1 files changed, 15 insertions, 8 deletions

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 73708acce3ca..979a8317204f 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -37,23 +37,30 @@ config XEN_BALLOON_MEMORY_HOTPLUG
 
           Memory could be hotplugged in following steps:
 
-            1) dom0: xl mem-max <domU> <maxmem>
+            1) target domain: ensure that memory auto online policy is in
+               effect by checking /sys/devices/system/memory/auto_online_blocks
+               file (should be 'online').
+
+            2) control domain: xl mem-max <target-domain> <maxmem>
                where <maxmem> is >= requested memory size,
 
-            2) dom0: xl mem-set <domU> <memory>
+            3) control domain: xl mem-set <target-domain> <memory>
                where <memory> is requested memory size; alternatively memory
                could be added by writing proper value to
                /sys/devices/system/xen_memory/xen_memory0/target or
-               /sys/devices/system/xen_memory/xen_memory0/target_kb on dumU,
+               /sys/devices/system/xen_memory/xen_memory0/target_kb on the
+               target domain.
 
-            3) domU: for i in /sys/devices/system/memory/memory*/state; do \
-                       [ "`cat "$i"`" = offline ] && echo online > "$i"; done
+          Alternatively, if memory auto onlining was not requested at step 1
+          the newly added memory can be manually onlined in the target domain
+          by doing the following:
 
-          Memory could be onlined automatically on domU by adding following line to udev rules:
+                for i in /sys/devices/system/memory/memory*/state; do \
+                  [ "`cat "$i"`" = offline ] && echo online > "$i"; done
 
-          SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
+          or by adding the following line to udev rules:
 
-          In that case step 3 should be omitted.
+          SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
 
 config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
         int "Hotplugged memory limit (in GiB) for a PV guest"