KVM: x86/mmu: Refactor low-level TDP MMU set SPTE helper to take raw values

Refactor __tdp_mmu_set_spte() to work with raw values instead of a
tdp_iter objects so that a future patch can modify SPTEs without doing a
walk, and without having to synthesize a tdp_iter.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20220226001546.360188-13-seanjc@google.com>
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 41175ee..0ffa62a 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -603,9 +603,13 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm *kvm,
 
 /*
  * __tdp_mmu_set_spte - Set a TDP MMU SPTE and handle the associated bookkeeping
- * @kvm: kvm instance
- * @iter: a tdp_iter instance currently on the SPTE that should be set
- * @new_spte: The value the SPTE should be set to
+ * @kvm:             KVM instance
+ * @as_id:           Address space ID, i.e. regular vs. SMM
+ * @sptep:           Pointer to the SPTE
+ * @old_spte:        The current value of the SPTE
+ * @new_spte:        The new value that will be set for the SPTE
+ * @gfn:             The base GFN that was (or will be) mapped by the SPTE
+ * @level:           The level _containing_ the SPTE (its parent PT's level)
  * @record_acc_track: Notify the MM subsystem of changes to the accessed state
  *                   of the page. Should be set unless handling an MMU
  *                   notifier for access tracking. Leaving record_acc_track
@@ -617,12 +621,10 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm *kvm,
  *                   Leaving record_dirty_log unset in that case prevents page
  *                   writes from being double counted.
  */
-static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
-                                     u64 new_spte, bool record_acc_track,
-                                     bool record_dirty_log)
+static void __tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
+                              u64 old_spte, u64 new_spte, gfn_t gfn, int level,
+                              bool record_acc_track, bool record_dirty_log)
 {
-       WARN_ON_ONCE(iter->yielded);
-
        lockdep_assert_held_write(&kvm->mmu_lock);
 
        /*
@@ -632,39 +634,48 @@ static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
         * should be used. If operating under the MMU lock in write mode, the
         * use of the removed SPTE should not be necessary.
         */
-       WARN_ON(is_removed_spte(iter->old_spte) || is_removed_spte(new_spte));
+       WARN_ON(is_removed_spte(old_spte) || is_removed_spte(new_spte));
 
-       kvm_tdp_mmu_write_spte(iter->sptep, new_spte);
+       kvm_tdp_mmu_write_spte(sptep, new_spte);
+
+       __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
 
-       __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
-                             new_spte, iter->level, false);
        if (record_acc_track)
-               handle_changed_spte_acc_track(iter->old_spte, new_spte,
-                                             iter->level);
+               handle_changed_spte_acc_track(old_spte, new_spte, level);
        if (record_dirty_log)
-               handle_changed_spte_dirty_log(kvm, iter->as_id, iter->gfn,
-                                             iter->old_spte, new_spte,
-                                             iter->level);
+               handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte,
+                                             new_spte, level);
+}
+
+static inline void _tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
+                                    u64 new_spte, bool record_acc_track,
+                                    bool record_dirty_log)
+{
+       WARN_ON_ONCE(iter->yielded);
+
+       __tdp_mmu_set_spte(kvm, iter->as_id, iter->sptep, iter->old_spte,
+                          new_spte, iter->gfn, iter->level,
+                          record_acc_track, record_dirty_log);
 }
 
 static inline void tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
                                    u64 new_spte)
 {
-       __tdp_mmu_set_spte(kvm, iter, new_spte, true, true);
+       _tdp_mmu_set_spte(kvm, iter, new_spte, true, true);
 }
 
 static inline void tdp_mmu_set_spte_no_acc_track(struct kvm *kvm,
                                                 struct tdp_iter *iter,
                                                 u64 new_spte)
 {
-       __tdp_mmu_set_spte(kvm, iter, new_spte, false, true);
+       _tdp_mmu_set_spte(kvm, iter, new_spte, false, true);
 }
 
 static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
                                                 struct tdp_iter *iter,
                                                 u64 new_spte)
 {
-       __tdp_mmu_set_spte(kvm, iter, new_spte, true, false);
+       _tdp_mmu_set_spte(kvm, iter, new_spte, true, false);
 }
 
 #define tdp_root_for_each_pte(_iter, _root, _start, _end) \