can u try with qemu-system-x86
I do not have qemu-system-x86 on my machine. I either have qemu-system-x86_64 or qemu-system-i386 to the closest.
My machine configuration -
saket@saket-Notebook-PC:~/coreboot$ uname -a Linux saket-HP-Pavilion-g6-Notebook-PC 3.19.0-16-generic #16-Ubuntu SMP Thu Apr 30 16:09:58 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux