From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xu Zaibo Subject: Re: [PATCH v2 13/40] vfio: Add support for Shared Virtual Addressing Date: Tue, 4 Sep 2018 10:12:37 +0800 Message-ID: <5B8DEA15.7020404@huawei.com> References: <20180511190641.23008-1-jean-philippe.brucker@arm.com> <20180511190641.23008-14-jean-philippe.brucker@arm.com> <5B83B11E.7010807@huawei.com> <1d5b6529-4e5a-723c-3f1b-dd5a9adb490c@arm.com> <5B89F818.7060300@huawei.com> <3a961aff-e830-64bb-b6a9-14e08de1abf5@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <3a961aff-e830-64bb-b6a9-14e08de1abf5-5wv7dgnIgG8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Jean-Philippe Brucker , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org" Cc: "xieyisheng1-hv44wF8Li93QT0dZR+AlfA@public.gmane.org" , "liubo95-hv44wF8Li93QT0dZR+AlfA@public.gmane.org" , Will Deacon , "okaya-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org" , "liguozhu-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org" , fanghao11 , "ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "rfranz-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org" , "kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "rgummal-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org" , =?UTF-8?B?57Gz57Gz?= , "dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org" , "ilias.apalodimas-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org" , "alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , Robin Murphy , "christian.koenig-5C7GfCeVMHo@public.gmane.org" List-Id: iommu@lists.linux-foundation.org On 2018/9/3 18:34, Jean-Philippe Brucker wrote: > On 01/09/18 03:23, Xu Zaibo wrote: >> As one application takes a whole function while using VFIO-PCI, why do >> the application and the >> function need to enable PASID capability? (Since just one I/O page table >> is enough for them.) > At the moment the series doesn't provide support for SVA without PASID > (on the I/O page fault path, 08/40). In addition the BIND ioctl could be > used by the owner application to bind other processes (slaves) and > perform sub-assignment. But that feature is incomplete because we don't > send stop_pasid notification to the owner when a slave dies. > So, Could I understand like this? 1. While the series are finished well, VFIO-PCI device can be held by only one process through binding IOCTL command without PASID (without PASID being exposed user space). 2. While using VFIO-PCI device to support multiple processes with SVA series, a primary process with multiple secondary processes must be deployed just like DPDK(https://www.dpdk.org/). And, the PASID still has to be exposed to user land. Thanks, Zaibo .