From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Wilson Subject: Re: [PATCH] Add device_model_pvdevice parameter for HVM guests Date: Fri, 12 Jul 2013 15:34:09 -0700 Message-ID: <20130712223405.GA7091@u109add4315675089e695.ant.amazon.com> References: <1372935006-32464-1-git-send-email-paul.durrant@citrix.com> <20130711175800.GB7435@u109add4315675089e695.ant.amazon.com> <9AAE0902D5BC7E449B7C8E4E778ABCD0061DAD@LONPEX01CL01.citrite.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <9AAE0902D5BC7E449B7C8E4E778ABCD0061DAD@LONPEX01CL01.citrite.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: Paul Durrant Cc: Stefano Stabellini , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On Fri, Jul 12, 2013 at 07:57:09AM +0000, Paul Durrant wrote: > > -----Original Message----- > > From: Matt Wilson [mailto:msw@amazon.com] > > Sent: 11 July 2013 18:58 > > To: Paul Durrant > > Cc: xen-devel@lists.xen.org; Stefano Stabellini > > Subject: Re: [Xen-devel] [PATCH] Add device_model_pvdevice parameter > > for HVM guests > > > > On Thu, Jul 04, 2013 at 11:50:06AM +0100, Paul Durrant wrote: > > > The parameter determines which, if any, xen-pvdevice is specified on the > > > QEMU command line. The default value is 'none' which means no > > argument will > > > be passed. A value of 'xenserver' specifies a xen-pvdevice with device-id > > > 0xc000 (the initial value in the xenserver namespace - see > > > docs/misc/pci-device-reservations.txt). > > > > Why bake this into the toolset API? I don't like the idea of a toolset > > API change every time a new device ID is introduced by a PV driver. > > > > Can this be a free form text parameter instead? > > > > From a user perspective having a documented list makes life > easier. If you want to choose arbitrary values (for development > purposes perhaps) then you do still have the option of using the > device_model_args[_hvm] parameter in your xl.cfg to specify whatever > -device argument you want. I just want to make sure that new versions of PV drivers can be used without a toolstack update (so long as they're backwards compatible with the older Xen and driver domain). This seems possible, so from my perspective: Acked-by: Matt Wilson