device: 0.792 socket: 0.671 files: 0.660 vnc: 0.658 network: 0.632 permissions: 0.551 PID: 0.541 boot: 0.512 other: 0.489 graphic: 0.419 semantic: 0.389 debug: 0.328 performance: 0.271 KVM: 0.176 validate_guest_space incorrectly enabled on AArch64 When running linux-user targetting AArch64, validate_guest_space() in elfload.c reserves space in the guest address space for the ARM commpage. Since there is no commpage on AArch64, this function should be disable on that target. Thanks for the bug report -- I've just submitted this patch which should fix this: http://patchwork.ozlabs.org/patch/328565/ Fix will be in 2.0.