qemu: /dev/kvm mode is now set in LFS, and logind-based access is allowed

general.ent

@@ -196,3 +196,7 @@ export -f as_root</userinput></screen>
 <!ENTITY test-use-internet
          "<note><para>An Internet connection is needed for some tests of
           this package.</para></note>">
+
+<!ENTITY logind
+         "<phrase revision='sysv'><xref linkend='elogind'/></phrase>
+          <phrase revision='systemd'><xref linkend='systemd'/></phrase>">

postlfs/virtualization/qemu.xml

@@ -104,6 +104,11 @@
       <ulink url="https://gitlab.freedesktop.org/spice/libcacard">libcacard</ulink>
     </para>
 
+    <bridgehead renderas="sect4">Optional (Runtime)</bridgehead>
+    <para role="runtime">
+      &logind;
+    </para>
+
     <bridgehead renderas="sect4">Optional (for building the documentation)</bridgehead>
     <para role="optional">
       <xref linkend="sphinx_rtd_theme"/>
@@ -190,8 +195,14 @@ Device Drivers  ---&gt;
 <screen role="root" revision="sysv"><userinput>groupadd -g 61 kvm</userinput></screen>
 -->
     <para>
-      As the &root; user, add any users that might use the KVM device to that
-      group:
+      The udev rule of LFS only allows the &root; user, the users owning
+      a local login session supported by the optional runtime dependency
+      &logind;, or the users in the
+      <systemitem class="groupname">kvm</systemitem> group to use the KVM
+      device.  As the &root; user, add any non-&root; users that might use
+      the KVM device either without &logind; installed or remotely (via a
+      SSH connection) to the
+      <systemitem class="groupname">kvm</systemitem> group:
     </para>
 
 <screen role="root"><userinput>usermod -a -G kvm <replaceable>&lt;username&gt;</replaceable></userinput></screen>