todo

qemu虚拟机代码

short term:
----------
- support variable tsc freq
- cpu_interrupt() win32/SMP fix
- USB host async
- IDE async
- debug option in 'configure' script + disable -fomit-frame-pointer
- Precise VGA timings for old games/demos (malc patch)
- merge PIC spurious interrupt patch
- merge Solaris patch
- warning for OS/2: must not use 128 MB memory (merge bochs cmos patch ?)
- config file (at least for windows/Mac OS X)
- commit message if execution of code in IO memory
- update doc: PCI infos.
- VNC patch + Synaptic patch.
- basic VGA optimizations
- physical memory cache (reduce qemu-fast address space size to about 32 MB)
- better code fetch (different exception handling + CS.limit support)
- do not resize vga if invalid size.
- avoid looping if only exceptions
- cycle counter for all archs
- TLB code protection support for PPC
- see openMosix Doc 
- disable SMC handling for ARM/SPARC/PPC (not finished)
- see undefined flags for BTx insn
- user/kernel PUSHL/POPL in helper.c
- keyboard output buffer filling timing emulation
- return UD exception if LOCK prefix incorrectly used
- test ldt limit < 7 ?
- tests for each target CPU
- fix CCOP optimisation
- fix all remaining thread lock issues (must put TBs in a specific invalid
  state, find a solution for tb_flush()).
- fix arm fpu rounding (at least for float->integer conversions)

ppc specific:
------------
- TLB invalidate not needed if msr_pr changes
- SPR_ENCODE() not useful
- enable shift optimizations ?

linux-user specific:
-------------------
- add IPC syscalls
- handle rare page fault cases (in particular if page fault in helpers or
  in syscall emulation code).
- more syscalls (in particular all 64 bit ones, IPCs, fix 64 bit
  issues, fix 16 bit uid issues)
- use page_unprotect_range in every suitable syscall to handle all
  cases of self modifying code.
- fix thread stack freeing (use kernel 2.5.x CLONE_CHILD_CLEARTID)
- use kernel traps for unaligned accesses on ARM ?


lower priority:
--------------
- int15 ah=86: use better timing
- suppress shift_mem ops
- fix some 16 bit sp push/pop overflow (pusha/popa, lcall lret)
- optimize FPU operations (evaluate x87 stack pointer statically)
- use -msoft-float on ARM