Re: [Qemu-devel] [RFC] Virt machine memory map

[Alexander Graf]

> Am 22.07.2015 um 08:52 schrieb Pavel Fedin <address@hidden>:
> 
> Hello!
> 
>>> I think the theory we discussed at the time of putting in the PCIe
>>> device was that if we wanted this we'd add support for the other
>>> PCIe memory window (which would then live at somewhere above 4GB).
>>> Alex, can you remember what the idea was?
>> 
>> Yes, pretty much. It would give us an upper bound to the amount of RAM
>> that we're able to support, but at least we would be able to support big
>> MMIO regions like for ivshmem.
> 
> But i currently think that specification of "Generic PCI host" assumes only a 
> single MMIO region + single PIO region + single ECAM. And we cannot have two 
> MMIO regions without changing its specification, which can be problematic. Am 
> i wrong about this ?

At least on Seattle we do have several regions with that driver and I don't 
expect real hardware to provide a model as simple as ours. So yes, I would be 
very surprised if there were limitations about the split of regions.


Alex

> 
> Kind regards,
> Pavel Fedin
> Expert Engineer
> Samsung Electronics Research center Russia
> 
>