[patch 08/10] KVM: MMU: awareness of new kvm_mmu_zap_page behaviour

[Marcelo Tosatti <mtosatti@redhat.com>]

[-- Attachment #1: mmu-zap-ret --]
[-- Type: text/plain, Size: 1777 bytes --]

kvm_mmu_zap_page will soon zap the unsynced children of a page. Restart
list walk in such case.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: kvm/arch/x86/kvm/mmu.c
===================================================================
--- kvm.orig/arch/x86/kvm/mmu.c
+++ kvm/arch/x86/kvm/mmu.c
@@ -1112,7 +1112,7 @@ static void kvm_mmu_unlink_parents(struc
 	}
 }
 
-static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	++kvm->stat.mmu_shadow_zapped;
 	kvm_mmu_page_unlink_children(kvm, sp);
@@ -1129,6 +1129,7 @@ static void kvm_mmu_zap_page(struct kvm 
 		kvm_reload_remote_mmus(kvm);
 	}
 	kvm_mmu_reset_last_pte_updated(kvm);
+	return 0;
 }
 
 /*
@@ -1181,8 +1182,9 @@ static int kvm_mmu_unprotect_page(struct
 		if (sp->gfn == gfn && !sp->role.metaphysical) {
 			pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
 				 sp->role.word);
-			kvm_mmu_zap_page(kvm, sp);
 			r = 1;
+			if (kvm_mmu_zap_page(kvm, sp))
+				n = bucket->first;
 		}
 	return r;
 }
@@ -2027,7 +2029,8 @@ void kvm_mmu_pte_write(struct kvm_vcpu *
 			 */
 			pgprintk("misaligned: gpa %llx bytes %d role %x\n",
 				 gpa, bytes, sp->role.word);
-			kvm_mmu_zap_page(vcpu->kvm, sp);
+			if (kvm_mmu_zap_page(vcpu->kvm, sp))
+				n = bucket->first;
 			++vcpu->kvm->stat.mmu_flooded;
 			continue;
 		}
@@ -2260,7 +2263,9 @@ void kvm_mmu_zap_all(struct kvm *kvm)
 
 	spin_lock(&kvm->mmu_lock);
 	list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
-		kvm_mmu_zap_page(kvm, sp);
+		if (kvm_mmu_zap_page(kvm, sp))
+			node = container_of(kvm->arch.active_mmu_pages.next,
+					    struct kvm_mmu_page, link);
 	spin_unlock(&kvm->mmu_lock);
 
 	kvm_flush_remote_tlbs(kvm);

--