From mboxrd@z Thu Jan 1 00:00:00 1970 From: "G.R." Subject: Re: [PATCH 3/3] qemu-xen-trad: IGD passthrough: Expose vendor specific pci cap on host bridge. Date: Tue, 6 Aug 2013 11:44:52 +0800 Message-ID: References: <51C9A44E.1050309@citrix.com> <20130625145438.GA28904@phenom.dumpdata.com> <51C9B0B9.4000409@citrix.com> <20130626125301.GB4222@phenom.dumpdata.com> <20130701130637.GA10934@phenom.dumpdata.com> <20130715160633.GF2924@reaktio.net> <51E435BF.6010708@citrix.com> <20130715225520.GH2924@reaktio.net> <20130805161503.GN2924@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20130805161503.GN2924@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: =?ISO-8859-1?Q?Pasi_K=E4rkk=E4inen?= Cc: Ian Campbell , Ross Philipson , Stefano Stabellini , Jan Beulich , xen-devel , Jean Guyader List-Id: xen-devel@lists.xenproject.org On Tue, Aug 6, 2013 at 12:15 AM, Pasi K=E4rkk=E4inen wrote: > On Tue, Jul 16, 2013 at 01:55:20AM +0300, Pasi K=E4rkk=E4inen wrote: >> > >>How was that diagnosed? Perhaps that information can be part of the = source >> > >>code to help in the future with diagnosiing which caps are needed and >> > >>which ones can be blacklisted? >> > >> >> > > >> > >I guess that's a question mostly for Ross/Jean as they're the origina= l authors of the patch? >> > >> > We discovered the issue with Windows guests running the vendor >> > drivers for the passed in IGD graphics device. Under certain >> > circumstances (resuming from S3/S4 IIRC), the guest would BSOD. I >> > finally tracked it down to a bad state in the resuming driver >> > because it was not coded to handle the vendor capabilities not being >> > present on the host bridge. BTW, those capabilities are flags >> > indicating what features the IGD card has - their exact meaning is >> > of course proprietary. >> > >> > I cannot say it was only a problem on Windows but rather that that >> > is the only place we ever saw it. >> > >> > I never saw any other capabilities on the hosts bridges at that >> > time, just vendor ones so the patch just handled that. If there were >> > other capabilities, I would think it would have to be determined on >> > a case by case basis whether they were included. Inclusion of each >> > new type would have different ramifications it seems. >> > >> >> Thanks for the explanation. I guess parts of that should go to the patch= description aswell.. >> > > Now patch 2/3 has been applied to qemu-traditional, so only this patch 3/= 3 is missing from qemu-traditional from this series. > > Any other changes outstanding? or only to add some of Ross's comments to = the patch description (and/or sources) ? > I'll have to rework this patch -- Jan believe the code is not very clean with regard to offset / size handling. I proposed an alternative to shadow the registers into the PCI config space of the emulated host controller. There seems no objection on this proposal. I'll do it when I got some spare time. > Thanks, > > -- Pasi >