KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp

The TDP MMU's own function for the changed-PTE notifier will need to be
update a PTE in the exact same way as the shadow MMU.  Rather than
re-implementing this logic, factor the SPTE creation out of kvm_set_pte_rmapp.

Extracted out of a patch by Ben Gardon. <bgardon@google.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ef4a63a..3dec474 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1747,6 +1747,21 @@ static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
        return kvm_zap_rmapp(kvm, rmap_head);
 }
 
+static u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn)
+{
+       u64 new_spte;
+
+       new_spte = old_spte & ~PT64_BASE_ADDR_MASK;
+       new_spte |= (u64)new_pfn << PAGE_SHIFT;
+
+       new_spte &= ~PT_WRITABLE_MASK;
+       new_spte &= ~SPTE_HOST_WRITEABLE;
+
+       new_spte = mark_spte_for_access_track(new_spte);
+
+       return new_spte;
+}
+
 static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
                             struct kvm_memory_slot *slot, gfn_t gfn, int level,
                             unsigned long data)
@@ -1772,13 +1787,8 @@ restart:
                        pte_list_remove(rmap_head, sptep);
                        goto restart;
                } else {
-                       new_spte = *sptep & ~PT64_BASE_ADDR_MASK;
-                       new_spte |= (u64)new_pfn << PAGE_SHIFT;
-
-                       new_spte &= ~PT_WRITABLE_MASK;
-                       new_spte &= ~SPTE_HOST_WRITEABLE;
-
-                       new_spte = mark_spte_for_access_track(new_spte);
+                       new_spte = kvm_mmu_changed_pte_notifier_make_spte(
+                                       *sptep, new_pfn);
 
                        mmu_spte_clear_track_bits(sptep);
                        mmu_spte_set(sptep, new_spte);