xen: handle highmem pages correctly when shrinking a domain
Commit 1058a75f07b9bb8323fb5197be5526220f8b75cf ("xen: actually release
memory when shrinking domain") causes a crash if the page being released
is a highmem page.
If a page is highmem then there is no need to unmap it.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 8069d52..2ba8f95 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -299,10 +299,13 @@
scrub_page(page);
- ret = HYPERVISOR_update_va_mapping(
- (unsigned long)__va(pfn << PAGE_SHIFT),
- __pte_ma(0), 0);
- BUG_ON(ret);
+ if (!PageHighMem(page)) {
+ ret = HYPERVISOR_update_va_mapping(
+ (unsigned long)__va(pfn << PAGE_SHIFT),
+ __pte_ma(0), 0);
+ BUG_ON(ret);
+ }
+
}
/* Ensure that ballooned highmem pages don't have kmaps. */