KVM: MMU: Make flooding detection work when guest page faults are bypassed

When we allow guest page faults to reach the guests directly, we lose
the fault tracking which allows us to detect demand paging.  So we provide
an alternate mechnism by clearing the accessed bit when we set a pte, and
checking it later to see if the guest actually used it.

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 7de948e9e64e..08ffc829f07f 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -346,6 +346,7 @@ struct kvm_vcpu {
 
 	gfn_t last_pt_write_gfn;
 	int   last_pt_write_count;
+	u64  *last_pte_updated;
 
 	struct kvm_guest_debug guest_debug;