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

[Jan Kiszka]

On 2011-09-14 10:27, Alexander Graf wrote:
> 
> On 14.09.2011, at 10:24, Jan Kiszka wrote:
> 
>> On 2011-09-14 10:22, Avi Kivity wrote:
>>> On 09/14/2011 11:20 AM, Jan Kiszka wrote:
>>>>>
>>>>> Anyway PCI supports the vga region at 0xa0000-0xc0000.  Where is it
>>>>> supposed to be mapped?
>>>>
>>>> ...but not all PCI bridges make use of this feature / forward legacy
>>>> requests.
>>>>
>>>
>>> Then this should be fixed in the bridge?
>>
>> Yes, it's a PPC bug.
> 
> So how does the bridge not forward it then?

On real HW, by keeping the "VGA Enable" bit off. Or just not issuing
requests to the a0000..bffff range.

Under QEMU, I would simply provide the VGA model a memory region for
legacy stuff that remains unregistered.

Jan

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