Il 17/09/2012 19:02, Peter Maydell ha scritto: > If Xen requires 64 bit physaddrs it should probably just be asserting > this here, not randomly changing target_phys_bits. In fact all the > supported Xen target archs already have 64 bit physaddrs, so it's > harmless. But if there ever were a target Xen arch which didn't support > 64 bit phys addrs then the right approach would be to convert it to > do so regardless of whether we were using Xen or not.
No, Xen does not require 64-bit physaddrs, but it supports them even if you build it for 32-bit. Memory is accessed through a "hole" (the mapcache) provided by the hypervisor, so that a 32-bit QEMU address space is enough to run 64-bit guests. At least that's my understanding. Paolo
