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path: root/drivers/hv/hv_balloon.c
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Diffstat (limited to 'drivers/hv/hv_balloon.c')
-rw-r--r--drivers/hv/hv_balloon.c131
1 files changed, 94 insertions, 37 deletions
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 4ae26d60565f..18766f616b8d 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -441,6 +441,16 @@ struct hv_hotadd_state {
unsigned long covered_end_pfn;
unsigned long ha_end_pfn;
unsigned long end_pfn;
+ /*
+ * A list of gaps.
+ */
+ struct list_head gap_list;
+};
+
+struct hv_hotadd_gap {
+ struct list_head list;
+ unsigned long start_pfn;
+ unsigned long end_pfn;
};
struct balloon_state {
@@ -596,18 +606,46 @@ static struct notifier_block hv_memory_nb = {
.priority = 0
};
+/* Check if the particular page is backed and can be onlined and online it. */
+static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg)
+{
+ unsigned long cur_start_pgp;
+ unsigned long cur_end_pgp;
+ struct hv_hotadd_gap *gap;
+
+ cur_start_pgp = (unsigned long)pfn_to_page(has->covered_start_pfn);
+ cur_end_pgp = (unsigned long)pfn_to_page(has->covered_end_pfn);
-static void hv_bring_pgs_online(unsigned long start_pfn, unsigned long size)
+ /* The page is not backed. */
+ if (((unsigned long)pg < cur_start_pgp) ||
+ ((unsigned long)pg >= cur_end_pgp))
+ return;
+
+ /* Check for gaps. */
+ list_for_each_entry(gap, &has->gap_list, list) {
+ cur_start_pgp = (unsigned long)
+ pfn_to_page(gap->start_pfn);
+ cur_end_pgp = (unsigned long)
+ pfn_to_page(gap->end_pfn);
+ if (((unsigned long)pg >= cur_start_pgp) &&
+ ((unsigned long)pg < cur_end_pgp)) {
+ return;
+ }
+ }
+
+ /* This frame is currently backed; online the page. */
+ __online_page_set_limits(pg);
+ __online_page_increment_counters(pg);
+ __online_page_free(pg);
+}
+
+static void hv_bring_pgs_online(struct hv_hotadd_state *has,
+ unsigned long start_pfn, unsigned long size)
{
int i;
- for (i = 0; i < size; i++) {
- struct page *pg;
- pg = pfn_to_page(start_pfn + i);
- __online_page_set_limits(pg);
- __online_page_increment_counters(pg);
- __online_page_free(pg);
- }
+ for (i = 0; i < size; i++)
+ hv_page_online_one(has, pfn_to_page(start_pfn + i));
}
static void hv_mem_hot_add(unsigned long start, unsigned long size,
@@ -684,26 +722,24 @@ static void hv_online_page(struct page *pg)
list_for_each(cur, &dm_device.ha_region_list) {
has = list_entry(cur, struct hv_hotadd_state, list);
cur_start_pgp = (unsigned long)
- pfn_to_page(has->covered_start_pfn);
- cur_end_pgp = (unsigned long)pfn_to_page(has->covered_end_pfn);
+ pfn_to_page(has->start_pfn);
+ cur_end_pgp = (unsigned long)pfn_to_page(has->end_pfn);
- if (((unsigned long)pg >= cur_start_pgp) &&
- ((unsigned long)pg < cur_end_pgp)) {
- /*
- * This frame is currently backed; online the
- * page.
- */
- __online_page_set_limits(pg);
- __online_page_increment_counters(pg);
- __online_page_free(pg);
- }
+ /* The page belongs to a different HAS. */
+ if (((unsigned long)pg < cur_start_pgp) ||
+ ((unsigned long)pg >= cur_end_pgp))
+ continue;
+
+ hv_page_online_one(has, pg);
+ break;
}
}
-static bool pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
+static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
{
struct list_head *cur;
struct hv_hotadd_state *has;
+ struct hv_hotadd_gap *gap;
unsigned long residual, new_inc;
if (list_empty(&dm_device.ha_region_list))
@@ -718,6 +754,24 @@ static bool pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
*/
if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn)
continue;
+
+ /*
+ * If the current start pfn is not where the covered_end
+ * is, create a gap and update covered_end_pfn.
+ */
+ if (has->covered_end_pfn != start_pfn) {
+ gap = kzalloc(sizeof(struct hv_hotadd_gap), GFP_ATOMIC);
+ if (!gap)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&gap->list);
+ gap->start_pfn = has->covered_end_pfn;
+ gap->end_pfn = start_pfn;
+ list_add_tail(&gap->list, &has->gap_list);
+
+ has->covered_end_pfn = start_pfn;
+ }
+
/*
* If the current hot add-request extends beyond
* our current limit; extend it.
@@ -734,19 +788,10 @@ static bool pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
has->end_pfn += new_inc;
}
- /*
- * If the current start pfn is not where the covered_end
- * is, update it.
- */
-
- if (has->covered_end_pfn != start_pfn)
- has->covered_end_pfn = start_pfn;
-
- return true;
-
+ return 1;
}
- return false;
+ return 0;
}
static unsigned long handle_pg_range(unsigned long pg_start,
@@ -785,6 +830,8 @@ static unsigned long handle_pg_range(unsigned long pg_start,
if (pgs_ol > pfn_cnt)
pgs_ol = pfn_cnt;
+ has->covered_end_pfn += pgs_ol;
+ pfn_cnt -= pgs_ol;
/*
* Check if the corresponding memory block is already
* online by checking its last previously backed page.
@@ -793,10 +840,8 @@ static unsigned long handle_pg_range(unsigned long pg_start,
*/
if (start_pfn > has->start_pfn &&
!PageReserved(pfn_to_page(start_pfn - 1)))
- hv_bring_pgs_online(start_pfn, pgs_ol);
+ hv_bring_pgs_online(has, start_pfn, pgs_ol);
- has->covered_end_pfn += pgs_ol;
- pfn_cnt -= pgs_ol;
}
if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) {
@@ -834,13 +879,19 @@ static unsigned long process_hot_add(unsigned long pg_start,
unsigned long rg_size)
{
struct hv_hotadd_state *ha_region = NULL;
+ int covered;
if (pfn_cnt == 0)
return 0;
- if (!dm_device.host_specified_ha_region)
- if (pfn_covered(pg_start, pfn_cnt))
+ if (!dm_device.host_specified_ha_region) {
+ covered = pfn_covered(pg_start, pfn_cnt);
+ if (covered < 0)
+ return 0;
+
+ if (covered)
goto do_pg_range;
+ }
/*
* If the host has specified a hot-add range; deal with it first.
@@ -852,6 +903,7 @@ static unsigned long process_hot_add(unsigned long pg_start,
return 0;
INIT_LIST_HEAD(&ha_region->list);
+ INIT_LIST_HEAD(&ha_region->gap_list);
list_add_tail(&ha_region->list, &dm_device.ha_region_list);
ha_region->start_pfn = rg_start;
@@ -1585,6 +1637,7 @@ static int balloon_remove(struct hv_device *dev)
struct hv_dynmem_device *dm = hv_get_drvdata(dev);
struct list_head *cur, *tmp;
struct hv_hotadd_state *has;
+ struct hv_hotadd_gap *gap, *tmp_gap;
if (dm->num_pages_ballooned != 0)
pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned);
@@ -1601,6 +1654,10 @@ static int balloon_remove(struct hv_device *dev)
#endif
list_for_each_safe(cur, tmp, &dm->ha_region_list) {
has = list_entry(cur, struct hv_hotadd_state, list);
+ list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) {
+ list_del(&gap->list);
+ kfree(gap);
+ }
list_del(&has->list);
kfree(has);
}