On 19 August 2011 03:59, 陳韋任 <che...@iis.sinica.edu.tw> wrote: >> More generally and not x86-specific, there are problems with >> the multithreaded user-mode support which I suspect exist because >> nobody has ever sat down and worked out a coherent design for it, >> including what might need to be thread-local and what locking >> is required. So the result is that it mostly works but if you > > You mean some QEMU data structures need to be thread-local or lock > protected in order to emulate guest multi-threaded program correctly?
Approximately, yes (the third option being "redesign the data structure so it can be sensibly protected"). See https://bugs.launchpad.net/qemu/+bug/668799 for discussion of one example. None of this is impossibly difficult; it just requires that somebody sits down and actually works through the problems and fixes them. -- PMM