-----Original Message-----
No, unsharing nicely solves the problem.
We already have graphics cards with 2 GB RAM, so anything above 2 GB is unreachable during sizing. For a graphics card with 4 GB RAM, every single freaking 32bit location will be inaccessible. That means it it totally irrelevant whether you unshare or not, the machine will simply fail.
This is a good reminder that 64-bit BARs need to work. Sizing with 64-bit BARs doesn't take away the lower 4GB.
Myles