Hi, > Since we will not use all 256 buses of an extra PCI domain, > I think this space will allow us to support more PCI domains.
Depends on the use case I guess. If you just need many pcie devices this probably doesn't help. If you want them for numa support then yes, more domains with less devices each can be useful then. > How will the flow look like ? > > 1. QEMU passes to SeaBIOS information of how many extra > PCI domains needs, and how many buses per domain. > How it will pass this info? A vendor specific capability, > some PCI registers or modifying extra-pci-roots fw_cfg file? Where is the pxb-pcie device? 0000:$somewhere? Or $domain:00:00.0? > 2. SeaBIOS assigns the address for each PCI Domain and > returns the information to QEMU. > How it will do that? Some pxb-pcie registers? Or do we model > the MMCFG like a PCI BAR? If we can access pxb-pcie registers before configuring MMCFG then yes, we should use pxb-pcie registers for that. cheers, Gerd
