From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH] vhost: introduce vDPA based backend Date: Wed, 5 Feb 2020 08:56:48 -0400 Message-ID: <20200205125648.GV23346@mellanox.com> References: <20200131033651.103534-1-tiwei.bie@intel.com> <7aab2892-bb19-a06a-a6d3-9c28bc4c3400@redhat.com> <20200205020247.GA368700@___> <112858a4-1a01-f4d7-e41a-1afaaa1cad45@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <112858a4-1a01-f4d7-e41a-1afaaa1cad45@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Jason Wang Cc: Shahaf Shuler , Tiwei Bie , "mst@redhat.com" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "netdev@vger.kernel.org" , "rob.miller@broadcom.com" , "haotian.wang@sifive.com" , "eperezma@redhat.com" , "lulu@redhat.com" , Parav Pandit , "rdunlap@infradead.org" , "hch@infradead.org" , Jiri Pirko , "hanand@xilinx.com" , mhabets@solarflare List-Id: virtualization@lists.linuxfoundation.org On Wed, Feb 05, 2020 at 03:50:14PM +0800, Jason Wang wrote: > > Would it be better for the map/umnap logic to happen inside each device ? > > Devices that needs the IOMMU will call iommu APIs from inside the driver callback. > > Technically, this can work. But if it can be done by vhost-vpda it will make > the vDPA driver more compact and easier to be implemented. Generally speaking, in the kernel, it is normal to not hoist code of out drivers into subsystems until 2-3 drivers are duplicating that code. It helps ensure the right design is used Jason