[Qemu-devel] Allocate PCI MMIO without BAR requests.

[David kiarie]

Hi all,

Some efforts to emulate AMD IOMMU have being going over the past few months.

In real hardware AMD IOMMU is implemented as a PCI function. When
emulating it in Qemu we want to allocate it MMIO space but real AMD
IOMMU manage to reserve memory without making a BAR request, probably
through a static address that's written by the device.(This is
something similar to what non-PCI bus devices do).Trying to reserve
memory via a BAR request results in address conflicts(in Linux) and
all other PCI devices reserve platform resources via BAR requests.

I would like to hear suggestions on how to reserve a memory region for
the device without making a BAR request.

Cheers,
David.