From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51840) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1RiL-0007eR-Hu for qemu-devel@nongnu.org; Sun, 29 Jun 2014 22:53:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X1RiF-0002WB-Bf for qemu-devel@nongnu.org; Sun, 29 Jun 2014 22:53:05 -0400 Received: from mga09.intel.com ([134.134.136.24]:19483) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X1RiF-0002V5-61 for qemu-devel@nongnu.org; Sun, 29 Jun 2014 22:52:59 -0400 Message-ID: <53B0D106.6040401@intel.com> Date: Mon, 30 Jun 2014 10:52:54 +0800 From: "Chen, Tiejun" MIME-Version: 1.0 References: <1403662641-28526-1-git-send-email-tiejun.chen@intel.com> <1403662641-28526-5-git-send-email-tiejun.chen@intel.com> <53AA6B2D.2030804@redhat.com> <53AD2C8E.8030009@intel.com> <53AD54FD.4010807@redhat.com> <53AFC69A.801@intel.com> <20140629121417.GC26161@redhat.com> In-Reply-To: <20140629121417.GC26161@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [v5][PATCH 4/5] xen, gfx passthrough: create host bridge to passthrough List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , anthony.perard@citrix.com Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, Kelly.Zytaruk@amd.com, qemu-devel@nongnu.org, anthony@codemonkey.ws, yang.z.zhang@intel.com, Paolo Bonzini On 2014/6/29 20:14, Michael S. Tsirkin wrote: > On Sun, Jun 29, 2014 at 03:56:10PM +0800, Chen, Tiejun wrote: >> On 2014/6/27 19:26, Paolo Bonzini wrote: >>> Il 27/06/2014 10:34, Chen, Tiejun ha scritto: >>>> >>>> >>>> So how to separate this to specific to xen? Or you mean we need to >>>> create an new machine to address this scenario? But actually this is >>>> same as xenfv_machine except for these little codes. >>> >>> Yes, please create a new machine so that "-M pc" doesn't have any of >>> these hacks. >> >> But regardless of the machine is 'xenfv' or 'pc', we always call >> pc_init_pci(), then inside, i440fx_init() is always performed. So I think >> even we create a new machine, shouldn't we still call pc_init_pci()? >> >>> >>> Note that "-M xenfv" is obsolete, Xen can now use "-M pc" (i.e. the >>> default). >>> >> >> Yes, Xen can use 'pc'. >> >> Thanks >> Tiejun > > You are creating a new machine type where the pci host > looks like MCH but a bunch of other things are from i440fx. Anthony, Any comments to address this in xen case? Thanks Tiejun > > I have some doubts about this combination being worth supporting - it > does not seem useful for anything except xen from the code you posted, > but maybe you can whittle down the number of places where you poke at > the host to make it reasonable: I can imagine that, if you are lucky and > the registers that i915 wants to poke to make it work on real hardware > happen to fall on top of reserved registers in the i440FX/PIIX3 pci > bridge. OTOH it would be much more likely if you just start with > something that does have MCH, like Q35, or emulate a newer > machine type. This is the path that people who wanted > to boot iOS on QEMU took, and the result is pretty good. > > But regardless, this is clearly not a i440fx nor a q35 pc > so it needs a separate name. > From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Tiejun" Subject: Re: [v5][PATCH 4/5] xen, gfx passthrough: create host bridge to passthrough Date: Mon, 30 Jun 2014 10:52:54 +0800 Message-ID: <53B0D106.6040401@intel.com> References: <1403662641-28526-1-git-send-email-tiejun.chen@intel.com> <1403662641-28526-5-git-send-email-tiejun.chen@intel.com> <53AA6B2D.2030804@redhat.com> <53AD2C8E.8030009@intel.com> <53AD54FD.4010807@redhat.com> <53AFC69A.801@intel.com> <20140629121417.GC26161@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140629121417.GC26161@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: "Michael S. Tsirkin" , anthony.perard@citrix.com Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, Kelly.Zytaruk@amd.com, qemu-devel@nongnu.org, anthony@codemonkey.ws, yang.z.zhang@intel.com, Paolo Bonzini List-Id: xen-devel@lists.xenproject.org On 2014/6/29 20:14, Michael S. Tsirkin wrote: > On Sun, Jun 29, 2014 at 03:56:10PM +0800, Chen, Tiejun wrote: >> On 2014/6/27 19:26, Paolo Bonzini wrote: >>> Il 27/06/2014 10:34, Chen, Tiejun ha scritto: >>>> >>>> >>>> So how to separate this to specific to xen? Or you mean we need to >>>> create an new machine to address this scenario? But actually this is >>>> same as xenfv_machine except for these little codes. >>> >>> Yes, please create a new machine so that "-M pc" doesn't have any of >>> these hacks. >> >> But regardless of the machine is 'xenfv' or 'pc', we always call >> pc_init_pci(), then inside, i440fx_init() is always performed. So I think >> even we create a new machine, shouldn't we still call pc_init_pci()? >> >>> >>> Note that "-M xenfv" is obsolete, Xen can now use "-M pc" (i.e. the >>> default). >>> >> >> Yes, Xen can use 'pc'. >> >> Thanks >> Tiejun > > You are creating a new machine type where the pci host > looks like MCH but a bunch of other things are from i440fx. Anthony, Any comments to address this in xen case? Thanks Tiejun > > I have some doubts about this combination being worth supporting - it > does not seem useful for anything except xen from the code you posted, > but maybe you can whittle down the number of places where you poke at > the host to make it reasonable: I can imagine that, if you are lucky and > the registers that i915 wants to poke to make it work on real hardware > happen to fall on top of reserved registers in the i440FX/PIIX3 pci > bridge. OTOH it would be much more likely if you just start with > something that does have MCH, like Q35, or emulate a newer > machine type. This is the path that people who wanted > to boot iOS on QEMU took, and the result is pretty good. > > But regardless, this is clearly not a i440fx nor a q35 pc > so it needs a separate name. >