Fabrice Bellard writes ("[Qemu-devel] Re: [PATCH 1/6] Use correct types to enable > 2G support"): > Paul Brook wrote: If we ever implement >2G ram on a 32-bit host this > > may need some rethinking. We can deal with that if/when it > > happens though. Requiring a 64-bit host for large quantities of > > ram seems an acceptable limitation (N.B. I'm only talking about > > ram size, not target physical address size). > > I agree.
This demonstrates quite nicely why we need to get rid of the assumption that all guest memory is mapped by the host. The configuration with a 32-bit host (dom0), 64-bit guest, and of course 64-bit Xen, is very common. qemu runs (currently) in the dom0. Ian.