On Tue, Jan 14, 2014 at 08:50:54AM -0500, Mike Day wrote: > > "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"
The question was whether addresses such as 0xfffffffffec00000 can be a valid BAR value on these platforms, whether it's accessible to the CPU and to other PCI devices. -- MST
