[Qemu-devel] Re: [PATCH] Don't explicitly set BAR values for VMware VGA

[andrzej zaborowski]

On 22/02/2008, Anthony Liguori <address@hidden> wrote:
> Right now we set explict base addresses for the PCI IO regions in the VMware
>  VGA device.  We don't register the second region at all and instead directly
>  map the physical memory.
>
>  The problem is, the addresses we're setting in the BAR is not taken into
>  account in the e820 mapping.
>
>  This patch removes the explicit BARs and registers the second region through
>  the normal PCI code.
>
>  I've only tested with a Linux guest and the open source VMware VGA driver.

I have a very similar patch on my HD but I haven't included it because
it causes my testing Ms Windows install to stop detecting the card.  I
just tested your patch and the same thing happens, i.e. with the patch
it works as a vga card but is detected as an Unknown adapter and only
the 640x480x8 mode can be used.  I can't explain this.

Currently the io port numbers can be set by the guest and the memory
io regions are fixed.  Earlier both settings were hardcoded.  This is
because in one version of the X driver (which was/is the only
documentation available) these settings were metioned as *the* correct
values for this card.  This may of course cause different types of
breakage but so far worked ok, except when it was found that in
various combinations qemu segfaulted due to different PCI cards
registering the same port range as our default.  When this happened I
tried to make these settings settable through PCI registers but found
that this broke Ms Windows.  Luckily Ms Windows still worked if only
port ranges were assigned dynamically and the segfault went away so I
left it at this but it perhaps needs better looking at.
-- 
Please do not print this email unless absolutely necessary. Spread
environmental awareness.