diff mbox

[5/8] KVM: MMU: Delete hash_link node in kvm_mmu_prepare_zap_page()

Message ID 20130123191617.029d218d.yoshikawa_takuya_b1@lab.ntt.co.jp (mailing list archive)
State New, archived
Headers show

Commit Message

Takuya Yoshikawa Jan. 23, 2013, 10:16 a.m. UTC 
Now that we are using for_each_gfn_indirect_valid_sp_safe, we can safely
delete the node by correctly updating the pointer to the next one.

The only case we need to care about is when mmu_zap_unsync_children()
has zapped anything other than the current one.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
---
 arch/x86/kvm/mmu.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
diff mbox

Patch

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d5bf373..a72c573 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1469,7 +1469,6 @@  static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr)
 static void kvm_mmu_isolate_page(struct kvm_mmu_page *sp)
 {
 	ASSERT(is_empty_shadow_page(sp->spt));
-	hlist_del(&sp->hash_link);
 	if (!sp->role.direct)
 		free_page((unsigned long)sp->gfns);
 }
@@ -2111,9 +2110,15 @@  static int kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp,
 		unaccount_shadowed(kvm, sp->gfn);
 	if (sp->unsync)
 		kvm_unlink_unsync_page(kvm, sp);
+
+	/* Next entry might be deleted by mmu_zap_unsync_children(). */
+	if (npos && ret)
+		npos->hn = sp->hash_link.next;
+
 	if (!sp->root_count) {
 		/* Count self */
 		ret++;
+		hlist_del(&sp->hash_link);
 		list_move(&sp->link, invalid_list);
 		kvm_mod_used_mmu_pages(kvm, -1);
 	} else {