[Qemu-devel] virtqueue corruption in emulation mode?

[Sinha, Ani]

Hi Guys :

I am using the virtqueue (virtqueue_pop, virtqueue_push etc) in the emulated 
mode (non-kvm mode) from an IO thread (a separate thread different from main 
QEMU thread). What I am observing is that the virtqueue memory seems to get 
corrupt. Either qemu crashes while performing virtqueue_push() 
(virtqueue_push() -> virtqueue_fill() 
->bring_used_idx()->lduw_phys()->qemu_get_ram_ptr()->"bad ram offset") or 
crashes when the guest accesses a bad memory while using virtqueue. Now this 
never ever happens when I run QEMU in KVM mode (/dev/kvm present) OR when I use 
my functions from within the main qemu thread. I am unable to figure out why 
this is happening. I have looked into my code over and over again and I can't 
seem to explain this behavior. Can any of you guys give me any inkling?

Thanks a lot in advance.
ani


============================================================
The information contained in this message may be privileged
and confidential and protected from disclosure. If the reader
of this message is not the intended recipient, or an employee
or agent responsible for delivering this message to the
intended recipient, you are hereby notified that any reproduction,
dissemination or distribution of this communication is strictly
prohibited. If you have received this communication in error,
please notify us immediately by replying to the message and
deleting it from your computer. Thank you. Tellabs
============================================================