Document new vsock literals

Fixes #31849

4 files changed, 16 insertions, 9 deletions

diff --git a/docs/CREDENTIALS.md b/docs/CREDENTIALS.md
index ed30eacf2b..9c245dbf2b 100644
--- a/docs/CREDENTIALS.md
+++ b/docs/CREDENTIALS.md
@@ -380,7 +380,8 @@ Various services shipped with `systemd` consume credentials for tweaking behavio
   to receive a notification via VSOCK when a virtual machine has finished booting.
   Note that in case the hypervisor does not support `SOCK_DGRAM` over `AF_VSOCK`,
   `SOCK_SEQPACKET` will be tried instead. The credential payload should be in the
-  form: `vsock:<CID>:<PORT>`. Also note that this requires support for VHOST to be
+  form: `vsock:<CID>:<PORT>`. `vsock` may be replaced with `vsock-stream`, `vsock-dgram` or `vsock-seqpacket`
+  to force usage of the corresponding socket type. Also note that this requires support for VHOST to be
   built-in both the guest and the host kernels, and the kernel modules to be loaded.
 
 * [`systemd-sysusers(8)`](https://www.freedesktop.org/software/systemd/man/systemd-sysusers.html)
diff --git a/man/sd_notify.xml b/man/sd_notify.xml
index d8fe6468a2..1e611fe6d8 100644
--- a/man/sd_notify.xml
+++ b/man/sd_notify.xml
@@ -485,12 +485,14 @@
     <constant>AF_VSOCK</constant> address, which is useful for hypervisors/VMMs or other processes on the
     host to receive a notification when a virtual machine has finished booting. Note that in case the
     hypervisor does not support <constant>SOCK_DGRAM</constant> over <constant>AF_VSOCK</constant>,
-    <constant>SOCK_SEQPACKET</constant> will be used instead. The address should be in the form:
-    <literal>vsock:CID:PORT</literal>. Note that unlike other uses of vsock, the CID is mandatory and cannot
-    be <literal>VMADDR_CID_ANY</literal>.  Note that PID1 will send the VSOCK packets from a privileged port
-    (i.e.: lower than 1024), as an attempt to address concerns that unprivileged processes in the guest might
-    try to send malicious notifications to the host, driving it to make destructive decisions based on
-    them.</para>
+    <constant>SOCK_SEQPACKET</constant> will be used instead. <literal>vsock-stream</literal>,
+    <literal>vsock-dgram</literal> and <literal>vsock-seqpacket</literal> can be used instead of
+    <literal>vsock</literal> to force usage of the corresponding socket type. The address should be in the
+    form: <literal>vsock:CID:PORT</literal>. Note that unlike other uses of vsock, the CID is mandatory and
+    cannot be <literal>VMADDR_CID_ANY</literal>.  Note that PID1 will send the VSOCK packets from a
+    privileged port (i.e.: lower than 1024), as an attempt to address concerns that unprivileged processes in
+    the guest might try to send malicious notifications to the host, driving it to make destructive decisions
+    based on them.</para>
   </refsect1>
 
   <refsect1>
diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml
index 1ac97ae137..c7166e4f64 100644
--- a/man/systemd.socket.xml
+++ b/man/systemd.socket.xml
@@ -221,7 +221,9 @@
         <replaceable>x</replaceable> on a port <replaceable>y</replaceable> address in the
         <constant>AF_VSOCK</constant> family.  The CID is a unique 32-bit integer identifier in
         <constant>AF_VSOCK</constant> analogous to an IP address.  Specifying the CID is optional, and may be
-        set to the empty string.</para>
+        set to the empty string. <literal>vsock</literal> may be replaced with
+        <literal>vsock-stream</literal>, <literal>vsock-dgram</literal> or <literal>vsock-seqpacket</literal>
+        to force usage of the corresponding socket type.</para>
 
         <para>Note that <constant>SOCK_SEQPACKET</constant> (i.e.
         <varname>ListenSequentialPacket=</varname>) is only available
diff --git a/man/systemd.xml b/man/systemd.xml
index b66707faba..cb798af34c 100644
--- a/man/systemd.xml
+++ b/man/systemd.xml
@@ -1167,7 +1167,9 @@
           <constant>SOCK_DGRAM</constant> over <constant>AF_VSOCK</constant>,
           <constant>SOCK_SEQPACKET</constant> will be tried instead. The credential payload for
           <constant>AF_VSOCK</constant> should be a string in the form
-          <literal>vsock:CID:PORT</literal>.</para>
+          <literal>vsock:CID:PORT</literal>. <literal>vsock-stream</literal>, <literal>vsock-dgram</literal>
+          and <literal>vsock-seqpacket</literal> can be used instead of <literal>vsock</literal> to force
+          usage of the corresponding socket type.</para>
 
           <para>This feature is useful for machine managers or other processes on the host to receive a
           notification via VSOCK when a virtual machine has finished booting.</para>