"Michael S. Tsirkin" <m...@redhat.com> writes: > On Fri, Jan 10, 2014 at 08:31:36AM -0700, Alex Williamson wrote:
> Short term, just assume 48 bits on x86. > > We need to figure out what's the limitation on ppc and arm - > maybe there's none and it can address full 64 bit range. > > Cc some people who might know about these platforms. The document you need is here: http://goo.gl/fJYxdN "PCI Bus Binding To: IEEE Std 1275-1994" The short answer is that Power (OpenFirmware-to-PCI) supports both MMIO and Memory mappings for BARs. Also, both 32-bit and 64-bit BARs are required to be supported. It is legal to construct a 64-bit BAR by masking all the high bits to zero. Presumably it would be OK to mask the 16 high bits to zero as well, constructing a 48-bit address. Mike -- Mike Day | "Endurance is a Virtue"
