[Qemu-devel] How QEMU handle precise exception?

[陳韋任]

Hi all,

  I would like to know how QEMU handle precise exception. Basically, QEMU need
to maintain a well-defined guest architecture state (register + memory) before
returning to the exception handler.

  For the guest register, does QEMU save the guest registers (except guest pc)
before every guest instruction which might raise exception? For the guest 
memory,
is it because how QEMU does (see below) so that guest memory is in a consistent
state when guest exception occured?

  - Emulate guest "store" memory operations in the same order as in the original
    program order.

  - Emulate all potentially trapping guest instructions in the same order with
    respect to the guest store instructions. 
  

  Thanks!

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj