diff mbox series

[v3,7/7] KVM: x86/mmu: Merge all handle_changed_pte* functions.

Message ID 20230211014626.3659152-8-vipinsh@google.com (mailing list archive)
State New, archived
Headers show
Series Optimize clear dirty log | expand

Commit Message

Vipin Sharma Feb. 11, 2023, 1:46 a.m. UTC 
__handle_changed_pte() and handle_changed_spte_acc_track() are always
used together. Merge these two functions and name the new function
handle_changed_pte(). Remove the existing handle_changed_pte() function
which just calls __handle_changed_pte and
handle_changed_spte_acc_track().

This converges SPTEs change handling code to a single place.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 42 +++++++++++---------------------------
 1 file changed, 12 insertions(+), 30 deletions(-)

Comments

David Matlack Feb. 22, 2023, 7:42 p.m. UTC | #1 
On Fri, Feb 10, 2023 at 05:46:26PM -0800, Vipin Sharma wrote:
> __handle_changed_pte() and handle_changed_spte_acc_track() are always
> used together. Merge these two functions and name the new function

nit: State what the patch does first.

> handle_changed_pte(). Remove the existing handle_changed_pte() function
> which just calls __handle_changed_pte and
> handle_changed_spte_acc_track().

s/_pte/_spte/

> 
> This converges SPTEs change handling code to a single place.
> 
> Signed-off-by: Vipin Sharma <vipinsh@google.com>
> Reviewed-by: Ben Gardon <bgardon@google.com>

Nice cleanup! Commit message nits aside,

Reviewed-by: David Matlack <dmatlack@google.com>

> ---
>  arch/x86/kvm/mmu/tdp_mmu.c | 42 +++++++++++---------------------------
>  1 file changed, 12 insertions(+), 30 deletions(-)
> 
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index 0c031319e901..67538ec48ce5 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -334,17 +334,6 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
>  				u64 old_spte, u64 new_spte, int level,
>  				bool shared);
>  
> -static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
> -{
> -	if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level))
> -		return;
> -
> -	if (is_accessed_spte(old_spte) &&
> -	    (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) ||
> -	     spte_to_pfn(old_spte) != spte_to_pfn(new_spte)))
> -		kvm_set_pfn_accessed(spte_to_pfn(old_spte));
> -}
> -
>  static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
>  {
>  	kvm_account_pgtable_pages((void *)sp->spt, +1);
> @@ -487,7 +476,7 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
>  }
>  
>  /**
> - * __handle_changed_spte - handle bookkeeping associated with an SPTE change
> + * handle_changed_spte - handle bookkeeping associated with an SPTE change
>   * @kvm: kvm instance
>   * @as_id: the address space of the paging structure the SPTE was a part of
>   * @gfn: the base GFN that was mapped by the SPTE
> @@ -501,9 +490,9 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
>   * Handle bookkeeping that might result from the modification of a SPTE.
>   * This function must be called for all TDP SPTE modifications.
>   */
> -static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
> -				  u64 old_spte, u64 new_spte, int level,
> -				  bool shared)
> +static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
> +				u64 old_spte, u64 new_spte, int level,
> +				bool shared)
>  {
>  	bool was_present = is_shadow_present_pte(old_spte);
>  	bool is_present = is_shadow_present_pte(new_spte);
> @@ -587,15 +576,10 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
>  	if (was_present && !was_leaf &&
>  	    (is_leaf || !is_present || WARN_ON_ONCE(pfn_changed)))
>  		handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared);
> -}
>  
> -static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
> -				u64 old_spte, u64 new_spte, int level,
> -				bool shared)
> -{
> -	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level,
> -			      shared);
> -	handle_changed_spte_acc_track(old_spte, new_spte, level);
> +	if (was_leaf && is_accessed_spte(old_spte) &&
> +	    (!is_present || !is_accessed_spte(new_spte) || pfn_changed))
> +		kvm_set_pfn_accessed(spte_to_pfn(old_spte));
>  }
>  
>  /*
> @@ -638,9 +622,8 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
>  	if (!try_cmpxchg64(sptep, &iter->old_spte, new_spte))
>  		return -EBUSY;
>  
> -	__handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
> -			      new_spte, iter->level, true);
> -	handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level);
> +	handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
> +			    new_spte, iter->level, true);
>  
>  	return 0;
>  }
> @@ -705,8 +688,7 @@ static u64 tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
>  
>  	old_spte = kvm_tdp_mmu_write_spte(sptep, old_spte, new_spte, level);
>  
> -	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
> -	handle_changed_spte_acc_track(old_spte, new_spte, level);
> +	handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
>  	return old_spte;
>  }
>  
> @@ -1276,7 +1258,7 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter,
>  	 * Note, when changing a read-only SPTE, it's not strictly necessary to
>  	 * zero the SPTE before setting the new PFN, but doing so preserves the
>  	 * invariant that the PFN of a present * leaf SPTE can never change.
> -	 * See __handle_changed_spte().
> +	 * See handle_changed_spte().
>  	 */
>  	tdp_mmu_iter_set_spte(kvm, iter, 0);
>  
> @@ -1301,7 +1283,7 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
>  	/*
>  	 * No need to handle the remote TLB flush under RCU protection, the
>  	 * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
> -	 * shadow page.  See the WARN on pfn_changed in __handle_changed_spte().
> +	 * shadow page. See the WARN on pfn_changed in handle_changed_spte().
>  	 */
>  	return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn);
>  }
> -- 
> 2.39.1.581.gbfd45094c4-goog
>
Sean Christopherson March 17, 2023, 10:51 p.m. UTC | #2 
On Fri, Feb 10, 2023, Vipin Sharma wrote:
> @@ -1301,7 +1283,7 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
>  	/*
>  	 * No need to handle the remote TLB flush under RCU protection, the
>  	 * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
> -	 * shadow page.  See the WARN on pfn_changed in __handle_changed_spte().
> +	 * shadow page. See the WARN on pfn_changed in handle_changed_spte().

I was just starting to think you're an ok person, and then I find out you're a
heretic that only puts a single space after periods.  ;-)
Vipin Sharma March 17, 2023, 11:48 p.m. UTC | #3 
On Fri, Mar 17, 2023 at 3:51 PM Sean Christopherson <seanjc@google.com> wrote:
>
> On Fri, Feb 10, 2023, Vipin Sharma wrote:
> > @@ -1301,7 +1283,7 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
> >       /*
> >        * No need to handle the remote TLB flush under RCU protection, the
> >        * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
> > -      * shadow page.  See the WARN on pfn_changed in __handle_changed_spte().
> > +      * shadow page. See the WARN on pfn_changed in handle_changed_spte().
>
> I was just starting to think you're an ok person, and then I find out you're a
> heretic that only puts a single space after periods.  ;-)

I know, I know, I can't help it. I just love the way single space
looks after periods.
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 0c031319e901..67538ec48ce5 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -334,17 +334,6 @@  static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 				u64 old_spte, u64 new_spte, int level,
 				bool shared);
 
-static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
-{
-	if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level))
-		return;
-
-	if (is_accessed_spte(old_spte) &&
-	    (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) ||
-	     spte_to_pfn(old_spte) != spte_to_pfn(new_spte)))
-		kvm_set_pfn_accessed(spte_to_pfn(old_spte));
-}
-
 static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	kvm_account_pgtable_pages((void *)sp->spt, +1);
@@ -487,7 +476,7 @@  static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
 }
 
 /**
- * __handle_changed_spte - handle bookkeeping associated with an SPTE change
+ * handle_changed_spte - handle bookkeeping associated with an SPTE change
  * @kvm: kvm instance
  * @as_id: the address space of the paging structure the SPTE was a part of
  * @gfn: the base GFN that was mapped by the SPTE
@@ -501,9 +490,9 @@  static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
  * Handle bookkeeping that might result from the modification of a SPTE.
  * This function must be called for all TDP SPTE modifications.
  */
-static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
-				  u64 old_spte, u64 new_spte, int level,
-				  bool shared)
+static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
+				u64 old_spte, u64 new_spte, int level,
+				bool shared)
 {
 	bool was_present = is_shadow_present_pte(old_spte);
 	bool is_present = is_shadow_present_pte(new_spte);
@@ -587,15 +576,10 @@  static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 	if (was_present && !was_leaf &&
 	    (is_leaf || !is_present || WARN_ON_ONCE(pfn_changed)))
 		handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared);
-}
 
-static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
-				u64 old_spte, u64 new_spte, int level,
-				bool shared)
-{
-	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level,
-			      shared);
-	handle_changed_spte_acc_track(old_spte, new_spte, level);
+	if (was_leaf && is_accessed_spte(old_spte) &&
+	    (!is_present || !is_accessed_spte(new_spte) || pfn_changed))
+		kvm_set_pfn_accessed(spte_to_pfn(old_spte));
 }
 
 /*
@@ -638,9 +622,8 @@  static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
 	if (!try_cmpxchg64(sptep, &iter->old_spte, new_spte))
 		return -EBUSY;
 
-	__handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
-			      new_spte, iter->level, true);
-	handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level);
+	handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
+			    new_spte, iter->level, true);
 
 	return 0;
 }
@@ -705,8 +688,7 @@  static u64 tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
 
 	old_spte = kvm_tdp_mmu_write_spte(sptep, old_spte, new_spte, level);
 
-	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
-	handle_changed_spte_acc_track(old_spte, new_spte, level);
+	handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
 	return old_spte;
 }
 
@@ -1276,7 +1258,7 @@  static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter,
 	 * Note, when changing a read-only SPTE, it's not strictly necessary to
 	 * zero the SPTE before setting the new PFN, but doing so preserves the
 	 * invariant that the PFN of a present * leaf SPTE can never change.
-	 * See __handle_changed_spte().
+	 * See handle_changed_spte().
 	 */
 	tdp_mmu_iter_set_spte(kvm, iter, 0);
 
@@ -1301,7 +1283,7 @@  bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 	/*
 	 * No need to handle the remote TLB flush under RCU protection, the
 	 * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
-	 * shadow page.  See the WARN on pfn_changed in __handle_changed_spte().
+	 * shadow page. See the WARN on pfn_changed in handle_changed_spte().
 	 */
 	return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn);
 }