cpu model Intel Xeon E5405
bug detected in qemu-kvm 1.1.2-r2
host kernel version 3.2.21
host kernel arch x86_64
guest - Windows Server 2003 R2 32-bit
Guest was create with 1 cpu. When I add 1 cpu more, Windows Server detecting new multiprocessor with ACPI and install driver for him. After reboot guest system show black screen after BIOS and not booting, but qemu-kvm not crash and normaly work. I set cpu=1 for guest in options and system normaly boot.
I did downgrade qemu-kvm to version 1.1.1-r1 and guest normaly boot and work with 1 cpu and 2 cpu.