[PATCH 18/28] KVM: x86/mmu: Refactor low-level TDP MMU set SPTE helper to take raw vals

Sean Christopherson
2021-11-20T04:52:47Z

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>
---
arch/x86/kvm/mmu/tdp_mmu.c | 47 +++++++++++++++++++++++---------------
1 file changed, 29 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index cc8d021a1ba5..7d354344924d 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -622,9 +622,13 @@ static inline bool 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
@@ -636,9 +640,9 @@ static inline bool 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)
{
lockdep_assert_held_write(&kvm->mmu_lock);

@@ -649,39 +653,46 @@ 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)
+{
+ __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) \
--
2.34.0.rc2.393.gf8c9666880-goog