Re: [Qemu-devel] [PATCH] virtio-vga: only enable for specific boards

[Peter Maydell]

On Thu, 21 Mar 2019 at 14:41, Paolo Bonzini <address@hidden> wrote:
>
> When virtio-vga was added, the intention was to only support it for
> those machines where the firmware does not know about virtio-gpu,
> and supported VGA legacy hardware before virtio-{gpu,vga} were
> introduced.
>
> The Kconfig switch however enabled virtio-vga for all machines with
> a PCI bus, and libvirt then prefers it even on hardware where
> virtio-gpu would be preferrable.  At least for now, only enable
> virtio-vga for PC, hppa and pSeries machines, as was the case
> before Kconfig dependencies were introduced.

Do we have a reference to a bug report against libvirt for this?

> Reported-by: Laszlo Ersek <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  hw/display/Kconfig | 2 +-
>  hw/hppa/Kconfig    | 1 +
>  hw/i386/Kconfig    | 1 +
>  hw/ppc/Kconfig     | 1 +
>  4 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/hw/display/Kconfig b/hw/display/Kconfig
> index 86c1d544c5..72be57a403 100644
> --- a/hw/display/Kconfig
> +++ b/hw/display/Kconfig
> @@ -100,7 +100,7 @@ config VIRTIO_GPU
>
>  config VIRTIO_VGA
>      bool
> -    default y if PCI_DEVICES
> +    # defaults to "N", enabled by specific boards
>      depends on VIRTIO_PCI
>      select VGA

Could we have a comment that says what the criterion for
a board needing to enable it is, so that if we add new
boards in future we know whether they need to enable it or not?
(If the answer is "never for any new board", that's useful
to say.)

thanks
-- PMM