KVM: MMU: cleanup spte_write_protect

Use __drop_large_spte to cleanup this function and comment spte_write_protect

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 29 insertions, 16 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d04d6305a725..ed9e96806082 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1050,7 +1050,33 @@ static void drop_spte(struct kvm *kvm, u64 *sptep)
                 rmap_remove(kvm, sptep);
 }
 
-/* Return true if the spte is dropped. */
+
+static bool __drop_large_spte(struct kvm *kvm, u64 *sptep)
+{
+        if (is_large_pte(*sptep)) {
+                WARN_ON(page_header(__pa(sptep))->role.level ==
+                        PT_PAGE_TABLE_LEVEL);
+                drop_spte(kvm, sptep);
+                --kvm->stat.lpages;
+                return true;
+        }
+
+        return false;
+}
+
+static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep)
+{
+        if (__drop_large_spte(vcpu->kvm, sptep))
+                kvm_flush_remote_tlbs(vcpu->kvm);
+}
+
+/*
+ * Write-protect on the specified @sptep due to dirty page logging or
+ * protecting shadow page table. @flush indicates whether tlb need be
+ * flushed.
+ *
+ * Return true if the spte is dropped.
+ */
 static bool spte_write_protect(struct kvm *kvm, u64 *sptep, bool *flush)
 {
         u64 spte = *sptep;
@@ -1061,13 +1087,9 @@ static bool spte_write_protect(struct kvm *kvm, u64 *sptep, bool *flush)
         rmap_printk("rmap_write_protect: spte %p %llx\n", sptep, *sptep);
 
         *flush |= true;
-        if (is_large_pte(spte)) {
-                WARN_ON(page_header(__pa(sptep))->role.level ==
-                       PT_PAGE_TABLE_LEVEL);
-                drop_spte(kvm, sptep);
-                --kvm->stat.lpages;
+
+        if (__drop_large_spte(kvm, sptep))
                 return true;
-        }
 
         spte = spte & ~PT_WRITABLE_MASK;
         mmu_spte_update(sptep, spte);
@@ -1878,15 +1900,6 @@ static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
         mmu_spte_set(sptep, spte);
 }
 
-static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep)
-{
-        if (is_large_pte(*sptep)) {
-                drop_spte(vcpu->kvm, sptep);
-                --vcpu->kvm->stat.lpages;
-                kvm_flush_remote_tlbs(vcpu->kvm);
-        }
-}
-
 static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep,
                                    unsigned direct_access)
 {