Re: [Qemu-devel] [Bug 818673] Re: virtio: trying to map MMIO memory

[Rick Vernam <rickv@hobi.com>]

On Wednesday 14 September 2011 16:30:11 Rick Vernam wrote:
> On Wednesday 14 September 2011 14:42:09 vrozenfe wrote:
> > Thank you, Rick.
> > 
> > Could you help me to narrow this problem down?
> 
> Absolutely.
> 
> > As I see, you have three virtio drivers installed on your system - block,
> > net, and virtio serial. Technically, anyone of them can create "trying to
> > map MMIO memory" problem. The best way to find a buggy driver ( or
> > drivers) will be to isolate one from the other. If you can, please try
> > running only one virtio device every time to see which driver sends
> > incorrect  scatter/gather list element to QEMU.
> 
> Sure, no problem.  I'll have that in the next few days.
I started qemu without any of the virt-serial stuff, specfically:
qemu-system-x86_64 -cpu host -enable-kvm -pidfile /home/rick/qemu/hds/wxp.pid -
drive file=/home/rick/qemu/hds/wxp.raw,if=virtio,aio=native -m 1536 -name WinXP 
-net nic,model=virtio -net user -localtime -usb -vga qxl -spice 
port=1234,disable-ticketing -monitor stdio

It's been running for around 2 hours and no crash yet.

Thanks,
-Rick

> 
> > Another question. You said, the problem happens after every second or
> > third restart. Do you shutdown your VM,  or just restart it?
> 
> Have to shut down the VM guest so that the qemu process exits.
> 
> > How does it work
> > after going through several hibernate/resume, and/or suspend/resume
> > cycles.
> 
> I often will suspend with or without pausing qemu (via monitor commands
> 'stop' and 'cont').  I have never experienced any problem with the qemu
> process that was running prior to the suspend.
> 
> > Best regards,
> > Vadim.
> 
> Thanks,
> -Rik