Re: [Qemu-devel] [PATCH v2] RFC: qxl: allow to specify head limit to qxl driver

[Gerd Hoffmann]

On Do, 2015-06-11 at 10:38 +0100, Frediano Ziglio wrote:
> libvirt has this as a video card parameter (actually set to 1 but not
> used). This parameter will allow to limit setting a use can do (which
> could be confusing).

Hmm.  So heads is '1' by default but ignored today.  When this starts to
be actually applied that will break existing multihead setups I suspect.

> This patch rely on some change in spice-protocol which are not still
> accepted. See
> http://lists.freedesktop.org/archives/spice-devel/2015-June/020221.html.

Spice-server changes, right?
Needs #ifdefs so qemu continues to build with old spice-server versions.
The spice-server changes need to be upstream first.

Also: when we pass on the limit to spice-server anyway spice-server can
take care to apply the limit both ways and not call the
->client_monitors_config() callback with more than $limit monitors.  Has
the advantage to reduce the test matrix:  Limit either works or doesn't.
There will be no spice-server/qemu version combination where the limit
is applied one way only.

  Gerd