Fix raw USB live boot and verify both installation media paths

dev/iso-smoke.py

@@ -635,7 +635,12 @@ def qemu_path(path):
     return str(path)
 
 
-def qemu_argv(qemu, scratch, disk, code, variables, iso, memory, *, keep_cdrom_drive=False):
+def qemu_argv(qemu, scratch, disk, code, variables, iso, memory, *, keep_cdrom_drive=False,
+              live_media='cdrom'):
+    if live_media not in {'cdrom', 'usb'}:
+        raise SmokeError('Unknown live media; choose cdrom or usb')
+    if keep_cdrom_drive and live_media == 'usb':
+        raise SmokeError('keep_cdrom_drive cannot be combined with usb live media')
     scratch = Path(scratch)
     owned_file(disk, scratch)
     owned_file(variables, scratch)
@@ -658,10 +663,14 @@ def qemu_argv(qemu, scratch, disk, code, variables, iso, memory, *, keep_cdrom_d
         if iso is not None:
             optical += ',format=raw,file=' + qemu_path(iso)
         argv += ['-drive', optical]
+    elif iso is not None and live_media == 'usb':
+        argv += ['-drive', f'if=none,id=acceptance-usb,format=raw,readonly=on,file={qemu_path(iso)}',
+                 '-device', 'qemu-xhci,id=acceptance-xhci',
+                 '-device', 'usb-storage,bus=acceptance-xhci.0,drive=acceptance-usb,bootindex=1']
     elif iso is not None:
         argv += ['-drive', f'file={qemu_path(iso)},media=cdrom,format=raw,readonly=on']
     if iso is not None:
-        argv += ['-boot', 'order=d,strict=on']
+        argv += ['-boot', 'strict=on' if live_media == 'usb' else 'order=d,strict=on']
     else:
         argv += ['-boot', 'order=c,strict=on']
     return argv
@@ -827,7 +836,8 @@ class VM:
         self.stderr = open(scratch / f'{phase}-qemu.log', 'ab', buffering=0)
         self.process = subprocess.Popen(qemu_argv(args.qemu, scratch, disk,
             args.ovmf_code, scratch / 'OVMF_VARS.fd', iso, args.memory,
-            keep_cdrom_drive=getattr(args, 'keep_cdrom_drive', False)),
+            keep_cdrom_drive=getattr(args, 'keep_cdrom_drive', False),
+            live_media=getattr(args, 'live_media', 'cdrom')),
             stdin=subprocess.DEVNULL, stdout=self.stderr, stderr=self.stderr)
         self.console = None
         self.qmp = None
@@ -910,6 +920,25 @@ for tool in hydra hydra-install qemu-system-x86_64 qemu-img remote-viewer foot l
 for service in NetworkManager hydra-network hydra-dnsmasq; do systemctl is-active "$service"; done
 '''
 
+LIVE_GRAPHICAL_CHECK = r'''set -eu
+systemctl is-active greetd
+pgrep -u hydra-live -x labwc
+pgrep -u hydra-live -x foot
+'''
+
+
+def live_graphical_probe(console, timeout=30):
+    # Serial login can become ready before greetd has launched the live shell.
+    deadline = time.monotonic() + timeout
+    while True:
+        try:
+            return console.command(LIVE_GRAPHICAL_CHECK, min(10, max(0, deadline - time.monotonic())))
+        except SmokeError:
+            if time.monotonic() >= deadline:
+                raise
+            time.sleep(min(1, max(0, deadline - time.monotonic())))
+
+
 INSTALLED_CHECK = r'''set -eu
 assert_no_match() {
     if grep "$@"; then
@@ -1069,6 +1098,10 @@ def digest(path):
 def main(argv=None):
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument('--iso', required=True, type=Path)
+    parser.add_argument('--live-media', choices=('cdrom', 'usb'), default='cdrom',
+                        help='Attach ISO as optical media or a read-only raw USB disk')
+    parser.add_argument('--live-only', action='store_true',
+                        help='Check live boot and graphical session, then power off without installing')
     parser.add_argument('--ovmf-code', required=True, type=Path)
     parser.add_argument('--ovmf-vars', required=True, type=Path)
     parser.add_argument('--qemu', default='qemu-system-x86_64')
@@ -1092,6 +1125,7 @@ def main(argv=None):
     print(f'Acceptance artifacts: {scratch}', flush=True)
     report = {'schema': 1, 'status': 'running', 'scratch': str(scratch),
               'iso': str(args.iso), 'iso_sha256': digest(args.iso),
+              'live_media': args.live_media, 'scope': 'live-only' if args.live_only else 'install-reboot',
               'checks': {}, 'physical_hardware': 'pending',
               'nested_scope': 'Normal-user KVM VM launch, bridge helper and QMP; no nested guest OS boot',
               'ovmf_code_sha256': digest(args.ovmf_code),
@@ -1115,6 +1149,13 @@ def main(argv=None):
         console = vm.console
         console.expect(rb'hydra-live[^\r\n]*[#$] ', args.boot_timeout)
         checkpoint('live_boot', console.command(LIVE_CHECK, 90))
+        if args.live_only:
+            checkpoint('live_graphical_session', live_graphical_probe(console))
+            console.send('sudo -n poweroff\n')
+            vm.wait_poweroff(90)
+            checkpoint('live_poweroff', b'Live-only check completed without invoking the installer')
+            report['status'] = 'passed'
+            return 0
         console.buffer = b''
         installer_token = secrets.token_hex(12)
         console.send(installer_command(installer_token) + '\n')