Re: [Qemu-devel] [v2][PATCH] libxl: add one machine property to support IGD GFX passthrough

[Chen, Tiejun]

On 2015/2/2 20:54, Ian Jackson wrote:
> Wei Liu writes ("Re: [v2][PATCH] libxl: add one machine property to support IGD GFX 
> passthrough"):
> > On Mon, Feb 02, 2015 at 09:17:23AM +0800, Tiejun Chen wrote:
> > > When we're working to support IGD GFX passthrough with qemu
> > > upstream, instead of "-gfx_passthru" we'd like to make that
> > > a machine option, "-machine xxx,-igd-passthru=on". This need
> > > to bring a change on tool side.
> ...
> > My suggestion has one premise -- if upstream QEMU has already released
> > that -gfx_passthru option. If there is no "old one" (in upstream QEMU)
> > at all, then there is nothing to keep and deprecate.
>
> I think the commit message of the xen.git commit should explain what
> options are supported by which versions of qemu (including qemu
> upstream's future plans).
>
> That would provide (a) something which summarises the communication
> etc. with qemu upstream and can be checked with them if necessary and
> (b) something against which the libxl changes can be easily judged.

Sorry, looks I'm misleading this to everyone.

Here I picked my reply from another email:

Actually qemu upstream never own this option, '-gfx_passthru' at all. 
This just exists alone in qemu-xen-traditional. So here I'm trying to 
introduce a new stuff that doesn't clash anything in qemu upstream.

So I guess I should rephrase this as follows:

    libxl: add one machine property to support IGD GFX passthrough

    When we're working to support IGD GFX passthrough with qemu
    upstream, we'd like to introduce a machine option,
    "-machine xxx,igd-passthru=on", to enable/disable that feature.
    And we also remove that old option, "-gfx_passthru", just from
    the case of LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN since actually
    no any qemu stream version really need or use that.

So is it good?

Thanks
Tiejun