
 
 What are you taking about ? netconsole does not need to receive.

Isn't netconsole is only one user of netpoll?
Of course netconsole needs only to transmit SKBs.
But if you look at other -ndo_poll_controller implementations
you'll notice that they care also about receiving.

 hyperv start_xmit handler almost does its own Tx completion as you have
 noticed. The situation is imho close to a virtual device one as was veth
 in bb446c19fefd7b4435adb12a9dd7666adc5b553a.

Bad commit reference: bb446c19fefd7b4435adb12a9dd7666adc5b553a

:-(

Thanks,
//richard
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Francois Romieu 
Richard Weinberger rich...@nod.at :
[...]
 This won't work as netpoll runs with IRQs disabled.
 -ndo_poll_controller() has to make sure that SKBs can be received and 
 transmitted
 while IRQs are off. I thought calling the channel callback by hand would be
 enough to receive SKBs.

What are you taking about ? netconsole does not need to receive.

hyperv start_xmit handler almost does its own Tx completion as you have
noticed. The situation is imho close to a virtual device one as was veth
in bb446c19fefd7b4435adb12a9dd7666adc5b553a.

-- 
Ueimor
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Richard Weinberger 
Am 09.07.2014 00:47, schrieb Francois Romieu:
 Richard Weinberger rich...@nod.at :
 [...]
 This won't work as netpoll runs with IRQs disabled.
 -ndo_poll_controller() has to make sure that SKBs can be received and 
 transmitted
 while IRQs are off. I thought calling the channel callback by hand would be
 enough to receive SKBs.
 
 What are you taking about ? netconsole does not need to receive.
 
 hyperv start_xmit handler almost does its own Tx completion as you have
 noticed. The situation is imho close to a virtual device one as was veth
 in bb446c19fefd7b4435adb12a9dd7666adc5b553a.

Ah, net-next.git.
My first (in-house) patch had the same empty poll controller as tun.c and now 
veth.c have.
If we are fine with tx only, I'll happily resend an updated patch with an empty 
poll controller. :-)

Thanks,
//richard
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] hyperv: Add netpoll support

2014-07-08 Thread Francois Romieu 
Richard Weinberger rich...@nod.at :
 Am 09.07.2014 00:47, schrieb Francois Romieu:
[...]
  What are you taking about ? netconsole does not need to receive.
 
 Isn't netconsole is only one user of netpoll ?

Out of tree users are irrelevant. See netpoll related comments in
cd6362befe4cc7bf589a5236d2a780af2d47bcc9

 Of course netconsole needs only to transmit SKBs.
 But if you look at other -ndo_poll_controller implementations
 you'll notice that they care also about receiving.

It's just the long, illuminating history of netpoll :o)

Some limited Rx netpoll support may be done but it needs more work
than was originally advertised.

  hyperv start_xmit handler almost does its own Tx completion as you have
  noticed. The situation is imho close to a virtual device one as was veth
  in bb446c19fefd7b4435adb12a9dd7666adc5b553a.
 
 Bad commit reference: bb446c19fefd7b4435adb12a9dd7666adc5b553a

Sorry, it currently belongs to davem's net-next.

-- 
Ueimor
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel