From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabio Fantoni Subject: Re: Xen 4.3 development update Date: Tue, 14 May 2013 11:39:31 +0200 Message-ID: <51920653.1060309@m2r.biz> References: <518CD8D8.3090307@citrix.com> <518D046A.2090002@m2r.biz> <1368440802.537.45.camel@zakaz.uk.xensource.com> <5190FE81.3060106@m2r.biz> <519101E5.2060309@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <519101E5.2060309@eu.citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: George Dunlap Cc: Anthony Perard , "xen-devel@lists.xen.org" , Ian Campbell , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org Il 13/05/2013 17:08, George Dunlap ha scritto: > On 13/05/13 15:53, Fabio Fantoni wrote: >> Il 13/05/2013 12:26, Ian Campbell ha scritto: >>> On Fri, 2013-05-10 at 15:30 +0100, Fabio Fantoni wrote: >>>> Il 10/05/2013 13:24, Anthony PERARD ha scritto: >>>>> On 10/05/13 12:08, Anthony PERARD wrote: >>>>>> On Fri, May 10, 2013 at 12:00 PM, George Dunlap >>>>>> wrote: >>>>>>> On Fri, May 10, 2013 at 11:26 AM, George Dunlap >>>>>>> wrote: >>>>>>>> * qxl not actually working >>>>>>>> > qxl apparently not enabled during compile by default >>>>>>>> > Appear to be some other bugs even when it is working: >>>>>>>> >http://lists.xen.org/archives/html/xen-devel/2012-11/msg00713.html >>>>>>>> >>>>>>>> owner: ? (Anthony was going to take a look) >>>>>>>> We need to either fix both of these problems or disable qxl >>>>>>>> for 4.3 >>>>>>> Anthony, you were going to take a look at this; did you make any >>>>>>> progress? >>>>>> Yes, I'm still trying to figure out how to enable qxl in the VM. >>>>> And now, I can search why QEMU crash when starting Xorg with qxl. >>>>> >>>>> >>>> Hi, thanks for your help. >>>> I'm trying to have qxl full working on xen since end of 2011. >>>> Since half of 2012 is at least working as standard vga. >>> This means with: >>> vga = "qxl" >>> >>> in your configuration file? >> Yes >>> Are you saying that this configuration >>> works? >> For now it works only as standard vga >>> If not this then which configuration do you believe works? >> With qxl driver enabled on domU's os, qemu crashes >>>> The libxl patch should be correct, also with memory size setting. >>>> I have tried same parameters of libxl qxl patch without xen and are >>>> working. >>>> Also without kvm was working even if performance was really bad but at >>>> least qemu did not crash on start with qxl driver. >>>> Based on this test the problem seems to be xen related problem, >>>> probably >>>> about hvmloader. >>> What is the configuration which fails? >> See on attachment >>> >>> Which libxl patch "should be correct"? libxl has lots of patches! >> This patch that I refer: >> http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=aab4d1b266ce9891a684704f6abf6a5f6b3f7c24 >> >>> >>> So are you saying that although the libxl patch "should be correct" it >>> is in fact not sufficient to make qxl work? >> The qemu parameters used are correct, for now on xen works only as >> standard vga but on kvm and qemu-only tests works also with qxl driver. >> The difference with xen appares to be only on hvmloader. >> I tried to find the exactly problem without result, based on seabios >> debug I saw that when it detects xen hypervisor, seabios relies on >> tables passed by hvmloader instead generate them. >> Is the only effective difference viewed with seabios debug with and >> without xen. > > OK -- so you're saying that qxl actually *does* work, but just in a > limited fashion: as long as the guest only access the standard vga > interface, then you can connect over spice; but if the guest uses the > special qxl interface, then it crashes. > Yes > We don't really use qxl, so that wasn't clear at first; we thought > that you were saying it didn't work at all. > > If it didn't work at all, then there's no point exposing functionality > that can't actually work. But since there is new functionality > (albeit limited) exposed by the "qxl" option, we should keep it in. > > But we do need to make sure to set people's expectations properly -- > our release notes will have to advertize "partial qxl support". I think it is good point to maintain it and advice that is experimental/partial so can be tested/debugged by users. Without that libxl qxl patch users can't test it with simple device_model_args on xl configuration file but they must change libxl code for disable other emulated vga (and also setting proper videoram size). > > -George