RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks to process hvsock connection
> -Original Message- > From: Dexuan Cui > Sent: Friday, August 7, 2015 3:27 AM > To: KY Srinivasan ; David Miller > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > step...@networkplumber.org; stefa...@redhat.com; > net...@vger.kernel.org; a...@canonical.com; pebo...@tiscali.nl; > dan.carpen...@oracle.com > Subject: RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks > to process hvsock connection > > > -Original Message- > > From: KY Srinivasan > > Sent: Friday, August 7, 2015 2:28 > > To: Dexuan Cui ; David Miller > > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > > step...@networkplumber.org; stefa...@redhat.com; > net...@vger.kernel.org; > > a...@canonical.com; pebo...@tiscali.nl; dan.carpen...@oracle.com > > Subject: RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register > callbacks to > > process hvsock connection > > > > > -Original Message- > > > From: Dexuan Cui > > > Sent: Wednesday, August 5, 2015 9:54 PM > > > To: David Miller ; KY Srinivasan > > > > > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; > jasow...@redhat.com; > > > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > > > step...@networkplumber.org; stefa...@redhat.com; > > > net...@vger.kernel.org; a...@canonical.com; pebo...@tiscali.nl; > > > dan.carpen...@oracle.com > > > Subject: RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register > callbacks > > > to process hvsock connection > > > > > > > From: devel [mailto:driverdev-devel-boun...@linuxdriverproject.org] > On > > > Behalf > > > > Of Dexuan Cui > > > > Sent: Thursday, July 30, 2015 18:20 > > > > To: David Miller ; KY Srinivasan > > > > > > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; > jasow...@redhat.com; > > > > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > > > > step...@networkplumber.org; stefa...@redhat.com; > > > net...@vger.kernel.org; > > > > a...@canonical.com; pebo...@tiscali.nl; dan.carpen...@oracle.com > > > > 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
RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks to process hvsock connection
> -Original Message- > From: KY Srinivasan > Sent: Friday, August 7, 2015 2:28 > To: Dexuan Cui ; David Miller > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > step...@networkplumber.org; stefa...@redhat.com; net...@vger.kernel.org; > a...@canonical.com; pebo...@tiscali.nl; dan.carpen...@oracle.com > Subject: RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register > callbacks to > process hvsock connection > > > -Original Message- > > From: Dexuan Cui > > Sent: Wednesday, August 5, 2015 9:54 PM > > To: David Miller ; KY Srinivasan > > > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > > step...@networkplumber.org; stefa...@redhat.com; > > net...@vger.kernel.org; a...@canonical.com; pebo...@tiscali.nl; > > dan.carpen...@oracle.com > > Subject: RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register > > callbacks > > to process hvsock connection > > > > > From: devel [mailto:driverdev-devel-boun...@linuxdriverproject.org] On > > Behalf > > > Of Dexuan Cui > > > Sent: Thursday, July 30, 2015 18:20 > > > To: David Miller ; KY Srinivasan > > > > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > > > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > > > step...@networkplumber.org; stefa...@redhat.com; > > net...@vger.kernel.org; > > > a...@canonical.com; pebo...@tiscali.nl; dan.carpen...@oracle.com > > > 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 packetsor 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,
RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks to process hvsock connection
> -Original Message- > From: Dexuan Cui > Sent: Wednesday, August 5, 2015 9:54 PM > To: David Miller ; KY Srinivasan > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > step...@networkplumber.org; stefa...@redhat.com; > net...@vger.kernel.org; a...@canonical.com; pebo...@tiscali.nl; > dan.carpen...@oracle.com > Subject: RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks > to process hvsock connection > > > From: devel [mailto:driverdev-devel-boun...@linuxdriverproject.org] On > Behalf > > Of Dexuan Cui > > Sent: Thursday, July 30, 2015 18:20 > > To: David Miller ; KY Srinivasan > > > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > > step...@networkplumber.org; stefa...@redhat.com; > net...@vger.kernel.org; > > a...@canonical.com; pebo...@tiscali.nl; dan.carpen...@oracle.com > > 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 packetsor 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, The notion of a channel on Hyper-V has been mapped to a device on Linux and the mechanism we have had of notifying the driver of the creation of the channel was through registering this device with the kernel (vmbus_device_create). The first exception to this was when we introduced multi-channel support that broke the assumption of this one to one mapping between the channel and Linux device. In the case of the sub-channels, we handled the driver notification issue via the sub-channel callback that the driver registers at the point of opening the channel. Perhaps we could make the sub-channel handling mechanism more generic to handle the case of VMSOCK as well? Regards, K. Y > > -- Dexuan > > Thanks, > -- Dexuan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks to process hvsock connection
> From: devel [mailto:driverdev-devel-boun...@linuxdriverproject.org] On Behalf > Of Dexuan Cui > Sent: Thursday, July 30, 2015 18:20 > To: David Miller ; KY Srinivasan > Cc: o...@aepfle.de; gre...@linuxfoundation.org; jasow...@redhat.com; > driverdev-de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; > step...@networkplumber.org; stefa...@redhat.com; net...@vger.kernel.org; > a...@canonical.com; pebo...@tiscali.nl; dan.carpen...@oracle.com > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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. 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. Thanks, -- Dexuan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH V4 4/7] Drivers: hv: vmbus: add APIs to register callbacks to process hvsock connection
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. > > Signed-off-by: Dexuan Cui 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. 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. That way you can register multiple clients, do things like allow AF_PACKET capturing of vmbus traffic, etc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
