KVM: x86: MMU: Move initialization of parent_ptes out from kvm_mmu_alloc_page()

Make kvm_mmu_alloc_page() do just what its name tells to do, and remove
the extra allocation error check and zero-initialization of parent_ptes:
shadow page headers allocated by kmem_cache_zalloc() are always in the
per-VCPU pools.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5b249d4f4da1ee719b4b10ff63501a723b2c8e42..7f46e3e7ebd1afbfdd8448cc38a8e7f29dcfa467 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1726,8 +1726,7 @@ static void drop_parent_pte(struct kvm_mmu_page *sp,
        mmu_spte_clear_no_track(parent_pte);
 }
 
-static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
-                                              u64 *parent_pte, int direct)
+static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct)
 {
        struct kvm_mmu_page *sp;
 
@@ -1743,8 +1742,6 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
         * this feature. See the comments in kvm_zap_obsolete_pages().
         */
        list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
-       sp->parent_ptes.val = 0;
-       mmu_page_add_parent_pte(vcpu, sp, parent_pte);
        kvm_mod_used_mmu_pages(vcpu->kvm, +1);
        return sp;
 }
@@ -2133,10 +2130,13 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                trace_kvm_mmu_get_page(sp, false);
                return sp;
        }
+
        ++vcpu->kvm->stat.mmu_cache_miss;
-       sp = kvm_mmu_alloc_page(vcpu, parent_pte, direct);
-       if (!sp)
-               return sp;
+
+       sp = kvm_mmu_alloc_page(vcpu, direct);
+
+       mmu_page_add_parent_pte(vcpu, sp, parent_pte);
+
        sp->gfn = gfn;
        sp->role = role;
        hlist_add_head(&sp->hash_link,