Re: [Qemu-devel] dataplane bug: fail to start Windows VM with dataplane enable

[Stefan Hajnoczi]

On Tue, Mar 26, 2013 at 11:10:35PM +0800, 张磊强 wrote:
> Hi,  Paolo && Stefan:
> 
> When I test the dataplane feature with qemu master, I find that
> Windows (Windows 7 and Windows 2003) VM will hang if dataplane is
> enabled. But if I try to start a Fedora VM, it can start normally.
> 
> The command I boot QEMU is:
> x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 1024 -smp 2 -drive
> file=win7.img,if=none,id=drive-virtio-disk,format=raw,cache=none,aio=native
> -device 
> virtio-blk-pci,config-wce=off,scsi=off,x-data-plane=on,drive=drive-virtio-disk,id=virtio-disk
> 
> I found the similar bug has reported some days ago:
> http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02200.html
> . And a patch for this bug has already committed by Paolo at Mar 13:
> http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02200.html
> .
> 
> But it cannot work under my environment. Could you give me some advise
> to debug this problem ? I can provide more information if need.

Hi,
I haven't gotten to the bottom of it yet but wanted to let you know that
I'm seeing a hang at the boot screen after the installer reboots.  The
Windows logo animation runs but the guest seems unable to make progress.

Will let you know when there is a fix.  The guest I'm testing is Windows
7 Professional 64-bit.

As a workaround you can set x-data-plane=off to boot the guest for the
first time.  Subsequent boots will succeed with x-data-plane=on.

Stefan