added machine_id_smbios variable

FML128 · Apr 3, 2024 · c3882d8 · c3882d8
1 parent c099e8f
commit c3882d8
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Showing 3 changed files with 18 additions and 2 deletions.
diff --git a/man/kernel-command-line.xml b/man/kernel-command-line.xml
@@ -68,6 +68,7 @@
         <term><varname>systemd.default_standard_error=</varname></term>
         <term><varname>systemd.setenv=</varname></term>
         <term><varname>systemd.machine_id=</varname></term>
+        <term><varname>systemd.machine_id_smbios</varname></term>
         <term><varname>systemd.set_credential=</varname></term>
         <term><varname>systemd.set_credential_binary=</varname></term>
         <term><varname>systemd.import_credentials=</varname></term>

diff --git a/man/machine-id.xml b/man/machine-id.xml
@@ -104,6 +104,8 @@
     (on KVM systems), the Xen hypervisor <filename>uuid</filename>, and finally a randomly
     generated UUID.</para>
 
+    <para>The vm logic can be enabled manually by setting the <varname>systemd.machine_id_smbios</varname> kernel command line option.</para>
+
     <para>After the machine ID is established,
     <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
     will attempt to save it to <filename>/etc/machine-id</filename>. If this fails, it

diff --git a/src/shared/machine-id-setup.c b/src/shared/machine-id-setup.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include <fcntl.h>
+#include <proc-cmdline.h>
 #include <sched.h>
 #include <sys/mount.h>
 #include <unistd.h>
@@ -48,6 +49,18 @@ static int acquire_machine_id_from_credential(sd_id128_t *ret) {
         return 0;
 }
 
+static bool machine_id_smbios(void) {
+        bool b = false;
+        int r;
+
+        r = proc_cmdline_get_bool("systemd.machine_id_smbios", PROC_CMDLINE_VALUE_OPTIONAL, &b);
+        if (r < 0) {
+                log_warning_errno(r, "Failed to read systemd.machine_id_smbios from kernel command line, ignoring: %m");
+                return false;
+        }
+        return b;
+}
+
 static int generate_machine_id(const char *root, sd_id128_t *ret) {
         _cleanup_close_ int fd = -EBADF;
         int r;
@@ -80,14 +93,14 @@ static int generate_machine_id(const char *root, sd_id128_t *ret) {
                                 return 0;
                         }
 
-                } else if (IN_SET(detect_vm(), VIRTUALIZATION_KVM, VIRTUALIZATION_AMAZON, VIRTUALIZATION_QEMU, VIRTUALIZATION_XEN)) {
+                } else if (IN_SET(detect_vm(), VIRTUALIZATION_KVM, VIRTUALIZATION_AMAZON, VIRTUALIZATION_QEMU, VIRTUALIZATION_XEN) || machine_id_smbios()) {
 
                         /* If we are not running in a container, see if we are running in a VM that provides
                          * a system UUID via the SMBIOS/DMI interfaces.  Such environments include QEMU/KVM
                          * with the -uuid on the qemu command line or the Amazon EC2 Nitro hypervisor. */
 
                         if (id128_get_product(ret) >= 0) {
-                                log_info("Initializing machine ID from VM UUID.");
+                                log_info("Initializing machine ID from SMBIOS/DMI UUID.");
                                 return 0;
                         }
                 }