On Wed, Sep 25, 2013 at 06:51:04AM +0500, Salman Javaid wrote:
> 
> qemu-system-i386: pci_add_option_rom: failed to find romfile
> "pxe-rtl8139.rom"

you may need the 'kvm-ipxe' package.

http://packages.ubuntu.com/search?searchon=contents&keywords=pxe-rtl8139.rom&mode=&suite=precise&arch=any