> From: devel [mailto:driverdev-devel-bounces@xxxxxxxxxxxxxxxxxxxxxx] On Behalf > Of Dexuan Cui > Sent: Thursday, July 30, 2015 18:20 > To: David Miller <davem@xxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx> > Cc: olaf@xxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; jasowang@xxxxxxxxxx; > driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > stephen@xxxxxxxxxxxxxxxxxx; stefanha@xxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; > apw@xxxxxxxxxxxxx; pebolle@xxxxxxxxxx; dan.carpenter@xxxxxxxxxx > Subject: RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks to > process hvsock connection > > > From: David Miller > > Sent: Thursday, July 30, 2015 6:27 > > > > From: Dexuan Cui > > Date: Tue, 28 Jul 2015 05:35:11 -0700 > > > > > With the 2 APIs supplied by the VMBus driver, the coming net/hvsock driver > > > can register 2 callbacks and can know when a new hvsock connection is > > > offered by the host, and when a hvsock connection is being closed by the > > > host. > > > > > This is an extremely terrible interface. > > > > It's an opaque hook that allows on registry, and it's solve purpose > > is to allow a backdoor call into a foreign driver in another module. > > > > These are exactly the things we try to avoid. > > Hi David, > Thanks a lot for your reviewing and the suggestion! > > > Why not create a real abstraction where clients register an object, > > that can be contained as a sub-member inside of their own driver > > private, that provides the callback registry mechanism. Hi David, Can you please have a look at my below questions? I like your idea of a real abstraction. Your answer would definitely help me to implement that correctly. > Please pardon me for my inexperience. > Can you please be a bit more specific? > I guess maybe you're referencing a common design pattern in the driver > code, so an example in some existing driver would be the best. :-) > > "clients register an object " -- > does the "clients" mean the hvsock driver? > and the "object" means the 2 callbacks? > > IMHO, here the vmbus driver has to synchronously pass the 2 events > to the hvsock driver, so a "backdoor call into the hvsock driver" is > inevitable anyway? > > e.g., in the path vmbus_process_offer() -> hvsock_process_offer(), the > return value of the latter is important to the former, because on error > the former needs to clean up some internal states of the vmbus driver (that > is, the "goto err_deq_chan"). > > > > That way you can register multiple clients, do things like allow > > AF_PACKET capturing of vmbus traffic, etc. > > I thought AF_PACKET can only capture IP packets or Ethernet frames. > Can it be used to capture AF_UNIX packet? > If yes, I suppose we can consider making it work for AF_HYPERV too, > if people ask for that. > > -- Dexuan Thanks, -- Dexuan _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
