Re: [Qemu-devel] [PATCH v2 2/2] warn about two vga cards

[Philippe Mathieu-Daudé]

On 07/03/2018 03:25 AM, Gerd Hoffmann wrote:
> On Mon, Jul 02, 2018 at 02:03:58PM -0300, Philippe Mathieu-Daudé wrote:
>> On 07/02/2018 01:43 PM, Gerd Hoffmann wrote:
>>> On Mon, Jul 02, 2018 at 06:33:45PM +0200, Gerd Hoffmann wrote:
>>>> Two vga cards will try to register for the same legacy (isa) ioports.
>>>> Due to this conflict only one of the two cards will work correctly in
>>>> vga mode.
>>>>
>>>> Print a warning message in that case.  Also try registering the ports
>>>> only once, so the first vga added to the system will work properly.
>>>
>>> Scratch that, not working as expected.
>>
>> Uh what's wrong?
> 
> Well, current behavior (with patch 1/2 applied, or with virtio-vga
> which doesn't use global_vmstate) is "last vga card wins", and that card
> actually works.  This patch breaks the vga display, even when tweaked
> that both vga and vbe ports are handled (so they don't end up being
> assigned to two different cards).  Didn't figure yet why.

With this patch the I/O registered is "first vga card wins", maybe there
is now a discrepancy...

> 
> Beside that I've noticed cirrus-vga doesn't use that function, so even
> the warning message doesn't work as intended in case cirrus is involved.

Oh... weird, OK.

Regards,

Phil.