Re: [Qemu-devel] [PULL 1/1] ui/vnc: fix vmware VGA incompatiblities

[Gerd Hoffmann]

  Hi,

> > -#define SVGA_MAX_WIDTH                  2360
> > +#define SVGA_MAX_WIDTH                  ROUND_UP(2360, 
> > VNC_DIRTY_PIXELS_PER_BIT)

> Here we pull in the VNC header in order to get the definition
> of the VNC_DIRTY_PIXELS_PER_BIT constant, but I don't understand
> why. The hw/display code should be agnostic of whatever the
> UI display front-end is. Why does vmware_vga.c need to care
> but not any other device?

Yep, doesn't make sense.

> I can't find anything in the vmware VGA device docs (though they
> are pretty meagre) suggesting that there's a requirement for
> the surface to be a multiple of 16, so I think that the VNC code
> needs to be able to cope. (This should be no different from any other
> display device model setting a non-multiple-of-16 width.)

We had problems with that in the past but it should be fixed now.  vnc
wants a multiple of 16 still.  IIRC you'll get a small black bar filling
the room to the next multiple of 16 in case the display surface doesn't
match.

> So my feeling is that this vmware_vga.c portion of this commit
> should be reverted,

Agree.

Maybe even deprecate the whole device?  Not sure how useful it is these
days as it has seen pretty much no development in the last decade.  The
linux kernel modesetting driver complains about missing device features
and refuses to touch the device ...

take care,
  Gerd