From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: [PATCH 1/2 V3] PCI: introduce device assignment interface and refactory related code Date: Sun, 20 Jul 2014 19:58:36 -0600 Message-ID: <1405907916.4463.2.camel@ul30vt.home> References: <1405081802-419-1-git-send-email-ethan.zhao@oracle.com> <1405084407.4098.59.camel@ul30vt.home> <1405088147.4098.64.camel@ul30vt.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" , linux-pci , "e1000-devel@lists.sourceforge.net" , "vaughan.cao@oracle.com" , "jesse.brandeburg@intel.com" , "ethan.kernel@gmail.com" , Ethan Zhao , "linux.nics@intel.com" , "konrad.wilk@oracle.com" , "gleb@kernel.org" , "bhelgaas@google.com" , "boris.ostrovsky@oracle.com" , netdev , "bruce.w.allan@intel.com" , linux-kernel , "john.ronciak@intel.com" , "david.vrabel@citrix.com" , "pbonzini@redhat.com" To: Yuval Mintz Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On Sun, 2014-07-20 at 14:48 +0000, Yuval Mintz wrote: > > On Fri, 2014-07-11 at 07:13 -0600, Alex Williamson wrote: > > > On Fri, 2014-07-11 at 20:30 +0800, Ethan Zhao wrote: > > > > This patch introduces two new device assignment functions > > > > > > > > pci_iov_assign_device(), > > > > pci_iov_deassign_device() > > > > > > > > along with the existed one > > > > > > > > pci_vfs_assigned() > > > > > > > > They construct the VFs assignment management interface, used to > > > > assign/ deassign device to VM and query the VFs reference counter. > > > > instead of direct manipulation of device flag. > > Sorry for the late intrusion into the conversation, and perhaps it's a bit > unrelated, but given that you're creating a 'VF assignment management' > perhaps it's the right place to add some sort of mechanism in order to > prevent module removal once one of its VFs is assigned. > [e.g., incrementing module reference count] > > At the moment [to the best of my knowledge] there's no mechanism > preventing the 'not-so-bright' user from removing the driver, and no good > will come out of it. On what module would the reference count be increased, the PF? The entire "VF assigned" interface is a hack to work around poor architectures like legacy KVM device assignment where there's no proper device owner for the VF. This is "fixed" by using VFIO instead and hopefully deprecating legacy KVM assignment. Thanks, Alex ------------------------------------------------------------------------------ Want fast and easy access to all the code in your enterprise? Index and search up to 200,000 lines of code with a free copy of Black Duck Code Sight - the same software that powers the world's largest code search on Ohloh, the Black Duck Open Hub! Try it now. http://p.sf.net/sfu/bds _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired