KVM: MMU: Add link_shadow_page() helper

To simplify the process of fetching an spte, add a helper that links
a shadow page to an spte.

Reviewed-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

2 files changed, 12 insertions, 5 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 89d7a2cae53b..df3a7a79cce3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1482,6 +1482,16 @@ static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
         --iterator->level;
 }
 
+static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
+{
+        u64 spte;
+
+        spte = __pa(sp->spt)
+                | PT_PRESENT_MASK | PT_ACCESSED_MASK
+                | PT_WRITABLE_MASK | PT_USER_MASK;
+        *sptep = spte;
+}
+
 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
                                          struct kvm_mmu_page *sp)
 {
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 1cea41cad069..36dc0749c878 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -309,7 +309,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 {
         unsigned access = gw->pt_access;
         struct kvm_mmu_page *sp;
-        u64 spte, *sptep = NULL;
+        u64 *sptep = NULL;
         int direct;
         gfn_t table_gfn;
         int r;
@@ -395,10 +395,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                         }
                 }
 
-                spte = __pa(sp->spt)
-                        | PT_PRESENT_MASK | PT_ACCESSED_MASK
-                        | PT_WRITABLE_MASK | PT_USER_MASK;
-                *sptep = spte;
+                link_shadow_page(sptep, sp);
         }
 
         return sptep;