Re: [Qemu-devel] [PATCH] q35/mch: implement extended TSEG sizes

[Paolo Bonzini]

On 08/06/2017 21:55, Michael S. Tsirkin wrote:
> We don't have room anywhere in PCI config space. Laszlo makes argument
> why it's safe for this device based on spec but it's anyone's guess
> whether current and future software will follow spec.  In short, going
> anywhere near the emulated device has a potential to break some drivers.

There are no such drivers.  The MCH and PCH are only touched by the
firmware, not by the OS.  There are exceptions such as the Intel
graphics driver's incestuous relationship with the PCH, but they are
well known.

Let's avoid overengineering please.  The only sensible (but less
sensible) alternative is to just say it's 32MB (or 64, or 128) and cross
fingers that we won't need more.

Paolo