KVM: Fix dirty bit tracking for slots with large pages

When slot is already allocated and being asked to be tracked we need
to break the large pages.

This code flush the mmu when someone ask a slot to start dirty bit
tracking.

Cc: stable@kernel.org
Signed-off-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 764554350ed86f41b26f45eb840ad02138a55081..013a5b3e9f75cd473832cb63d81723198e23063d 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1194,6 +1194,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
                if (!new.dirty_bitmap)
                        goto out_free;
                memset(new.dirty_bitmap, 0, dirty_bytes);
+               if (old.npages)
+                       kvm_arch_flush_shadow(kvm);
        }
 #endif /* not defined CONFIG_S390 */