[PATCH] KVM: MMU: Never free a shadow page actively serving as a root
We always need cr3 to point to something valid, so if we detect that we're
freeing a root page, simply push it back to the top of the active list.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 201b273..b24a86e 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -134,6 +134,7 @@
*/
int global; /* Set if all ptes in this page are global */
int multimapped; /* More than one parent_pte? */
+ int root_count; /* Currently serving as active root */
union {
u64 *parent_pte; /* !multimapped */
struct hlist_head parent_ptes; /* multimapped, kvm_pte_chain */