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Does QEMU emulate the CPU on macOS?

• zweifuss 4y ago
  Depends. QEMU can use Apple's Hypervisor virtualization framework to run ARM64 operating systems on Apple Silicon without emulation. It seems to be possible to then use Rosetta 2 to run x64-code on those operating systems.
  • eurasiantiger 4y ago
    Can confirm this works, but some applications will be slow. Seen a magnitude of difference with x86 JVM containers between Rosetta 2 and native ARM64.
    • sirwhinesalot 4y ago
      Rosetta 2 works great for AoT stuff but for JIT you'll always end up with at least a 2x slowdown since it needs to always JIT the JVMs JIT output. That said, it working at all is pretty amazing.
      • saagarjha 4y ago
        This doesn’t mean there’s a 2x slowdown. (I’ve seen 1.5x to 5x.)
• gizmo 4y ago
  The CPU architecture of the VM and Host have to match, otherwise you get software emulation which is very very slow. It's good enough for occasional usage, but nowhere near good enough for daily development purposes.