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>

1 files changed, 9 insertions, 4 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index b82abee78f17..c9b4b902527b 100644
--- 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);