linux-kernel - [Patch v4 07/18] KVM: x86/mmu: Unconditionally count allocations from MMU page caches

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Date:   Mon,  6 Mar 2023 14:41:16 -0800
From:   Vipin Sharma <vipinsh@...gle.com>
To:     seanjc@...gle.com, pbonzini@...hat.com, bgardon@...gle.com,
        dmatlack@...gle.com
Cc:     jmattson@...gle.com, mizhang@...gle.com, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Vipin Sharma <vipinsh@...gle.com>
Subject: [Patch v4 07/18] KVM: x86/mmu: Unconditionally count allocations from
 MMU page caches

Remove count_shadow_page_allocations from struct shadow_page_caches{}.
Remove count_allocation boolean condition check from
mmu_sp_memory_cache_alloc().

Both split_shadow_page_cache and mmu_shadow_page_cache are counted in
global count of unused cache pages. count_shadow_page_allocations
boolean is obsolete and can be removed.

Signed-off-by: Vipin Sharma <vipinsh@...gle.com>
---
 arch/x86/kvm/mmu/mmu.c          | 11 +++--------
 arch/x86/kvm/mmu/mmu_internal.h |  3 +--
 arch/x86/kvm/mmu/tdp_mmu.c      |  3 +--
 3 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 73a0ac9c11ce..0a0962d8108b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2184,7 +2184,6 @@ struct shadow_page_caches {
 	struct kvm_mmu_memory_cache *page_header_cache;
 	struct kvm_mmu_memory_cache *shadow_page_cache;
 	struct kvm_mmu_memory_cache *shadowed_info_cache;
-	bool count_shadow_page_allocation;
 };
 
 static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm,
@@ -2196,8 +2195,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm *kvm,
 	struct kvm_mmu_page *sp;
 
 	sp = kvm_mmu_memory_cache_alloc(caches->page_header_cache);
-	sp->spt = mmu_sp_memory_cache_alloc(caches->shadow_page_cache,
-					    caches->count_shadow_page_allocation);
+	sp->spt = mmu_sp_memory_cache_alloc(caches->shadow_page_cache);
 	if (!role.direct)
 		sp->shadowed_translation = kvm_mmu_memory_cache_alloc(caches->shadowed_info_cache);
 
@@ -2254,7 +2252,6 @@ static struct kvm_mmu_page *kvm_mmu_get_shadow_page(struct kvm_vcpu *vcpu,
 		.page_header_cache = &vcpu->arch.mmu_page_header_cache,
 		.shadow_page_cache = &vcpu->arch.mmu_shadow_page_cache,
 		.shadowed_info_cache = &vcpu->arch.mmu_shadowed_info_cache,
-		.count_shadow_page_allocation = true,
 	};
 
 	return __kvm_mmu_get_shadow_page(vcpu->kvm, vcpu, &caches, gfn, role);
@@ -6330,7 +6327,6 @@ static struct kvm_mmu_page *shadow_mmu_get_sp_for_split(struct kvm *kvm, u64 *hu
 	/* Direct SPs do not require a shadowed_info_cache. */
 	caches.page_header_cache = &kvm->arch.split_page_header_cache;
 	caches.shadow_page_cache = &kvm->arch.split_shadow_page_cache;
-	caches.count_shadow_page_allocation = true;
 
 	/* Safe to pass NULL for vCPU since requesting a direct SP. */
 	return __kvm_mmu_get_shadow_page(kvm, NULL, &caches, gfn, role);
@@ -7101,10 +7097,9 @@ void kvm_mmu_pre_destroy_vm(struct kvm *kvm)
 		kthread_stop(kvm->arch.nx_huge_page_recovery_thread);
 }
 
-void *mmu_sp_memory_cache_alloc(struct kvm_mmu_memory_cache *shadow_page_cache,
-				bool count_allocation)
+void *mmu_sp_memory_cache_alloc(struct kvm_mmu_memory_cache *shadow_page_cache)
 {
-	if (count_allocation && shadow_page_cache->nobjs)
+	if (shadow_page_cache->nobjs)
 		percpu_counter_dec(&kvm_total_unused_cached_pages);
 	return kvm_mmu_memory_cache_alloc(shadow_page_cache);
 }
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 798cfbf0a36b..a607314348e3 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -338,7 +338,6 @@ void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);
 
 void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp);
 void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp);
-void *mmu_sp_memory_cache_alloc(struct kvm_mmu_memory_cache *cache,
-				bool count_allocation);
+void *mmu_sp_memory_cache_alloc(struct kvm_mmu_memory_cache *cache);
 
 #endif /* __KVM_X86_MMU_INTERNAL_H */
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index fa6eb1e9101e..d1e85012a008 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -265,8 +265,7 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp(struct kvm_vcpu *vcpu)
 	struct kvm_mmu_page *sp;
 
 	sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
-	sp->spt = mmu_sp_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache,
-					    true);
+	sp->spt = mmu_sp_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
 
 	return sp;
 }
-- 
2.40.0.rc0.216.gc4246ad0f0-goog