KVM: MMU: awareness of new kvm_mmu_zap_page behaviour

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

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index b82abee78f1769f63be393f86ec646f8ae326705..c9b4b902527b6e93c05e739fd323866c76cf6231 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1078,7 +1078,7 @@ static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
        }
 }
 
-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);
@@ -1095,6 +1095,7 @@ static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
                kvm_reload_remote_mmus(kvm);
        }
        kvm_mmu_reset_last_pte_updated(kvm);
+       return 0;
 }
 
 /*
@@ -1147,8 +1148,9 @@ static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
                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;
 }
@@ -1992,7 +1994,8 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                         */
                        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;
                }
@@ -2226,7 +2229,9 @@ 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);