Re: Guidance on emulating "sparse" address spaces

[Jason Thorpe]

> On Jun 23, 2021, at 5:42 PM, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> 
>> I'm trying to wrap my head around how to achieve this in Qemu.  I don't see 
>> an obvious way from my initial study of how the PCI code and memory regions 
>> work.  Some guidance would be appreciated!
> 
> Is bitband_ops[] useful? (see hw/arm/armv7m.c)

Thanks for the pointer!  Yes, it seems like that might be similar to what I 
need... create new address spaces (rather than using the "system" address 
space) for the PCI memory and I/O regions (I need to do this for PCI 
configuration space, too, FWIW...), then in my sparse ops handlers, decode the 
bus address and size, and then call address_space_{read,write}().  Have I got 
the gist of it?

-- thorpej