[Qemu-devel] qemu-system-* using mmap?

[Tim Olson <tim@io.com>]

I am using qemu 0.8.2 built from source.  In the qemu technical 
documentation for features under full system emulation, it says:

"QEMU can either use a full software MMU for maximum portability or use 
the host system call mmap() to simulate the target MMU."

However, I cannot find a way to build a full system simulator which 
does not define SOFTMMU -- in fact, the configure parameters 
"--disable-system" and "--enable-system" directly control the softmmu 
switch.  There are some mmap() calls in the kqemu code, but to use that 
requires full kqemu support code in the kernel.

I think there is a big performance hit using the software mmu, as each 
target load or store instruction is expanded into 20-30 host 
instructions to perform the translation.  Is there a way to build the 
qemu-system-* emulators using the mmap() feature mentioned in the 
documentation?

	-- Tim Olson