Re: [PATCH 0/2] Handle xen_platform_pci=0 case

[George Dunlap <george.dunlap@eu.citrix.com>]

On 22/11/13 17:18, Anthony PERARD wrote:
> On Fri, Nov 22, 2013 at 03:56:13PM +0000, Ian Campbell wrote:
>> On Fri, 2013-11-22 at 15:13 +0000, Anthony PERARD wrote:
>>> There are two patches, the first one adds an option to specifies the QEMU
>>> machine that a user wants and we handle the xen_platform_pci=0 case using the
>>> new option.
>> I'm thinking we should make this new option an enum of actually
>> supported machine types, rather than just a free reign. Makes more sense
>> from a "what do we support" PoV.
> And start with the following list ?
> pc
> pc-i440fx-1.7
> pc-i440fx-1.6
> pc-i440fx-1.5
> pc-i440fx-1.4
> pc-1.3
> pc-1.2
> pc-1.1
> pc-1.0
> pc-0.15
> pc-0.14
> pc-0.13
> pc-0.12
> pc-0.11
> pc-0.10
> xenfv
>
> I wonder how many of this will work. I suspect most of them. The only
> down side is that it will be necessary to patch libxl if one want to
> try, let say q35.

In a way I think that's the point -- by allowing the user to specify an 
arbitrary sting, we are implicitly supporting a gigantic range of things 
which may work in one release or in one particular configuration and 
then break in a different one.  By making an enum, we bake in the exact 
ones which we consider to be valid.

Also, we've been trying to get away from exposing a bunch of qemu-isms 
to the user via libxl and the xl config file.  What might the *user* be 
trying to do in specifying this option?  We should make sure the 
interface specifies things the user actually wants, and then use qemu's 
options to implement that, rather than asking the user to specify qemu 
stuff directly.

  -George