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 10:17, Avi Kivity wrote:
> On 09/14/2011 10:42 AM, Alexander Graf wrote:
>> On 14.09.2011, at 09:11, Avi Kivity wrote:
>>
>>>  On 09/13/2011 10:39 PM, Blue Swirl wrote:
>>>>  >
>>>>  >   Here is the problem: Both the vram and the ISA range get mapped into
>>>>  >   system address space, but the former eclipses the latter as it shows 
>>>> up
>>>>  >   earlier in the list and has the same priority. This picture changes 
>>>> with
>>>>  >   the chain-4 alias which has prio 2, thus maps over the vram.
>>>>  >
>>>>  >   It looks to me like the ISA address space is either misplaced at
>>>>  >   0x80000000 or is not supposed to be mapped at all on PPC. Comments?
>>>>
>>>>  Since there is no PCI-ISA bridge, ISA address space shouldn't exist.
>>>
>>>  Where does the vga device sit then?
>>
>> On the PCI bus? :)
>>
> 
> I thought it was std vga, which is an ISA device.

There are both types (ISA-only and PCI).

> 
> 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.

Jan

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