From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Wed, 31 May 2023 13:51:09 +0000 (+0200)
Subject: Add QemuSwtpm option
X-Git-Tag: v15~137
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09dd508290fcfaad42775f1c15de210d4befa593;p=thirdparty%2Fmkosi.git

Add QemuSwtpm option
---

diff --git a/mkosi.md b/mkosi.md
index de4048dbb..c3daae112 100644
--- a/mkosi.md
+++ b/mkosi.md
@@ -1018,6 +1018,12 @@ a boolean argument: either "1", "yes", or "true" to enable, or "0",
 : When used with the `qemu` verb, this option specifies whether QEMU should be configured with a vsock. Takes
   a boolean value or `auto`. Defaults to `auto`.
 
+`QemuSwtpm=`, `--qemu-swtpm=`
+
+: When used with the `qemu` verb, this option specified whether to start an instance of swtpm to be used as a
+  TPM with qemu. This requires swtpm to be installed on the host. Takes a boolean value or `auto`. Defaults
+  to `auto`.
+
 `QemuArgs=`
 
 : Space-delimited list of additional arguments to pass when invoking
diff --git a/mkosi/config.py b/mkosi/config.py
index 75cd4e3a0..391513713 100644
--- a/mkosi/config.py
+++ b/mkosi/config.py
@@ -670,6 +670,7 @@ class MkosiConfig:
     qemu_mem: str
     qemu_kvm: ConfigFeature
     qemu_vsock: ConfigFeature
+    qemu_swtpm: ConfigFeature
     qemu_args: Sequence[str]
 
     passphrase: Optional[Path]
@@ -1191,6 +1192,11 @@ class MkosiConfigParser:
             section="Host",
             parse=config_parse_feature,
         ),
+        MkosiConfigSetting(
+            dest="qemu_swtpm",
+            section="Host",
+            parse=config_parse_feature,
+        ),
         MkosiConfigSetting(
             dest="qemu_args",
             section="Host",
@@ -1910,6 +1916,13 @@ class MkosiConfigParser:
             nargs="?",
             action=action,
         )
+        group.add_argument(
+            "--qemu-swtpm",
+            metavar="FEATURE",
+            help="Configure whether to use qemu with swtpm or not",
+            nargs="?",
+            action=action,
+        )
         group.add_argument(
             "--qemu-args",
             metavar="ARGS",
@@ -2245,6 +2258,9 @@ def load_config(args: argparse.Namespace) -> MkosiConfig:
     if args.qemu_vsock == ConfigFeature.enabled and not qemu_check_vsock_support(log=False):
         die("Sorry, the host machine does not support vsock")
 
+    if args.qemu_swtpm == ConfigFeature.enabled and not shutil.which("swtpm"):
+        die("swtpm is requested but not found in PATH")
+
     if args.repositories and not (is_dnf_distribution(args.distribution) or is_apt_distribution(args.distribution)):
         die("Sorry, the --repositories option is only supported on DNF/Debian based distributions")
 
diff --git a/mkosi/qemu.py b/mkosi/qemu.py
index d8bb4aa61..d7167d632 100644
--- a/mkosi/qemu.py
+++ b/mkosi/qemu.py
@@ -135,27 +135,15 @@ def find_ovmf_vars(config: MkosiConfig) -> Path:
 
 @contextlib.contextmanager
 def start_swtpm() -> Iterator[Optional[Path]]:
-
-    if not shutil.which("swtpm"):
-        yield None
-        return
-
-    with tempfile.TemporaryDirectory() as swtpm_state:
-        swtpm_sock = Path(swtpm_state) / Path("sock")
-
-        cmd = ["swtpm",
-               "socket",
-               "--tpm2",
-               "--tpmstate", f"dir={swtpm_state}",
-               "--ctrl", f"type=unixio,path={swtpm_sock}",
-         ]
-
-        swtpm_proc = spawn(cmd)
+    with tempfile.TemporaryDirectory() as state:
+        sock = Path(state) / Path("sock")
+        proc = spawn(["swtpm", "socket", "--tpm2", "--tpmstate", f"dir={state}", "--ctrl", f"type=unixio,path={sock}"])
 
         try:
-            yield swtpm_sock
+            yield sock
         finally:
-            swtpm_proc.wait()
+            proc.terminate()
+            proc.wait()
 
 
 @contextlib.contextmanager
@@ -288,9 +276,9 @@ def run_qemu(args: MkosiArgs, config: MkosiConfig) -> None:
                         "-device", "virtio-scsi-pci,id=scsi",
                         "-device", "scsi-hd,drive=hd,bootindex=1"]
 
-        swtpm_socket = stack.enter_context(start_swtpm())
-        if swtpm_socket is not None:
-            cmdline += ["-chardev", f"socket,id=chrtpm,path={swtpm_socket}",
+        if config.qemu_swtpm != ConfigFeature.disabled and shutil.which("swtpm") is not None:
+            sock = stack.enter_context(start_swtpm())
+            cmdline += ["-chardev", f"socket,id=chrtpm,path={sock}",
                         "-tpmdev", "emulator,id=tpm0,chardev=chrtpm"]
 
             if config.architecture == Architecture.x86_64: