From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [RFC PATCH v5 0/3] vfio: platform: return device properties for a platform device Date: Mon, 5 Oct 2015 11:53:25 +0200 Message-ID: <20151005095325.GG9011@cbox> References: <1443604077-3155-1-git-send-email-b.reynal@virtualopensystems.com> <1443814099.26107.124.camel@redhat.com> <20151002202844.GD32011@cbox> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 462EB41291 for ; Mon, 5 Oct 2015 05:51:27 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id P9RsvZjmckRf for ; Mon, 5 Oct 2015 05:51:26 -0400 (EDT) Received: from mail-la0-f49.google.com (mail-la0-f49.google.com [209.85.215.49]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 2D4A54117C for ; Mon, 5 Oct 2015 05:51:26 -0400 (EDT) Received: by laddr2 with SMTP id dr2so4508045lad.3 for ; Mon, 05 Oct 2015 02:53:16 -0700 (PDT) Content-Disposition: inline In-Reply-To: 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: Baptiste Reynal Cc: Alex Williamson , "tech@virtualopensystems.com" , Linux IOMMU , "kvmarm@lists.cs.columbia.edu" List-Id: kvmarm@lists.cs.columbia.edu [why are you top-posting?] On Mon, Oct 05, 2015 at 11:42:38AM +0200, Baptiste Reynal wrote: > In this patch series we want to wrap an already available kernel > interface to expose a device property to userspace, which 'already available kernel interface' is that exactly? > in order to keep > the code lighter on the userspace. We need those properties in VFIO as I'm not sure I agree with your 'need those properties in VFIO' statement here, can you elaborate? > VFIO grants the possibility to develop userspace drivers. > > The sysfs doesn't seems to be ready for this kind of usage. We can > only find raw data that require heavy parsing. Here we retrieve > directly usable data and it can be extended later according to new > needs (as it is already done with ACPI). Why couldn't you expose this kind of data through sysfs instead of VFIO and independently of VFIO? Would that be more wrong/difficult/whatever? > > This interface has been developed for VFIO and is currently bound to > it, though there is no special dependencies with it. We could make it > more generic, but I can only think of VFIO to use it. Thanks, -Christoffer