[ovs-dev] [PATCH] datapath-windows: Pause switch state

[Alin Serdean]

Comments inlined.

> -----Mesaj original-----
> De la: Nithin Raju [mailto:nithin at vmware.com]
> Trimis: Monday, February 29, 2016 10:43 PM
> Către: Alin Serdean <aserdean at cloudbasesolutions.com>;
> dev at openvswitch.org
> Subiect: Re: [ovs-dev] [PATCH] datapath-windows: Pause switch state
> 
> Alin,
> Can you pls. add KeMemoryBarrier(); after the ŒdataFlowState¹ was set to
> OvsSwitchPaused?
[Alin Gabriel Serdean: ] Of course
> 
> What does a ŒNetEventFilterPreDetach¹ event mean in the context of a
> Hyper-V switch? Will the OvsExtPause() get invoked after that? If so, we¹ll
> have to update the ASSERT in OvsExtPause() which assumes that we are in
> OvsSwitchRunning.
[Alin Gabriel Serdean: ] Theoretically it should be the case of: https://msdn.microsoft.com/en-us/library/windows/hardware/ff569988%28v=vs.85%29.aspx
NetEventFilterPreDetach gets called before OvsExtPause during boot or in other situations that I could not pinpoint exactly.
The problem is we need to support both situations, this will help solve our handles problems.
> 
> -- Nithin
> 
> -----Original Message-----
> From: dev <dev-bounces at openvswitch.org> on behalf of Alin Serdean
> <aserdean at cloudbasesolutions.com>
> Date: Friday, February 26, 2016 at 6:08 AM
> To: "dev at openvswitch.org" <dev at openvswitch.org>
> Subject: [ovs-dev] [PATCH] datapath-windows: Pause switch state
> 
> >A PnP(plug and play) event will be triggered before trying to disable
> >the extension. We could use this PnP event to prepare for detaching the
> >datapath.
> >
> >This patch sets the switch into a paused state so no more net buffers
> >are queued.
> >
> >Also clean some commentaries.
> >
> >Signed-off-by: Alin Gabriel Serdean <aserdean at cloudbasesolutions.com>
> >---
> > datapath-windows/ovsext/Switch.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> >diff --git a/datapath-windows/ovsext/Switch.c
> >b/datapath-windows/ovsext/Switch.c
> >index 77bafb4..882d587 100644
> >--- a/datapath-windows/ovsext/Switch.c
> >+++ b/datapath-windows/ovsext/Switch.c
> >@@ -352,7 +352,7 @@ OvsExtPause(NDIS_HANDLE filterModuleContext,
> >         NdisMSleep(1000);
> >     }
> >
> >-    OVS_LOG_TRACE("Exit: OvsDetach Successfully");
> >+    OVS_LOG_TRACE("Exit: OvsExtPause Successfully");
> >     return NDIS_STATUS_SUCCESS;
> > }
> >
> >@@ -605,6 +605,10 @@ OvsExtNetPnPEvent(NDIS_HANDLE
> filterModuleContext,
> >         }
> >     }
> >
> >+    if (netPnPEvent->NetPnPEvent.NetEvent == NetEventFilterPreDetach) {
> >+        switchContext->dataFlowState = OvsSwitchPaused;
> >+    }
> >+
> >     status = NdisFNetPnPEvent(switchContext->NdisFilterHandle,
> >                               netPnPEvent);
> >     OVS_LOG_TRACE("Exit: OvsExtNetPnPEvent");
> >--
> >1.9.5.msysgit.0
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