1 files changed, 24 insertions, 9 deletions

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index ea3d33cdf99c..53932b3e1973 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -503,6 +503,8 @@ struct hv_dynmem_device {
          * Number of pages we have currently ballooned out.
          */
         unsigned int num_pages_ballooned;
+        unsigned int num_pages_onlined;
+        unsigned int num_pages_added;
 
         /*
          * State to manage the ballooning (up) operation.
@@ -556,12 +558,15 @@ static void post_status(struct hv_dynmem_device *dm);
 static int hv_memory_notifier(struct notifier_block *nb, unsigned long val,
                               void *v)
 {
+        struct memory_notify *mem = (struct memory_notify *)v;
+
         switch (val) {
         case MEM_GOING_ONLINE:
                 mutex_lock(&dm_device.ha_region_mutex);
                 break;
 
         case MEM_ONLINE:
+                dm_device.num_pages_onlined += mem->nr_pages;
         case MEM_CANCEL_ONLINE:
                 mutex_unlock(&dm_device.ha_region_mutex);
                 if (dm_device.ha_waiting) {
@@ -570,8 +575,12 @@ static int hv_memory_notifier(struct notifier_block *nb, unsigned long val,
                 }
                 break;
 
-        case MEM_GOING_OFFLINE:
         case MEM_OFFLINE:
+                mutex_lock(&dm_device.ha_region_mutex);
+                dm_device.num_pages_onlined -= mem->nr_pages;
+                mutex_unlock(&dm_device.ha_region_mutex);
+                break;
+        case MEM_GOING_OFFLINE:
         case MEM_CANCEL_OFFLINE:
                 break;
         }
@@ -896,6 +905,8 @@ static void hot_add_req(struct work_struct *dummy)
         if (do_hot_add)
                 resp.page_count = process_hot_add(pg_start, pfn_cnt,
                                                 rg_start, rg_sz);
+
+        dm->num_pages_added += resp.page_count;
         mutex_unlock(&dm_device.ha_region_mutex);
 #endif
         /*
@@ -1009,17 +1020,21 @@ static void post_status(struct hv_dynmem_device *dm)
         status.hdr.trans_id = atomic_inc_return(&trans_id);
 
         /*
-         * The host expects the guest to report free memory.
-         * Further, the host expects the pressure information to
-         * include the ballooned out pages.
-         * For a given amount of memory that we are managing, we
-         * need to compute a floor below which we should not balloon.
-         * Compute this and add it to the pressure report.
+         * The host expects the guest to report free and committed memory.
+         * Furthermore, the host expects the pressure information to include
+         * the ballooned out pages. For a given amount of memory that we are
+         * managing we need to compute a floor below which we should not
+         * balloon. Compute this and add it to the pressure report.
+         * We also need to report all offline pages (num_pages_added -
+         * num_pages_onlined) as committed to the host, otherwise it can try
+         * asking us to balloon them out.
          */
         status.num_avail = val.freeram;
         status.num_committed = vm_memory_committed() +
-                                dm->num_pages_ballooned +
-                                compute_balloon_floor();
+                dm->num_pages_ballooned +
+                (dm->num_pages_added > dm->num_pages_onlined ?
+                 dm->num_pages_added - dm->num_pages_onlined : 0) +
+                compute_balloon_floor();
 
         /*
          * If our transaction ID is no longer current, just don't