Re: [RFC 1/2] vfio/pci: keep the prefetchable attribute of a BAR region in VMA

From: Will Deacon
Date: Tue May 04 2021 - 04:30:15 EST

On Mon, May 03, 2021 at 10:03:59PM +0000, Vikram Sethi wrote:
> Will/Catalin, perhaps you could explain your thought process on why you chose
> Normal NC for ioremap_wc on the armv8 linux port instead of Device GRE or other
> Device Gxx.

I think a combination of: compatibility with 32-bit Arm, the need to
support unaligned accesses and the potential for higher performance.

Furthermore, ioremap() already gives you a Device memory type, and we're
tight on MAIR space.