Re: [Qemu-devel] The QEMU Accelerator Module

[Derek Fawcus <dfawcus@cisco.com>]

Well,
  rather than whinging because Fabrice has not chosen to distribute his
work under your preferred licence.  People could simply reimplement it.

Mind - this involves effort on their behalf,  and some thinking.  So it's
certainly easier to moan.  However I suggest that such moaning is simply
a waste of time and effort.

Now I don't know how Fabrice has done the kqemu module,  but the obvious
approach that springs to mind is simply moving the qemu-fast processing
into the kernel with checks for the address boundary.  So if I was to
attempt to reimplement it,  my starting point would be to approach it
in that fashion.

Namely placing a version of cpu_exec() and/or main_loop() into the kernel
together with the use of the USE_CODE_COPY facility and some bounds checks
such that if the machine being emulated attempted to have accessable memory
above 0xc0000000 it would fall back to the user-space SOFT_MMU emulation.
One could then manipulate the process space such that while the kernel
module was running user space code,  it's process address space (< 0xc0000000)
reflected the emulated machine space.

However,  I've got other things to do,  so the above is not a priority,
and I'm quite happy to use Fabrice's module.  Mind - I need to update
to a more recent version of the code,  my current work is in a version
dating back to ~ September / October last year.

DF