[v2,02/28] KVM: x86/mmu: Add comment on __tdp_mmu_set_spte

Commit Message

Ben Gardon Feb. 2, 2021, 6:57 p.m. UTC

__tdp_mmu_set_spte is a very important function in the TDP MMU which
already accepts several arguments and will take more in future commits.
To offset this complexity, add a comment to the function describing each
of the arguemnts.

No functional change intended.

Reviewed-by: Peter Feiner <[e-mail]>
Acked-by: Paolo Bonzini <[e-mail]>
Signed-off-by: Ben Gardon <[e-mail]>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Patch

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index e9f9ff81a38e..3d8cca238eba 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -357,6 +357,22 @@  static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 				      new_spte, level);
 }
 
+/*
+ * __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
+ * @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
+ *		      unset in that case prevents page accesses from being
+ *		      double counted.
+ * @record_dirty_log: Record the page as dirty in the dirty bitmap if
+ *		      appropriate for the change being made. Should be set
+ *		      unless performing certain dirty logging operations.
+ *		      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)