KVM: MMU: mmu_parent_walk
Introduce a function to walk all parents of a given page, invoking a handler.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e89af1d..b82abee 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -147,6 +147,8 @@
u64 addr, u64 *spte, int level);
};
+typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp);
+
static struct kmem_cache *pte_chain_cache;
static struct kmem_cache *rmap_desc_cache;
static struct kmem_cache *mmu_page_header_cache;
@@ -862,6 +864,31 @@
BUG();
}
+
+static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+ mmu_parent_walk_fn fn)
+{
+ struct kvm_pte_chain *pte_chain;
+ struct hlist_node *node;
+ struct kvm_mmu_page *parent_sp;
+ int i;
+
+ if (!sp->multimapped && sp->parent_pte) {
+ parent_sp = page_header(__pa(sp->parent_pte));
+ fn(vcpu, parent_sp);
+ mmu_parent_walk(vcpu, parent_sp, fn);
+ return;
+ }
+ hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
+ for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
+ if (!pte_chain->parent_ptes[i])
+ break;
+ parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
+ fn(vcpu, parent_sp);
+ mmu_parent_walk(vcpu, parent_sp, fn);
+ }
+}
+
static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *sp)
{