Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754404AbbKXOMi (ORCPT ); Tue, 24 Nov 2015 09:12:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38699 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753114AbbKXOMg (ORCPT ); Tue, 24 Nov 2015 09:12:36 -0500 Message-ID: <1448374351.27648.128.camel@redhat.com> Subject: Re: [Intel-gfx] [Announcement] 2015-Q3 release of XenGT - a Mediated Graphics Passthrough Solution from Intel From: Gerd Hoffmann To: Daniel Vetter Cc: Alex Williamson , "igvt-g@ml01.01.org" , "Li, Susie" , "White, Michael L" , "Dong, Eddie" , "intel-gfx@lists.freedesktop.org" , "Reddy, Raghuveer" , "Cowperthwaite, David J" , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xen.org" , qemu-devel , "Zhou, Chao" , Paolo Bonzini , "Zhu, Libo" , "Wang, Hongbo" Date: Tue, 24 Nov 2015 15:12:31 +0100 In-Reply-To: <20151124133135.GY17050@phenom.ffwll.local> References: <547FCAAD.2060406@intel.com> <54AF967B.3060503@intel.com> <5527CEC4.9080700@intel.com> <559B3E38.1080707@intel.com> <562F4311.9@intel.com> <1447870341.4697.92.camel@redhat.com> <1447963356.4697.184.camel@redhat.com> <20151124111917.GO17050@phenom.ffwll.local> <1448368735.27648.110.camel@redhat.com> <20151124133135.GY17050@phenom.ffwll.local> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1603 Lines: 37 Hi, > But there's some work to add generic mmap support to dma-bufs, and for > really simple case (where we don't have a gl driver to handle the dma-buf > specially) for untiled framebuffers that would be all we need? Not requiring gl is certainly a bonus, people might want build qemu without opengl support to reduce the attach surface and/or package dependency chain. And, yes, requirements for the non-gl rendering path are pretty low. qemu needs something it can mmap, and which it can ask pixman to handle. Preferred format is PIXMAN_x8r8g8b8 (qemu uses that internally in alot of places so this avoids conversions). Current plan is to have a special vfio region (not visible to the guest) where the framebuffer lives, with one or two pages at the end for meta data (format and size). Status field is there too and will be used by qemu to request updates and the kernel to signal update completion. Guess I should write that down as vfio rfc patch ... I don't think it makes sense to have fields to notify qemu about which framebuffer regions have been updated, I'd expect with full-screen composing we have these days this information isn't available anyway. Maybe a flag telling whenever there have been updates or not, so qemu can skip update processing in case we have the screensaver showing a black screen all day long. cheers, Gerd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/