Re: [Qemu-devel] [PATCH] 64 bit I/O support v7

[Jamie Lokier]

Blue Swirl wrote:
> - Small writes cause a read-modify-write cycle, but I think that may
> happen with real devices too. Another solution is to write zero in
> other byte lanes without reading.

On PCI and I think most buses, there are separate byte-enable pins for
writing each byte lane and the hardware can decide to ignore the
unenabled bytes or not.

-- Jamie