xen/balloon: Share common memory reservation routines
Memory {increase|decrease}_reservation and VA mappings update/reset
code used in balloon driver can be made common, so other drivers can
also re-use the same functionality without open-coding.
Create a dedicated file for the shared code and export corresponding
symbols for other kernel modules.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 065f0b6..e12bb25 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -71,6 +71,7 @@
#include <xen/balloon.h>
#include <xen/features.h>
#include <xen/page.h>
+#include <xen/mem-reservation.h>
static int xen_hotplug_unpopulated;
@@ -157,13 +158,6 @@ static DECLARE_DELAYED_WORK(balloon_worker, balloon_process);
#define GFP_BALLOON \
(GFP_HIGHUSER | __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC)
-static void scrub_page(struct page *page)
-{
-#ifdef CONFIG_XEN_SCRUB_PAGES
- clear_highpage(page);
-#endif
-}
-
/* balloon_append: add the given page to the balloon. */
static void __balloon_append(struct page *page)
{
@@ -463,11 +457,6 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
int rc;
unsigned long i;
struct page *page;
- struct xen_memory_reservation reservation = {
- .address_bits = 0,
- .extent_order = EXTENT_ORDER,
- .domid = DOMID_SELF
- };
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
@@ -479,16 +468,11 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
break;
}
- /* XENMEM_populate_physmap requires a PFN based on Xen
- * granularity.
- */
frame_list[i] = page_to_xen_pfn(page);
page = balloon_next_page(page);
}
- set_xen_guest_handle(reservation.extent_start, frame_list);
- reservation.nr_extents = nr_pages;
- rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
+ rc = xenmem_reservation_increase(nr_pages, frame_list);
if (rc <= 0)
return BP_EAGAIN;
@@ -496,29 +480,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
page = balloon_retrieve(false);
BUG_ON(page == NULL);
-#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. */
- if (!PageHighMem(page)) {
- int ret;
- ret = HYPERVISOR_update_va_mapping(
- (unsigned long)__va(pfn << PAGE_SHIFT),
- mfn_pte(frame_list[i], PAGE_KERNEL),
- 0);
- BUG_ON(ret);
- }
- }
-#endif
+ xenmem_reservation_va_mapping_update(1, &page, &frame_list[i]);
/* Relinquish the page back to the allocator. */
free_reserved_page(page);
@@ -535,11 +497,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
unsigned long i;
struct page *page, *tmp;
int ret;
- struct xen_memory_reservation reservation = {
- .address_bits = 0,
- .extent_order = EXTENT_ORDER,
- .domid = DOMID_SELF
- };
LIST_HEAD(pages);
if (nr_pages > ARRAY_SIZE(frame_list))
@@ -553,7 +510,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
break;
}
adjust_managed_page_count(page, -1);
- scrub_page(page);
+ xenmem_reservation_scrub_page(page);
list_add(&page->lru, &pages);
}
@@ -572,28 +529,10 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
*/
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);
+ xenmem_reservation_va_mapping_reset(1, &page);
- 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),
- __pte_ma(0), 0);
- BUG_ON(ret);
- }
- __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
- }
-#endif
list_del(&page->lru);
balloon_append(page);
@@ -601,9 +540,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
flush_tlb_all();
- set_xen_guest_handle(reservation.extent_start, frame_list);
- reservation.nr_extents = nr_pages;
- ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
+ ret = xenmem_reservation_decrease(nr_pages, frame_list);
BUG_ON(ret != nr_pages);
balloon_stats.current_pages -= nr_pages;
