virsh: man: Document quirks of device-detach and friends

Mention that successful return does not equal to device being detached
similarly as we do at the API level.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

tools/virsh.pod

@@ -3264,6 +3264,16 @@ or attempting to detach a device that is not present in the domain XML,
 but shares some specific attributes with one that is present,
 may lead to unexpected results.
 
+B<Quirk>: Device unplug is asynchronous in most cases and requires guest
+cooperation. This means that it's up to the discretion of the guest to disallow
+or delay the unplug arbitrarily. As the libvirt API used in this command was
+designed as synchronous it returns success after some timeout even if the device
+was not unplugged yet to allow further interactions with the domain e.g. if the
+guest is unresponsive. Callers which need to make sure that the
+device was unplugged can use libvirt events (see virsh event) to be notified
+when the device is removed. Note that the event may arrive before the command
+returns.
+
 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.
@@ -3311,6 +3321,8 @@ I<--persistent>.
 If B<--print-xml> is specified, then the XML which would be used to detach the
 disk is printed instead.
 
+Please see documentation for B<detach-device> for known quirks.
+
 =item B<detach-interface> I<domain> I<type> [I<--mac mac>]
 [[[I<--live>] [I<--config>] | [I<--current>]] | [I<--persistent>]]
 
@@ -3333,6 +3345,8 @@ 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>.
 
+Please see documentation for B<detach-device> for known quirks.
+
 =item B<update-device> I<domain> I<file> [I<--force>]
 [[[I<--live>] [I<--config>] | [I<--current>]] | [I<--persistent>]]