On (Thu) 08 May 2014 [15:36:13], Paolo Bonzini wrote: > Il 08/05/2014 15:30, Amit Shah ha scritto: > >On (Thu) 08 May 2014 [15:14:26], Paolo Bonzini wrote: > >>Il 08/05/2014 15:02, Amit Shah ha scritto: > >>>>>I tried the patch below. Unfortunately it seems to cause qemu to crash. > >>>This doesn't remove the memory_region_transaction_begin() and > >>>_commit() from memory_region_add_eventfd(), which will still be > >>>called. > >> > >>That's correct, transactions can be nested. > > > >But each _commit() will add to the delay? > > No, only the outermost one.
Helps to read the code :-) Chris, I just tried a simple test this way: ./x86_64-softmmu/qemu-system-x86_64 -device virtio-serial-pci -device virtserialport -S -monitor stdio -nographic and it didn't crash for me. This was with qemu.git. Perhaps you can try in a similar way. Amit