1 min read
In short
QEMU 11.1.0 is useful for more than emulation: it can run ARM programs on x86 and work in virtualisation mode at nearly hardware speed. But those scenarios rest on different mechanisms, and their expectations should not be mixed.
When you need to run an ARM program on an ordinary x86 computer, the question comes down not to the operating system but to the processor architecture. QEMU 11.1.0 solves that through emulation — the application runs in an environment that reproduces a different hardware platform.
That is QEMU's main practical value: you can run code built for one architecture on a system with a completely different one. The approach is convenient for testing programs and working with environments you do not physically have to hand.
But QEMU has another mode as well — virtualisation. Here the code executes directly on the CPU, and the isolated environment gets support from the Xen hypervisor, the KVM module in Linux or NVMM in NetBSD. So performance can be close to that of a hardware system.
And here the caveat matters: emulation and virtualisation are not the same thing. The first gives portability between architectures, the second high speed where the platform allows instructions to be executed directly. You cannot automatically expect running an ARM program on x86 to deliver the same performance as a virtual machine on compatible hardware.
Which matters more to you right now: the ability to run a foreign architecture, or the speed of an isolated environment on your own system?