[Devel] [PATCH RHEL7 COMMIT] drivers/hyperv: Balloon report stats to mm core

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-1160.76.1.vz7.189.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-1160.76.1.vz7.189.4
------>
commit 51139834e3af42ea942601edfe48ad4e8fa2e894
Author: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
Date:   Wed Oct 5 13:25:31 2022 +0300

    drivers/hyperv: Balloon report stats to mm core
    
    Propagate balloon stats to mm core.
    
    Hyper-V balloon driver changes TOTAL RAM size reported by the guest,
    thus propagating the "InflatedTotal" counter to mm.
    
    https://jira.sw.ru/browse/PSBM-142436
    
    Signed-off-by: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
---
 drivers/hv/hv_balloon.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 9bf30659a975..df3e41cb340a 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -32,6 +32,7 @@
 #include <linux/memory.h>
 #include <linux/notifier.h>
 #include <linux/percpu_counter.h>
+#include <linux/balloon_compaction.h>
 
 #include <linux/hyperv.h>
 #include <asm/mshyperv.h>
@@ -1280,6 +1281,14 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
 	return num_pages;
 }
 
+static void report_ballooned_pages(struct hv_dynmem_device *dm)
+{
+	u32 actual = dm->num_pages_ballooned;
+	long inflated_kb = actual << (HV_HYP_PAGE_SHIFT - 10);
+
+	balloon_set_inflated_total(inflated_kb);
+}
+
 static void balloon_up(struct work_struct *dummy)
 {
 	unsigned int num_pages = dm_device.balloon_wrk.num_pages;
@@ -1372,6 +1381,7 @@ static void balloon_up(struct work_struct *dummy)
 		}
 	}
 
+	report_ballooned_pages(&dm_device);
 }
 
 static void balloon_down(struct hv_dynmem_device *dm,
@@ -1391,6 +1401,8 @@ static void balloon_down(struct hv_dynmem_device *dm,
 	pr_debug("Freed %u ballooned pages.\n",
 		prev_pages_ballooned - dm->num_pages_ballooned);
 
+	report_ballooned_pages(dm);
+
 	if (req->more_pages == 1)
 		return;