device: 0.716 instruction: 0.709 graphic: 0.665 semantic: 0.553 mistranslation: 0.533 socket: 0.530 network: 0.499 vnc: 0.499 boot: 0.428 other: 0.256 KVM: 0.232 assembly: 0.152 qemu core dumps with -serial mon:vc qemu 1.5.2-1 dumps core when asked to put the monitor on a virtual console. For example, suppose you want to monitor the second serial port, you might try something like: qemu-system-x86_64 -serial null -serial mon:vc But that creates a core dump. In fact, even re-creating what should be the default dumps core: $ qemu-system-x86_64 -serial mon:vc:80Cx25C Segmentation fault (core dumped) I'm not including a backtrace because the bug is so easy to reproduce, but I can provide more info if necessary. Hi, This problem has been solved by commit 7b7ab18d0b9769b5f39e663fa55caed461b1202e: Author: Michael Roth