On Mon, Nov 6, 2023 at 12:46 PM Matthew Dharm <mdharm-usb@xxxxxxxxxxxxxxxxxx> wrote: > > > Special MMIO reservation in BIOS is not required if a device in your > PCIe tree, such as a Broadcom Gen4 or Gen5 switch device, can reserve > address space via "synthetic mode" for missing devices. > > Matt Yes, I'm familiar with Synthetic Mode (or Synthetic Endpoints), but that's simply creating a dummy device to fool the BIOS into effectively putting aside some amount of MMIO space. And that works great so long as what you want to dynamically add fits within that reserved space. I guess I was looking for something more flexible where I didn't need to know a priori the "size" of what I wanted to add in. Presumably this would require some kind of rebalancing of the address assignments within the PCIe tree/sub-tree, which in turn likely means temporarily "suspending" I/O activity, at least across some portion of the I/O tree, while addresses move around. Eric
