The command line argument that means 'run natively' is the "-accel hvf" one, which makes QEMU use the Hypervisor.framework macOS APIs. (This is why you have to

The command line argument that means 'run natively' is the "-accel hvf" one, which makes QEMU use the Hypervisor.framework macOS APIs. (This is why you have to use an out-of-tree patchset at the moment -- mainline QEMU only supports hvf on x86 CPUs right now.) The hvf support patches don't make any attempt to make the guest CPU report different ID values or features, so regardless of what actual cpu type you ask for with -cpu the guest sees whatever the host CPU is.