device: 0.890
graphic: 0.846
instruction: 0.729
semantic: 0.498
mistranslation: 0.484
network: 0.474
socket: 0.472
boot: 0.416
other: 0.359
vnc: 0.354
assembly: 0.151
KVM: 0.056

Attaching WinDbg to a Windows guest on Windows host causes hang
Description of problem:
Attempting to attach WinDbg to a Windows guest on a Windows host causes qemu to lockup while using real serial ports. This has been an issue for some time (years if I'm remembering correctly) I just haven't reported it.
Steps to reproduce:
1. Enable debug in Windows guest
2. Create a DB9 between 2 COM ports
3. Power guest
4. Attach WinDbg to 2nd COM port not in use by the guest
Additional information: