[Spice-devel] Bug in qxl kernel driver (bpp)

[Melroy van den Berg]

Hi,

Thanks for your response.

It looks good around there:
https://gitlab.freedesktop.org/xorg/driver/xf86-video-qxl/-/blob/master/src/qxl_uxa.c#L409

There is a call within qxl_create_pixmap() towards: qxl->bo_funcs->create_surface (qxl, w, h, depth)
The 'depth' variable is properbly 1 within this function already.

That create pixmap function pointer is added to screen->CreatePixmap.
Any call could potentially put '1' into the 4th parameter, like these calls:
https://gitlab.freedesktop.org/xorg/driver/xf86-video-qxl/-/blob/master/src/uxa/uxa-render.c#L470
https://gitlab.freedesktop.org/xorg/driver/xf86-video-qxl/-/blob/master/src/uxa/uxa-render.c#L795
https://gitlab.freedesktop.org/xorg/driver/xf86-video-qxl/-/blob/master/src/uxa/uxa-glyphs.c#L161
https://gitlab.freedesktop.org/xorg/driver/xf86-video-qxl/-/blob/master/src/uxa/uxa-glyphs.c#L927
https://gitlab.freedesktop.org/xorg/driver/xf86-video-qxl/-/blob/master/src/dfps.c#L357

Regards,
Melroy van den Berg

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
Op donderdag, mei 14, 2020 11:26 AM, Frediano Ziglio <fziglio at redhat.com> schreef:

> > Hi folks,
>
> > The Xorg log is getting spammed with the following messages (I noticed I'm
> > not the only one on the Internet):
>
> > > qxl_surface_create: Bad bpp: 1 (1)
> >
> > > qxl_surface_create: Bad bpp: 1 (1)
> >
> > > qxl_surface_create: Bad bpp: 1 (1)
> >
> > I think this isn't nice for anyone. So I propose a fix in the driver around
> > here :
> > https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/qxl/qxl_cmd.c#L396
> > A valid value of Bits per pixel (bpp aka Pixelmap) is often 24 (or 32 bit
> > depth). Please try to play around with this, and see if you could make Xorg
> > server happy again.
>
> > Thanks!
>
> > Regards,
> > Melroy van den Berg
>
> Hi,
> the "bpp" value does not arrive to the kernel so there's no point to update it.
> It arrives from some other calls in the driver. I think the function to be changed
> should qxl_create_pixmap in the Xorg driver (src/qxl_uxa.c).
>
> Regards,
> Frediano