Re: [Qemu-devel] [PATCH 6/6] kvm: qemu: fix vga screendump

[andrzej zaborowski]

2008/7/20 Anthony Liguori <address@hidden>:
> andrzej zaborowski wrote:
>>
>> 2008/7/20 Anthony Liguori <address@hidden>:
>>
>>>
>>> andrzej zaborowski wrote:
>>>
>>>>
>>>> 2008/7/20 Anthony Liguori <address@hidden>:
>>>>  With -no-graphic there's no ds->data, or it can have lower bpp than
>>>> what's otherwise available.
>>>>
>>>>
>>>
>>> Screen dumping with -no-graphic probably should just show a black screen
>>> anyway.
>>>
>>
>> I thought this was the main use case. You shouldn't need sdl installed
>> to perform the tests Avi talked about.
>>
>
> You could still just do -vnc none to achieve the same effect.

What I mean is it should be totally independent of that and of X on
host, if you want to perform comparisons on the bitmaps (and for
various other reasons).

>
>>> I don't think a lower depth is really that big of a deal.  It's what the
>>> user would be seeing anyway.  The simplicity seems really nice to me.
>>>
>>>
>>>>>
>>>>> I think your patch looks better, but I can also code up a new screen
>>>>> dumping
>>>>> mechanism that doesn't take over DisplayState unless I'm missing
>>>>> something
>>>>> obvious.
>>>>>
>>>>>
>>>>
>>>> It's worth a try, dumping ds->data is perhaps the way to go but
>>>> ds->depth is being set to 32bit and various video cards are optimised
>>>> on the assumption that ds->depth doesn't change, so maybe there should
>>>> be a notification callback.
>>>>
>>>>
>>>
>>> Yeah, that's a bug BTW and AFAIK it's only a problem with VMware VGA.
>>>
>>
>> AFAIK also at least three other adapters.
>>
>
> Really?  Which ones?  I think both std-vga and cirrus are fine.

PXA270 lcdc, epson blizzard and s3c2410 lcdc (currently in
svn.openmoko.org only). It's easy to add notifications in these. In
VMware SVGA the guest needs to be somehow notified, it's possible the
guest polls the depth register already.

Regards