Comment 19 for bug 1180419

I'm seeing this too and its highly reproducible (just click Action -> Shutdown in Virtual Machine Connection). It causes the VM to hang and for its disks to go offline (network connections will fail too). For those searching the net, my backtrace is attached (for anyone else wondering how to get such a backtrace set up COM1 to use a named pipe (e.g. ubuntu) in Hyper-V Manager, connect to the pipe using a program like Tera Term and add console=ttyS0,115200n8 to grub).

To me this looks like the issue that was fixed by https://patchwork.kernel.org/patch/2027361/ which seems to be part of the patch series mention in https://lkml.org/lkml/2013/1/23/570 . This patch is not in 3.8.13 stable kernel ( http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/log/drivers/hv/hv_util.c?h=linux-3.8.y ). The patch did go mainstream eventually (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/hv/hv_util.c?id=3dd6cb497198a0533a2530b6a345c60c9a29b9bc in the 3.9 kernel (git describe --contains 3dd6cb497198a0533a2530b6a345c60c9a29b9bc returns v3.9-rc1~124^2~27).

Fedora 18's 3.8.9-200 kernel has the same problem as Ubuntu Raring's 3.8.9.0-19 kernel but Fedora 18's 3.9.6-200 does not have this issue.