From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ilias Apalodimas Subject: Re: [PATCH v2 03/40] iommu/sva: Manage process address spaces Date: Thu, 24 May 2018 14:50:39 +0300 Message-ID: <20180524115039.GA10260@apalos> References: <20180511190641.23008-1-jean-philippe.brucker@arm.com> <20180511190641.23008-4-jean-philippe.brucker@arm.com> <20180516163117.622693ea@jacob-builder> <20180522094334.71f0e36b@jacob-builder> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Jean-Philippe Brucker Cc: "xieyisheng1@huawei.com" , "kvm@vger.kernel.org" , "linux-pci@vger.kernel.org" , "xuzaibo@huawei.com" , "jonathan.cameron@huawei.com" , Will Deacon , "okaya@codeaurora.org" , "linux-mm@kvack.org" , "yi.l.liu@intel.com" , "ashok.raj@intel.com" , "tn@semihalf.com" , "joro@8bytes.org" , "robdclark@gmail.com" , "bharatku@xilinx.com" , "linux-acpi@vger.kernel.org" , "liudongdong3@huawei.com" , "rfranz@cavium.com" , "devicetree@vger.kernel.org" , "kevin.tian@intel.com" List-Id: devicetree@vger.kernel.org > Interesting, I hadn't thought about this use-case before. At first I > thought you were talking about mdev devices assigned to VMs, but I think > you're referring to mdevs assigned to userspace drivers instead? Out of > curiosity, is it only theoretical or does someone actually need this? There has been some non upstreamed efforts to have mdev and produce userspace drivers. Huawei is using it on what they call "wrapdrive" for crypto devices and we did a proof of concept for ethernet interfaces. At the time we choose not to involve the IOMMU for the reason you mentioned, but having it there would be good. Thanks Ilias