I am using qemu-kvm, cli as the following: qemu-system-x86_64 -drive file=test-notes.img,if=virtio,cache=none,boot=on -net nic,macaddr=00:00:00:11:22:88,model=virtio -net tap -m 1024 -vnc :3 I open powerpoint 2007, and drag a rectangel, it moves very slowly. it must meet the following conditions to produce the same result: (1) lotus notes is running. (2) logon through rdestktop. if I connect through vnc, it will not happen; if I don't run louts notes, it will not happen. if I change to 2 vcpus as the following cli, it will respond much better. qemu-system-x86_64 -drive file=test-notes.img,if=virtio,cache=none,boot=on -net nic,macaddr=00:00:00:11:22:88,model=virtio -net tap -m 1024 -vnc :3 -smp 2 I first doubt that maybe it's from windows internal problem, so I tested on a uni-processor PC, but It looks good. I also run qemu-kvm with -no-kvm, it produce the same results. I run kvm-stat when dragging a rectangle, the output is as the following: exits 4650520 24645 insn_emulation 3508180 15158 host_state_reload 1273409 13999 io_exits 1031465 13504 irq_injections 179104 2629 hypercalls 131481 2084 halt_wakeup 33589 495 halt_exits 33584 495 irq_exits 105020 237 pf_fixed 449879 106 fpu_reload 16852 54 mmio_exits 46426 1 mmu_cache_miss 9985 0 mmu_shadow_zapped 11736 0 signal_exits 2145 0 remote_tlb_flush 251 0 it seems that qemu-kvm is emulating some instruction which take much cpu resource, but I don't know how to find the emuated instructions. Any suggestions? thanks. Regards. Green. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html