On 10/16/2013 08:12 AM, Chris Murphy wrote:
Is a 64bit host expected to support running a 32bit guest OS in qemu/kvm? Or do archs need to match?
64-bit guets on 64-bit host exposing a 64-bit environment - works just fine; supported, uses hardware acceleration.
32-bit guest on 64-bit host exposing only a 32-bit environment - works just fine; supported, uses hardware acceleration.
32-bit guest on 64-bit host exposing a 64-bit environment - works just fine; supported, uses hardware acceleration.
32-bit guest on 32-bit host (necessarily exposing a 32-bit environment) - works just fine; supported, uses hardware acceleration (but gets less testing, as few people run virt hosts in 32-bit mode).
No support for running a 64-bit guest on a 32-bit host (hardware just doesn't expose enough memory).
Cross arch testing - works just fine, but slower (uses qemu emulation rather than hardware accelation), and a bit harder to support, but still useful; can only support a bit width in the guest <= bit width in the host.