[libvirt] [PATCH RFC 0/3] allow setting video ram size for graphics

[Gerd Hoffmann]

On Do, 2014-06-12 at 07:22 +0000, Wangrui (K) wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=1076098
> 
> Zeng Junliang (3):
>   For vga/cirrus/vmvga/qxl device, qemu supports commandline
>   parameter "vgamem_mb" to specifie the size of the
>   framebuffer portion of the "ram" region. As the vram attribute
>   in libvirt is only valid for qxl device in KVM/QEMU to specifie the total
>   size of the "vram" region, we expect a new attribute in libvirt.
>   The following patches introduce "vgamem" attribute to make 
>   vgamem_mb configurable in libvirt xml.

Adding a new vgamem attribute looks good to me.  Things will be more
consistent then and it will certainly be less confusion than trying to
use vram instead.

The vgamem attribute makes sense for vga, vmvga and qxl.  Please leave
out cirrus.  It is pointless to assign more memory to cirrus, guests
would not use it anyway.

Removing the confusing vram=9216 default which gets added for cirrus and
stdvga and which is never ever used would be nice too.

While touching the vga code anyway you might consider adding support for
the new '-device secondary-vga' (currently in master / will be in qemu
2.1).  That is simliar to stdvga (i.e. it has a vgamem_mb property too).
It doesn't occupy the standard vga ports though, so it can be used as
secondary display device, like qxl.

cheers,
  Gerd