Re: [Qemu-devel] [Spice-devel] Vioserial of Windows guest OS on Qemu 0.15

[Alon Levy]

On Thu, Jan 19, 2012 at 08:09:57AM +0000, Stefan Hajnoczi wrote:
> On Thu, Jan 19, 2012 at 09:41:15AM +0800, Charles.Tsai-蔡清海-研究發展部 wrote:
> > I tested on Qemu 1.0.50. and found the VioSerial driver had problem to 
> > install on 64-bit Win7 guest.
> > During the driver installation, the system hung after the driver being 
> > installed. After I rebooted the
> > guest OS, the Vioserial driver work. The hang system seemed to be found 
> > only during the driver installation.
> 
> If you need to reproduce the installation hang I suggest using qemu
> -snapshot or qemu -drive ...,snapshot=on.  These options prevent changes
> made by the guest to the disk image from being permanent.
> 
> Once you terminate QEMU the changes will be gone and your disk image
> will be unchanged - useful for repeatedly testing these types of issues!
> 

There is an additional "trick" I use, if you add -no-shutdown then if
you find yourself wanting to save the changes anyway (say you started
with -snapshot but decided you want to keep the changes you have done),
which you can do with "commit virtio0" or "commit ide0" (depending on
the block device), it will allow you to do the commit after you shutdown
the guest, which is easier then trying to get it to unmount the disks.

> Stefan
>