[Qemu-devel] Information flow tracking extension for qemu

[G Portokalidis]

Hi,
I've started looking at the source code to figure the best way to
write the extension, and I figures out it is best to write it as a new
target CPU based on the i386.

I'm adding some instrumentation code in op.c, which should make things
a bit slower but hopefully not too slow.

There are two points that I'ld like, if possible, to be clarified.

1. The FPU
The FPU has a stack defined in CPU.h, which i guess is used for
private storage by the FPU itself. What is the flow of data between
this stack (stN) and the temporary state variable (FT0 or A0)?
Is the stack data dependent on FT0? Will it ever write data to FT0
without using it as an input before? Is there any other exchange with
other registers or memory directly?

2. The Soft-MMU
I'm having trouble distinguishing where are virtual page addresses
translated to physical addresses. I would like to be able to monitor
the virtual addresses that are being loaded/stored. The right place to
do it seems to be softmmu_header.c or/and softmmu_template.c

Thanx, for the help