Re: PSA: migrating linux-hotplug to new vger infrastructure

On Mon, Nov 6, 2023 at 12:46=E2=80=AFPM Matthew Dharm
<[email protected]> 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