virsh: Fix semantics of --config for "update-device" command

The man page states that with --config the next boot is affected. This
can be understood as if _only_ the next boot was affected. This isn't
true if the machine is running.

This patch adds the full --live, --config, --current infrastructure and
tweaks stuff to correctly support the obsolete --persistent flag.

Note that this patch changes the the behavior of the --config flag to match the
use of this flag in rest of libvirt. This flag was mistakenly renamed from
--persistent that originaly had different semantics.

tools/virsh-domain.c

@@ -9180,13 +9180,21 @@ static const vshCmdOptDef opts_update_device[] = {
      .help = N_("XML file")
     },
     {.name = "persistent",
-     .type = VSH_OT_ALIAS,
-     .help = "config"
+     .type = VSH_OT_BOOL,
+     .help = N_("make live change persistent")
     },
     {.name = "config",
      .type = VSH_OT_BOOL,
      .help = N_("affect next boot")
     },
+    {.name = "live",
+     .type = VSH_OT_BOOL,
+     .help = N_("affect running domain")
+    },
+    {.name = "current",
+     .type = VSH_OT_BOOL,
+     .help = N_("affect current domain")
+    },
     {.name = "force",
      .type = VSH_OT_BOOL,
      .help = N_("force device update")
@@ -9201,7 +9209,21 @@ cmdUpdateDevice(vshControl *ctl, const vshCmd *cmd)
     const char *from = NULL;
     char *buffer = NULL;
     bool ret = false;
-    unsigned int flags;
+    unsigned int flags = VIR_DOMAIN_AFFECT_CURRENT;
+    bool current = vshCommandOptBool(cmd, "current");
+    bool config = vshCommandOptBool(cmd, "config");
+    bool live = vshCommandOptBool(cmd, "live");
+    bool persistent = vshCommandOptBool(cmd, "persistent");
+
+    VSH_EXCLUSIVE_OPTIONS_VAR(persistent, current);
+
+    VSH_EXCLUSIVE_OPTIONS_VAR(current, live);
+    VSH_EXCLUSIVE_OPTIONS_VAR(current, config);
+
+    if (config || persistent)
+        flags |= VIR_DOMAIN_AFFECT_CONFIG;
+    if (live)
+        flags |= VIR_DOMAIN_AFFECT_LIVE;
 
     if (!(dom = vshCommandOptDomain(ctl, cmd, NULL)))
         return false;
@@ -9209,19 +9231,15 @@ cmdUpdateDevice(vshControl *ctl, const vshCmd *cmd)
     if (vshCommandOptStringReq(ctl, cmd, "file", &from) < 0)
         goto cleanup;
 
+    if (persistent &&
+        virDomainIsActive(dom) == 1)
+        flags |= VIR_DOMAIN_AFFECT_LIVE;
+
     if (virFileReadAll(from, VSH_MAX_XML_FILE, &buffer) < 0) {
         vshReportError(ctl);
         goto cleanup;
     }
 
-    if (vshCommandOptBool(cmd, "config")) {
-        flags = VIR_DOMAIN_AFFECT_CONFIG;
-        if (virDomainIsActive(dom) == 1)
-           flags |= VIR_DOMAIN_AFFECT_LIVE;
-    } else {
-        flags = VIR_DOMAIN_AFFECT_LIVE;
-    }
-
     if (vshCommandOptBool(cmd, "force"))
         flags |= VIR_DOMAIN_DEVICE_MODIFY_FORCE;
 

tools/virsh.pod

@@ -1888,18 +1888,28 @@ If I<--config> is specified, alter persistent configuration, effect observed
 on next boot, for compatibility purposes, I<--persistent> is alias of
 I<--config>.
 
-=item B<update-device> I<domain> I<file> [I<--config>] [I<--force>]
+=item B<update-device> I<domain> I<file> [I<--force>]
+[[[I<--live>] [I<--config>] | [I<--current>]] | [I<--persistent>]]
 
 Update the characteristics of a device associated with I<domain>,
-based on the device definition in an XML I<file>.  If the I<--config>
-option is used, the changes will take affect the next time libvirt
-starts the domain.  For compatibility purposes, I<--persistent> is
-alias of I<--config>.  The I<--force> option can be used to force
-device update, e.g., to eject a CD-ROM even if it is locked/mounted in
-the domain. See the documentation at
+based on the device definition in an XML I<file>.  The I<--force> option
+can be used to force device update, e.g., to eject a CD-ROM even if it is
+locked/mounted in the domain. See the documentation at
 L<http://libvirt.org/formatdomain.html#elementsDevices> to learn about
 libvirt XML format for a device.
 
+If I<--live> is specified, affect a running domain.
+If I<--config> is specified, affect the next startup of a persistent domain.
+If I<--current> is specified, affect the current domain state.
+Both I<--live> and I<--config> flags may be given, but I<--current> is
+exclusive. Not specifying any flag is the same as specifying I<--current>.
+
+For compatibility purposes, I<--persistent> behaves like I<--config> for
+an offline domain, and like I<--live> I<--config> for a running domain.
+
+Note that older versions of virsh used I<--config> as an alias for
+I<--persistent>.
+
 =item B<change-media> I<domain> I<path> [I<--eject>] [I<--insert>]
 [I<--update>] [I<source>] [I<--force>] [[I<--live>] [I<--config>] | [I<--current>]]