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-rw-r--r--drivers/xen/balloon.c70
1 files changed, 55 insertions, 15 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index f56662324a47..b50d22960ce7 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -113,6 +113,12 @@ static struct ctl_table xen_root[] = {
#endif
/*
+ * Use one extent per PAGE_SIZE to avoid to break down the page into
+ * multiple frame.
+ */
+#define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1)
+
+/*
* balloon_process() state:
*
* BP_DONE: done or nothing to do,
@@ -304,6 +310,12 @@ static enum bp_state reserve_additional_memory(void)
nid = memory_add_physaddr_to_nid(resource->start);
#ifdef CONFIG_XEN_HAVE_PVMMU
+ /*
+ * We don't support PV MMU when Linux and Xen is using
+ * different page granularity.
+ */
+ BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
+
/*
* add_memory() will build page tables for the new memory so
* the p2m must contain invalid entries so the correct
@@ -384,11 +396,11 @@ static bool balloon_is_inflated(void)
static enum bp_state increase_reservation(unsigned long nr_pages)
{
int rc;
- unsigned long pfn, i;
+ unsigned long i;
struct page *page;
struct xen_memory_reservation reservation = {
.address_bits = 0,
- .extent_order = 0,
+ .extent_order = EXTENT_ORDER,
.domid = DOMID_SELF
};
@@ -401,7 +413,11 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
nr_pages = i;
break;
}
- frame_list[i] = page_to_pfn(page);
+
+ /* XENMEM_populate_physmap requires a PFN based on Xen
+ * granularity.
+ */
+ frame_list[i] = page_to_xen_pfn(page);
page = balloon_next_page(page);
}
@@ -415,10 +431,16 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
page = balloon_retrieve(false);
BUG_ON(page == NULL);
- pfn = page_to_pfn(page);
-
#ifdef CONFIG_XEN_HAVE_PVMMU
+ /*
+ * We don't support PV MMU when Linux and Xen is using
+ * different page granularity.
+ */
+ BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
+
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ unsigned long pfn = page_to_pfn(page);
+
set_phys_to_machine(pfn, frame_list[i]);
/* Link back into the page tables if not highmem. */
@@ -445,14 +467,15 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
{
enum bp_state state = BP_DONE;
- unsigned long pfn, i;
- struct page *page;
+ unsigned long i;
+ struct page *page, *tmp;
int ret;
struct xen_memory_reservation reservation = {
.address_bits = 0,
- .extent_order = 0,
+ .extent_order = EXTENT_ORDER,
.domid = DOMID_SELF
};
+ LIST_HEAD(pages);
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
@@ -465,8 +488,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
break;
}
scrub_page(page);
-
- frame_list[i] = page_to_pfn(page);
+ list_add(&page->lru, &pages);
}
/*
@@ -478,14 +500,25 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
*/
kmap_flush_unused();
- /* Update direct mapping, invalidate P2M, and add to balloon. */
- for (i = 0; i < nr_pages; i++) {
- pfn = frame_list[i];
- frame_list[i] = pfn_to_gfn(pfn);
- page = pfn_to_page(pfn);
+ /*
+ * Setup the frame, update direct mapping, invalidate P2M,
+ * and add to balloon.
+ */
+ i = 0;
+ list_for_each_entry_safe(page, tmp, &pages, lru) {
+ /* XENMEM_decrease_reservation requires a GFN */
+ frame_list[i++] = xen_page_to_gfn(page);
#ifdef CONFIG_XEN_HAVE_PVMMU
+ /*
+ * We don't support PV MMU when Linux and Xen is using
+ * different page granularity.
+ */
+ BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
+
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ unsigned long pfn = page_to_pfn(page);
+
if (!PageHighMem(page)) {
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
@@ -495,6 +528,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
#endif
+ list_del(&page->lru);
balloon_append(page);
}
@@ -603,6 +637,12 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages)
if (page) {
pages[pgno++] = page;
#ifdef CONFIG_XEN_HAVE_PVMMU
+ /*
+ * We don't support PV MMU when Linux and Xen is using
+ * different page granularity.
+ */
+ BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
+
ret = xen_alloc_p2m_entry(page_to_pfn(page));
if (ret < 0)
goto out_undo;