On Fri, Jun 12, 2015 at 03:05:10PM +0100, Frediano Ziglio wrote:
> This patch allow to limit number of heads using qxl driver. By default
> qxl driver is not limited on any kind on head use so can decide to use
> as much heads.
> 
> 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).
> 
> 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.
> 
> Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
> ---
>  hw/display/qxl.c | 26 +++++++++++++++++++++-----
>  hw/display/qxl.h |  3 +++
>  2 files changed, 24 insertions(+), 5 deletions(-)
> 
> Change from v1:
> - check spice-server version.
> 
> diff --git a/hw/display/qxl.c b/hw/display/qxl.c
> index b220e2d..d6e9369 100644
> --- a/hw/display/qxl.c
> +++ b/hw/display/qxl.c
> @@ -272,6 +272,12 @@ static void qxl_spice_monitors_config_async(PCIQXLDevice *qxl, int replay)
>                      QXL_COOKIE_TYPE_POST_LOAD_MONITORS_CONFIG,
>                      0));
>      } else {
> +#if SPICE_SERVER_VERSION >= 0x000c06 /* release 0.12.6 */
> +        if (qxl->max_outputs) {
> +            spice_qxl_set_monitors_config_limit(&qxl->ssd.qxl,
> +                                                qxl->max_outputs);
> +        }
> +#endif
>          qxl->guest_monitors_config = qxl->ram->monitors_config;
>          spice_qxl_monitors_config_async(&qxl->ssd.qxl,
>                  qxl->ram->monitors_config,
> @@ -992,6 +998,7 @@ static int interface_client_monitors_config(QXLInstance *sin,
>      PCIQXLDevice *qxl = container_of(sin, PCIQXLDevice, ssd.qxl);
>      QXLRom *rom = memory_region_get_ram_ptr(&qxl->rom_bar);
>      int i;
> +    unsigned max_outputs = ARRAY_SIZE(rom->client_monitors_config.heads);
>  
>      if (qxl->revision < 4) {
>          trace_qxl_client_monitors_config_unsupported_by_device(qxl->id,
> @@ -1014,17 +1021,23 @@ static int interface_client_monitors_config(QXLInstance *sin,
>      if (!monitors_config) {
>          return 1;
>      }
> +
> +#if SPICE_SERVER_VERSION >= 0x000c06 /* release 0.12.6 */
> +    /* limit number of outputs based on setting limit */

« based on 'max_outputs' command line parameter » maybe ?

Patch looks good to me.

Christophe