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

[Charles . Tsai-蔡清海-研究發展部]

Alon,

Thank you for your information and we will use it if we need to find the bug 
next time.

-----Original Message-----
From: Alon Levy [mailto:address@hidden 
Sent: Thursday, January 19, 2012 7:26 PM
To: Stefan Hajnoczi
Cc: Charles.Tsai-蔡清海-研究發展部; qemu-devel; Michael Roth; Vadim Rozenfeld; 
address@hidden; Alex Huang-黃必賢-研究發展部
Subject: Re: [Qemu-devel] [Spice-devel] Vioserial of Windows guest OS on Qemu 
0.15

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
>