From 8390e2846683049dfb3df6d25195c866f8fd173c Mon Sep 17 00:00:00 2001
From: HW42 <hw42@ipsumj.de>
Date: Mon, 2 Oct 2017 22:29:35 +0200
Subject: [PATCH] Revert patch which breaks memory ballooning for HVM/PVH

---
 ...on-don-t-online-new-memory-initially.patch | 99 +++++++++++++++++++
 series.conf                                   |  2 +
 2 files changed, 101 insertions(+)
 create mode 100644 patches.xen/Revert-xen-balloon-don-t-online-new-memory-initially.patch

diff --git a/patches.xen/Revert-xen-balloon-don-t-online-new-memory-initially.patch b/patches.xen/Revert-xen-balloon-don-t-online-new-memory-initially.patch
new file mode 100644
index 0000000..6ef698f
--- /dev/null
+++ b/patches.xen/Revert-xen-balloon-don-t-online-new-memory-initially.patch
@@ -0,0 +1,99 @@
+From ae10fc424982b3c841c77dc9b1fa3ec96d8f5851 Mon Sep 17 00:00:00 2001
+From: HW42 <hw42@ipsumj.de>
+Date: Fri, 29 Sep 2017 17:59:14 +0200
+Subject: [PATCH] Revert "xen/balloon: don't online new memory initially"
+
+This reverts commit 96edd61dcf44362d3ef0bed1a5361e0ac7886a63.
+---
+ drivers/xen/balloon.c     |  3 ---
+ drivers/xen/xen-balloon.c | 22 ++++++++++------------
+ include/xen/balloon.h     |  8 --------
+ 3 files changed, 10 insertions(+), 23 deletions(-)
+
+diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
+index ab609255a0f3..50dcb68d8070 100644
+--- a/drivers/xen/balloon.c
++++ b/drivers/xen/balloon.c
+@@ -780,9 +780,6 @@ static int __init balloon_init(void)
+ 	}
+ #endif
+ 
+-	/* Init the xen-balloon driver. */
+-	xen_balloon_init();
+-
+ 	return 0;
+ }
+ subsys_initcall(balloon_init);
+diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
+index e89136ab851e..e7715cb62eef 100644
+--- a/drivers/xen/xen-balloon.c
++++ b/drivers/xen/xen-balloon.c
+@@ -59,8 +59,6 @@ static void watch_target(struct xenbus_watch *watch,
+ {
+ 	unsigned long long new_target;
+ 	int err;
+-	static bool watch_fired;
+-	static long target_diff;
+ 
+ 	err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target);
+ 	if (err != 1) {
+@@ -71,14 +69,7 @@ static void watch_target(struct xenbus_watch *watch,
+ 	/* The given memory/target value is in KiB, so it needs converting to
+ 	 * pages. PAGE_SHIFT converts bytes to pages, hence PAGE_SHIFT - 10.
+ 	 */
+-	new_target >>= PAGE_SHIFT - 10;
+-	if (watch_fired) {
+-		balloon_set_new_target(new_target - target_diff);
+-		return;
+-	}
+-
+-	watch_fired = true;
+-	target_diff = new_target - balloon_stats.target_pages;
++	balloon_set_new_target(new_target >> (PAGE_SHIFT - 10));
+ }
+ static struct xenbus_watch target_watch = {
+ 	.node = "memory/target",
+@@ -103,15 +94,22 @@ static struct notifier_block xenstore_notifier = {
+ 	.notifier_call = balloon_init_watcher,
+ };
+ 
+-void xen_balloon_init(void)
++static int __init balloon_init(void)
+ {
++	if (!xen_domain())
++		return -ENODEV;
++
++	pr_info("Initialising balloon driver\n");
++
+ 	register_balloon(&balloon_dev);
+ 
+ 	register_xen_selfballooning(&balloon_dev);
+ 
+ 	register_xenstore_notifier(&xenstore_notifier);
++
++	return 0;
+ }
+-EXPORT_SYMBOL_GPL(xen_balloon_init);
++subsys_initcall(balloon_init);
+ 
+ #define BALLOON_SHOW(name, format, args...)				\
+ 	static ssize_t show_##name(struct device *dev,			\
+diff --git a/include/xen/balloon.h b/include/xen/balloon.h
+index 8906361bb50c..d1767dfb0d95 100644
+--- a/include/xen/balloon.h
++++ b/include/xen/balloon.h
+@@ -35,11 +35,3 @@ static inline int register_xen_selfballooning(struct device *dev)
+ 	return -ENOSYS;
+ }
+ #endif
+-
+-#ifdef CONFIG_XEN_BALLOON
+-void xen_balloon_init(void);
+-#else
+-static inline void xen_balloon_init(void)
+-{
+-}
+-#endif
+-- 
+2.14.2
+
diff --git a/series.conf b/series.conf
index 0950b46..74d8e79 100644
--- a/series.conf
+++ b/series.conf
@@ -22,3 +22,5 @@ patches.xen/xsa155-linux44-0013-xen-blkfront-prepare-request-locally-only-then-p
 
 # MSI-X enabled device passthrough fix (#1734)
 patches.xen/pci_op-cleanup.patch
+
+patches.xen/Revert-xen-balloon-don-t-online-new-memory-initially.patch