macOS: current Lilu/VirtualSMC/WhateverGreen/RestrictEvents, no isa-applesmc

The OSX-KVM ESP ships Lilu 1.6.8 / VirtualSMC 1.3.3 / WhateverGreen 1.6.7,
which disable themselves on macOS 26; Apple's SMC driver then runs on QEMU's
isa-applesmc stub and the restart path panics (SMCWDT smcWriteKey
kSMCBadCommand → nested panic after MACH Reboot). Overlay pinned current
releases (upstream.json opencore.kexts) and drop isa-applesmc: with the stub
present VirtualSMC steps aside ("multiple devices present"); alone it carries
the OSK and reboots work (PE restart test: 10 s, clean). RestrictEvents with
revpatch=memtab silences MacPro7,1's "Memory Modules Misconfigured".

- makeOpenCore: kext overlay + Kernel.Add entries for overlaid kexts,
  --memory-mb (4 DIMMs), bootArgs default revpatch=memtab
- qemu.nix: deviceArgsFor { appleSmc } (default false); cli: --applesmc for
  images built before this change
- vm-driver: reboot-death detection (reset 60 s after a guest reboot request
  that never comes back), panics wait for XNU's own auto-reboot, debug dir
  works across nixbld users
- generalize: QEMU USB keyboard declared ANSI (no Keyboard Setup Assistant)
- README: architecture, reliability handling, debugging

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XsESshRCoBoUVWV9qKURUF

lib/images/macos/helpers/makeImage.nix

@@ -20,7 +20,7 @@
   cpu ? qemu.defaultCpu,
   model ? "MacPro7,1",        # SMBIOS model; must be supported by the installed macOS
   seed ? name,                # MAC address + SystemUUID are derived from this
-  bootArgs ? "keepsyms=1",
+  bootArgs ? "keepsyms=1 revpatch=memtab",
   vncDisplay ? null,          # e.g. ":10" to watch the install on port 5910
   timeout ? 4 * 3600,         # seconds for the whole install
   extraOpenCoreConfig ? {},   # merged into config.plist

lib/images/macos/helpers/makeOpenCore.nix

@@ -13,7 +13,7 @@
   uuid,
   serial ? null,
   mlb ? null,
-  bootArgs ? "keepsyms=1",
+  bootArgs ? "keepsyms=1 revpatch=memtab",
   resolution ? "1024x768",
   showPicker ? true,
   pickerTimeout ? 2,
@@ -22,6 +22,12 @@
 }:
 let
   ocImage = pkgs.fetchurl { inherit (upstream.opencore.image) url sha256; name = "OSX-KVM-OpenCore.qcow2"; };
+  # OSX-KVM's ESP ships Lilu 1.6.8 / VirtualSMC 1.3.3 / WhateverGreen 1.6.7, which
+  # disable themselves on macOS 26 ("unsupported operating system"); without
+  # VirtualSMC, macOS' restart path panics on QEMU's SMC stub. Overlay the
+  # current releases (upstream.opencore.kexts, pinned).
+  kextZips = lib.mapAttrsToList (n: k: { name = n; zip = pkgs.fetchurl { inherit (k) url hash; }; })
+    (upstream.opencore.kexts or {});
 in
 pkgs.runCommand "${name}-esp" {
   nativeBuildInputs = with pkgs; [ _7zz python3 mtools dosfstools gptfdisk jq macserial ];
@@ -45,13 +51,23 @@ pkgs.runCommand "${name}-esp" {
   mkdir -p $out/EFI/vmix
   cp -r esp/EFI/BOOT esp/EFI/OC $out/EFI/
   chmod -R u+w $out/EFI
+  ${lib.concatMapStringsSep "\n" (k: ''
+    echo "=== vmix: updating ${k.name}.kext from ${k.zip.name} ==="
+    rm -rf kext-${k.name}; mkdir kext-${k.name}
+    ${pkgs.unzip}/bin/unzip -q -o ${k.zip} -d kext-${k.name}
+    K=$(find kext-${k.name} -type d -name "${k.name}.kext" | head -1)
+    [ -n "$K" ] || { echo "${k.name}.kext not found in ${k.zip.name}"; exit 1; }
+    rm -rf "$out/EFI/OC/Kexts/${k.name}.kext"
+    cp -r "$K" "$out/EFI/OC/Kexts/${k.name}.kext"
+    grep -A1 CFBundleVersion "$out/EFI/OC/Kexts/${k.name}.kext/Contents/Info.plist" | tail -1
+  '') kextZips}
   # hide OpenCore's own launcher from its picker (otherwise it is the default entry and loops)
   echo -n Disabled > $out/EFI/BOOT/.contentVisibility
   python3 ${./oc-config.py} --base esp/EFI/OC/config.plist --esp esp --out $out/EFI/OC/config.plist \
     --model "${model}" --serial "$SERIAL" --mlb "$MLB" --uuid "${uuid}" --mac "${mac}" \
     --nic-path "${qemu.nicDevicePath}" --boot-args "${bootArgs}" --resolution "${resolution}" \
     --show-picker "${lib.boolToString showPicker}" --timeout ${toString pickerTimeout} \
-    --extra-json ${lib.escapeShellArg (builtins.toJSON extraConfig)} --memory-mb ${toString memSize}
+    --extra-json ${lib.escapeShellArg (builtins.toJSON extraConfig)} --memory-mb ${toString memSize} --add-kexts ${lib.concatStringsSep "," (map (k: k.name) kextZips)}
   ocvalidate $out/EFI/OC/config.plist || echo "vmix: ocvalidate reported issues (OpenCore version may differ from validator), continuing"
 
   jq -n --arg model "${model}" --arg serial "$SERIAL" --arg mlb "$MLB" --arg uuid "${uuid}" --arg mac "${mac}" \

lib/images/macos/helpers/oc-config.py

@@ -44,6 +44,7 @@ def main():
     p.add_argument('--timeout', type=int, default=2)
     p.add_argument('--extra-json', default='{}')
     p.add_argument('--memory-mb', type=int, default=8192, help='VM RAM, described as 4 DIMMs')
+    p.add_argument('--add-kexts', default='', help='comma-separated kext names (without .kext) that need a Kernel.Add entry')
     a = p.parse_args()
 
     with open(a.base, 'rb') as f:
@@ -85,6 +86,18 @@ def main():
     cfg['Misc']['Boot']['Timeout'] = a.timeout
     cfg['Misc']['Boot']['HideAuxiliary'] = True
     cfg['Misc']['Security']['ScanPolicy'] = 0
+    # kexts overlaid into the ESP that the OSX-KVM config does not list yet
+    # (RestrictEvents: silences MacPro7,1's "Memory Modules Misconfigured", revpatch=memtab)
+    listed = {k['BundlePath'] for k in cfg['Kernel']['Add']}
+    for kext in [k + '.kext' for k in a.add_kexts.split(',') if k]:
+        if kext not in listed:
+            name = kext[:-5]
+            cfg['Kernel']['Add'].append({
+                'Arch': 'Any', 'BundlePath': kext, 'Comment': f'{name} (vmix)', 'Enabled': True,
+                'ExecutablePath': f'Contents/MacOS/{name}', 'MaxKernel': '', 'MinKernel': '',
+                'PlistPath': 'Contents/Info.plist'})
+            print('Kernel.Add +', kext)
+
     # MacPro7,1 firmware expects DIMMs in pairs (>= 4); with QEMU's single SMBIOS
     # module macOS shows "Memory Modules Misconfigured" at every login. Describe
     # the VM's RAM as four DDR4 modules instead.

lib/images/macos/helpers/qemu.nix

@@ -17,14 +17,20 @@ rec {
   netArgs = { mac, netdev ? "user,id=net0", extra ? "" }:
     "-netdev ${netdev} -device virtio-net-pci,netdev=net0,mac=${mac},bus=pcie.0,addr=${nicAddr}${extra}";
 
-  # Devices macOS needs (no accel, disks, display adapter or display server here)
-  deviceArgs = ''-device isa-applesmc,osk="${osk}" -smbios type=2 -device qemu-xhci,id=xhci -device usb-kbd,bus=xhci.0 -device usb-tablet,bus=xhci.0 -device usb-ehci,id=ehci -device ich9-intel-hda -device hda-duplex -device ich9-ahci,id=sata -global ICH9-LPC.disable_s3=1'';
+  # Devices macOS needs (no accel, disks, display adapter or display server here).
+  # No isa-applesmc: QEMU's stub only answers the OSK keys, and its presence makes
+  # VirtualSMC (which carries the OSK itself) step aside, leaving Apple's SMC
+  # driver on the stub — whose missing watchdog keys panic the restart path on
+  # macOS 26. VirtualSMC alone is the standard Hackintosh setup.
+  deviceArgsFor = { appleSmc ? false }:
+    ''${lib.optionalString appleSmc ''-device isa-applesmc,osk="${osk}" ''}-smbios type=2 -device qemu-xhci,id=xhci -device usb-kbd,bus=xhci.0 -device usb-tablet,bus=xhci.0 -device usb-ehci,id=ehci -device ich9-intel-hda -device hda-duplex -device ich9-ahci,id=sata -global ICH9-LPC.disable_s3=1'';
+  deviceArgs = deviceArgsFor { };
 
   # macOS has no QXL/virtio-gpu driver; VMware SVGA gives a plain framebuffer
   vgaArgs = "-vga vmware";
 
-  machineArgs = { cpu ? defaultCpu, smp ? 4, memSize ? 4096 }:
-    "-accel kvm -machine type=q35 -cpu ${cpu} -smp ${toString smp},sockets=1,cores=${toString smp},threads=1 -m ${toString memSize} ${deviceArgs} ${vgaArgs}";
+  machineArgs = { cpu ? defaultCpu, smp ? 4, memSize ? 4096, appleSmc ? false }:
+    "-accel kvm -machine type=q35 -cpu ${cpu} -smp ${toString smp},sockets=1,cores=${toString smp},threads=1 -m ${toString memSize} ${deviceArgsFor { inherit appleSmc; }} ${vgaArgs}";
 
   # SATA disk on a given port. Store files are read-only: callers create qcow2 overlays.
   sataDrive = { id, port, file, format ? "qcow2", extra ? "" }:

lib/images/macos/helpers/vm-driver.py

@@ -25,6 +25,7 @@ import shutil
 import socket
 import subprocess
 import sys
+import tempfile
 import time
 
 try:
@@ -188,17 +189,25 @@ class Serial:
 
 
 def prepare_debug_dir(path):
-    os.makedirs(path, exist_ok=True)
+    """Create the debug dir; builds run as different nixbld users, so the parent
+    is made world-writable and a temp dir is used if the path is not writable."""
+    parent = os.path.dirname(path)
     try:
+        if not os.path.isdir(parent):
+            os.makedirs(parent, exist_ok=True)
+            os.chmod(parent, 0o777)
+        os.makedirs(path, exist_ok=True)
         os.chmod(path, 0o777)
     except OSError:
-        pass
+        path = tempfile.mkdtemp(prefix=os.path.basename(path) + '-', dir='/tmp')
+        os.chmod(path, 0o777)
     for f in os.listdir(path):
         if f.endswith(('.png', '.ppm', '.log')) or f.startswith('.grab-') or f == 'qmp.sock':
             try:
                 os.remove(os.path.join(path, f))
             except OSError:
                 pass
+    return path
 
 
 def launch(qemu_args, qmp_sock, log):
@@ -270,9 +279,9 @@ def drive(args, proc, qmp, screen, serial, log):
                 log(f'kernel panic #{panics}, giving up')
                 proc.kill()
                 return 3
-            log(f'kernel panic #{panics}, system_reset')
-            qmp.system_reset()
-            screen.stable_since = time.time()
+            # XNU reboots by itself after a panic; only reset if no kernel comes back
+            log(f'kernel panic #{panics}, waiting for the guest to reboot')
+            serial.reboot_at = now
             continue
 
         # The guest asked for a reboot but no kernel came back: macOS' restart
@@ -351,7 +360,9 @@ def drive(args, proc, qmp, screen, serial, log):
                         log('QEMU exited after powerdown')
                         return 0
                     time.sleep(1)
-                log('guest ignored powerdown, killing QEMU')
+                # macOS ignores the power button at the Setup Assistant; the
+                # volumes are journaled (APFS) and the PE mounts them cleanly next
+                log('guest ignores the ACPI power button here (Setup Assistant); stopping QEMU')
                 proc.kill()
                 return 0
             continue
@@ -395,7 +406,7 @@ def main():
         p.error('QEMU command line required after --')
 
     debug_dir = args.debug_dir or f'/tmp/vmix-macos/{args.name}'
-    prepare_debug_dir(debug_dir)
+    debug_dir = prepare_debug_dir(debug_dir)
     log = Log(os.path.join(debug_dir, 'driver.log'))
     log(f'mode={args.mode} debug-dir={debug_dir} serial={args.serial_log}')