Merge tag 'stable/for-linus-3.12-rc0-tag-three' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen balloon driver bug-fixes from Stefano Stabellini:
- fix a preemption bug in xen/balloon.c;
- remove an harmful BUG_ON in xen/balloon.c that can trigger in
non-erroneous situations.
* tag 'stable/for-linus-3.12-rc0-tag-three' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/balloon: remove BUG_ON in increase_reservation
xen/balloon: ensure preemption is disabled when using a scratch page
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 3101cf6..a50c6e3 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -349,8 +349,6 @@
BUG_ON(page == NULL);
pfn = page_to_pfn(page);
- BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
- phys_to_machine_mapping_valid(pfn));
set_phys_to_machine(pfn, frame_list[i]);
@@ -380,6 +378,7 @@
enum bp_state state = BP_DONE;
unsigned long pfn, i;
struct page *page;
+ struct page *scratch_page;
int ret;
struct xen_memory_reservation reservation = {
.address_bits = 0,
@@ -399,6 +398,8 @@
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
+ scratch_page = get_balloon_scratch_page();
+
for (i = 0; i < nr_pages; i++) {
page = alloc_page(gfp);
if (page == NULL) {
@@ -416,7 +417,7 @@
if (xen_pv_domain() && !PageHighMem(page)) {
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
- pfn_pte(page_to_pfn(__get_cpu_var(balloon_scratch_page)),
+ pfn_pte(page_to_pfn(scratch_page),
PAGE_KERNEL_RO), 0);
BUG_ON(ret);
}
@@ -432,14 +433,14 @@
pfn = mfn_to_pfn(frame_list[i]);
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
unsigned long p;
- struct page *pg;
- pg = __get_cpu_var(balloon_scratch_page);
- p = page_to_pfn(pg);
+ p = page_to_pfn(scratch_page);
__set_phys_to_machine(pfn, pfn_to_mfn(p));
}
balloon_append(pfn_to_page(pfn));
}
+ put_balloon_scratch_page();
+
set_xen_guest_handle(reservation.extent_start, frame_list);
reservation.nr_extents = nr_pages;
ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);