From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antonios Motakis Subject: Re: [RFC PATCH v3 0/3] vfio: platform: return device properties for a platform device Date: Thu, 27 Aug 2015 15:36:15 +0200 Message-ID: <55DF124F.8020801@huawei.com> References: <1419024032-1269-1-git-send-email-a.motakis@virtualopensystems.com> <55DF07F0.3070405@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <55DF07F0.3070405@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Eric Auger , kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, alex.williamson@redhat.com, Baptiste Reynal Cc: tech@virtualopensystems.com List-Id: iommu@lists.linux-foundation.org Hello Eric, Myself I am not involved with anything VFIO related at the moment, so (alas= ) I don't have any plans to revisit this series. If someone decides to pick it up, of course I can offer my feedback and sup= port. Cheers, Antonios On 27-Aug-15 14:52, Eric Auger wrote: > Hi Baptiste, Antonios, > = > What are the plans wrt this series? I am currently integrating another > QEMU VFIO platform devices where this series could be useful I think > (Feb 2015). Do you intend to follow up and bring it upstream? > = > Alex, do you see some show-stoppers in this series or do you advise to > simply follow-up? > = > Thank you in advance > = > Best Regards > = > Eric > = > = > On 12/19/2014 10:20 PM, Antonios Motakis wrote: >> This RFC's intention is to show what an interface to access device >> properties for the VFIO platform driver can look like. These properties >> can be from the device tree node describing the device, or ACPI properti= es >> in the future. >> >> If a device property corresponding to a platform device bound by VFIO PL= ATFORM >> or VFIO AMBA is available, this patch series will allow the user to query >> for this information. This can be useful for userspace drivers to automa= tically >> query parameters related to the device. >> >> Specifically for QEMU, reading the "compatible" property of the device t= ree >> node could be of use to find out what device is being assigned to the gu= est and >> handle appropriately a wider range of devices in the future, and to gene= rate an >> appropriate device tree for the guest. >> >> Older versions of this series where specifically targeted at device tree >> properties. This version has been reworked on top of Rafael J. Wysocki's >> uniform device properties API for device tree and ACPI devices. This wil= l allow >> us to use the API in the future with devices described via ACPI. >> >> This also means a kernel including the uniform device properties API is = needed >> to apply these patches, in additon to the VFIO patches, e.g. branch pm+a= cpi-3.19-rc1 >> from https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/ >> >> The API to get the list of available properties and the device tree full= _name >> have been removed. These probably don't serve an useful purpose, as the = user >> of this API need to know anyway what properties are specific to the devi= ce he >> wants to access with VFIO. If we decide to reintroduce the list of prope= rties >> in the future, the generic device properties API in the kernel will have= to >> be extended accordingly. >> >> A kernel with this series and all the dependencies applied can be pulled= from >> branch vfio-device-properties-v3 from the repository: >> https://github.com/virtualopensystems/linux-kvm-arm.git >> >> Changes since v2: >> - Reworked on top of Rafael J. Wysocki's uniform device properties API = for >> device tree and ACPI >> - Support for u64 array properties >> - Removed API to get list of available properties and device tree full_= name >> Changes since v1: >> - Updated for VFIO platform patch series v8: >> VFIO AMBA devices now supported in addition to VFIO PLATFORM devices >> - Refactored and cleaned up the code >> >> Antonios Motakis (3): >> vfio: platform: add device properties skeleton and user API >> vfio: platform: access device property as a list of strings >> vfio: platform: return device properties as arrays of unsigned >> integers >> >> drivers/vfio/platform/Makefile | 3 +- >> drivers/vfio/platform/properties.c | 162 +++++++++++++++++++= +++++++ >> drivers/vfio/platform/vfio_platform_common.c | 35 ++++++ >> drivers/vfio/platform/vfio_platform_private.h | 7 ++ >> include/uapi/linux/vfio.h | 26 +++++ >> 5 files changed, 232 insertions(+), 1 deletion(-) >> create mode 100644 drivers/vfio/platform/properties.c >> > = -- = Antonios Motakis Virtualization Engineer Huawei Technologies Duesseldorf GmbH European Research Center Riesstrasse 25, 80992 M=FCnchen