6 files changed, 28 insertions, 24 deletions

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 50dcb68..ab60925 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -780,6 +780,9 @@ 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/events/events_base.c b/drivers/xen/events/events_base.c
index b241bfa..bae1f5d3 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -343,14 +343,6 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 	info->cpu = cpu;
 }
 
-static void xen_evtchn_mask_all(void)
-{
-	unsigned int evtchn;
-
-	for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
-		mask_evtchn(evtchn);
-}
-
 /**
  * notify_remote_via_irq - send event to remote end of event channel via irq
  * @irq: irq of event channel to send event to
@@ -1573,7 +1565,6 @@ void xen_irq_resume(void)
 	struct irq_info *info;
 
 	/* New event-channel space is not 'live' yet. */
-	xen_evtchn_mask_all();
 	xen_evtchn_resume();
 
 	/* No IRQ <-> event-channel mappings. */
@@ -1681,6 +1672,7 @@ module_param(fifo_events, bool, 0);
 void __init xen_init_IRQ(void)
 {
 	int ret = -EINVAL;
+	unsigned int evtchn;
 
 	if (fifo_events)
 		ret = xen_evtchn_fifo_init();
@@ -1692,7 +1684,8 @@ void __init xen_init_IRQ(void)
 	BUG_ON(!evtchn_to_irq);
 
 	/* No event channels are 'live' right now. */
-	xen_evtchn_mask_all();
+	for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
+		mask_evtchn(evtchn);
 
 	pirq_needs_eoi = pirq_needs_eoi_flag;
 
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index d6786b8..2c6a911 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -42,6 +42,7 @@
 #include <linux/delay.h>
 #include <linux/hardirq.h>
 #include <linux/workqueue.h>
+#include <linux/ratelimit.h>
 
 #include <xen/xen.h>
 #include <xen/interface/xen.h>
@@ -1072,8 +1073,14 @@ static int gnttab_expand(unsigned int req_entries)
 	cur = nr_grant_frames;
 	extra = ((req_entries + (grefs_per_grant_frame-1)) /
 		 grefs_per_grant_frame);
-	if (cur + extra > gnttab_max_grant_frames())
+	if (cur + extra > gnttab_max_grant_frames()) {
+		pr_warn_ratelimited("xen/grant-table: max_grant_frames reached"
+				    " cur=%u extra=%u limit=%u"
+				    " gnttab_free_count=%u req_entries=%u\n",
+				    cur, extra, gnttab_max_grant_frames(),
+				    gnttab_free_count, req_entries);
 		return -ENOSPC;
+	}
 
 	rc = gnttab_map(cur, cur + extra - 1);
 	if (rc == 0)
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index e7715cb..e89136a 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -59,6 +59,8 @@ 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) {
@@ -69,7 +71,14 @@ 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.
 	 */
-	balloon_set_new_target(new_target >> (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;
 }
 static struct xenbus_watch target_watch = {
 	.node = "memory/target",
@@ -94,22 +103,15 @@ static struct notifier_block xenstore_notifier = {
 	.notifier_call = balloon_init_watcher,
 };
 
-static int __init balloon_init(void)
+void xen_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;
 }
-subsys_initcall(balloon_init);
+EXPORT_SYMBOL_GPL(xen_balloon_init);
 
 #define BALLOON_SHOW(name, format, args...)				\
 	static ssize_t show_##name(struct device *dev,			\
diff --git a/drivers/xen/xen-selfballoon.c b/drivers/xen/xen-selfballoon.c
index 6662071..a67e955 100644
--- a/drivers/xen/xen-selfballoon.c
+++ b/drivers/xen/xen-selfballoon.c
@@ -151,8 +151,8 @@ static unsigned long frontswap_inertia_counter;
 static void frontswap_selfshrink(void)
 {
 	static unsigned long cur_frontswap_pages;
-	static unsigned long last_frontswap_pages;
-	static unsigned long tgt_frontswap_pages;
+	unsigned long last_frontswap_pages;
+	unsigned long tgt_frontswap_pages;
 
 	last_frontswap_pages = cur_frontswap_pages;
 	cur_frontswap_pages = frontswap_curr_pages();
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index 967f069..71ddfb4 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -87,7 +87,6 @@ static int __init xenfs_init(void)
 	if (xen_domain())
 		return register_filesystem(&xenfs_type);
 
-	pr_info("not registering filesystem on non-xen platform\n");
 	return 0;
 }