Re: [Qemu-devel] [PATCH v3 5/6] vga: Use linear mapping + dirty logging in chain 4 memory access mode

[Jan Kiszka]

On 2011-08-25 13:19, Avi Kivity wrote:
> On 08/25/2011 01:51 PM, Jan Kiszka wrote:
>>>
>>>  Plain F15 is slow.  SR2 = SR4 = 0.
>>
>> So it's not using chain4 mode. Can you check what mode the adapter is
>> actually in and how VRAM is accessed? Likely, there is nothing we can do
>> about it. /me just wonders what makes F15 grub behave differently from
>> other distro's versions...
>>
> 
> Do you remember offhand which registers I need to look at?

No, just that there are quite a few. You could check e.g.
http://www.osdever.net/FreeVGA/vga/vga.htm for descriptions. Also check
what paths the mmio handlers take.

> 
> We need a collection of gdb scripts to find a qdev, dump the memory 
> hierarchy, look up gpas, and get info about specific devices.

...or finally have a "device-show" monitor command to dump the device
state. More stable /wrt QEMU internals.

Jan

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