qemu: fix machine types for various platforms

pkgs/clan-cli/clan_cli/vms/qemu.py

@@ -1,3 +1,4 @@
+import platform
 import random
 from collections.abc import Generator
 from contextlib import contextmanager
@@ -85,6 +86,44 @@ class QemuCommand:
     vsock_cid: int | None = None
 
 
+def get_machine_options() -> str:
+    """Get appropriate QEMU machine options for host architecture."""
+    arch = platform.machine().lower()
+    system = platform.system().lower()
+
+    # Determine accelerator based on OS
+    if system == "darwin":
+        # macOS uses Hypervisor.framework
+        accel = "hvf"
+    else:
+        # Linux and others use KVM
+        accel = "kvm"
+
+    if arch in ("x86_64", "amd64", "i386", "i686"):
+        # For x86_64, use q35 for modern PCIe support
+        return f"q35,memory-backend=mem,accel={accel}"
+    if arch in ("aarch64", "arm64"):
+        # Use virt machine type for ARM64
+        if system == "darwin":
+            # macOS ARM uses GIC version 2
+            return f"virt,gic-version=2,memory-backend=mem,accel={accel}"
+        # Linux ARM uses max GIC version
+        return f"virt,gic-version=max,memory-backend=mem,accel={accel}"
+    if arch == "armv7l":
+        # 32-bit ARM
+        return f"virt,memory-backend=mem,accel={accel}"
+    if arch in ("riscv64", "riscv32"):
+        # RISC-V architectures
+        return f"virt,memory-backend=mem,accel={accel}"
+    if arch in ("powerpc64le", "powerpc64", "ppc64le", "ppc64"):
+        # PowerPC architectures
+        return f"powernv,memory-backend=mem,accel={accel}"
+
+    # No fallback - raise an error for unsupported architectures
+    msg = f"Unsupported architecture: {arch} on {system}. Supported architectures are: x86_64, aarch64, armv7l, riscv64, riscv32, powerpc64"
+    raise ClanError(msg)
+
+
 def qemu_command(
     vm: VmConfig,
     nixos_config: dict[str, str],
@@ -116,13 +155,14 @@ def qemu_command(
     if not vm.waypipe.enable:
         kernel_cmdline.append("console=tty0")
     hostfwd = ",".join(f"hostfwd=tcp::{h}-:{g}" for h, g in portmap.items())
+    machine_options = get_machine_options()
     # fmt: off
     command = [
         "qemu-kvm",
         "-name", vm.machine_name,
         "-m", f'{nixos_config["memorySize"]}M',
         "-object", f"memory-backend-memfd,id=mem,size={nixos_config['memorySize']}M",
-        "-machine", "pc,memory-backend=mem,accel=kvm",
+        "-machine", machine_options,
         "-smp", str(nixos_config["cores"]),
         "-cpu", "max",
         "-enable-kvm",