KVM: x86/mmu: Track the associated kmem_cache in the MMU caches

Track the kmem_cache used for non-page KVM MMU memory caches instead of
passing in the associated kmem_cache when filling the cache.  This will
allow consolidating code and other cleanups.

No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -251,6 +251,7 @@ struct kvm_kernel_irq_routing_entry;
  */
 struct kvm_mmu_memory_cache {
 	int nobjs;
+	struct kmem_cache *kmem_cache;
 	void *objects[KVM_NR_MEM_OBJS];
 };
 

arch/x86/kvm/mmu/mmu.c

@@ -1061,15 +1061,14 @@ static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu)
 	local_irq_enable();
 }
 
-static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
-				  struct kmem_cache *base_cache, int min)
+static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, int min)
 {
 	void *obj;
 
 	if (cache->nobjs >= min)
 		return 0;
 	while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
-		obj = kmem_cache_zalloc(base_cache, GFP_KERNEL_ACCOUNT);
+		obj = kmem_cache_zalloc(cache->kmem_cache, GFP_KERNEL_ACCOUNT);
 		if (!obj)
 			return cache->nobjs >= min ? 0 : -ENOMEM;
 		cache->objects[cache->nobjs++] = obj;
@@ -1082,11 +1081,10 @@ static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache *cache)
 	return cache->nobjs;
 }
 
-static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc,
-				  struct kmem_cache *cache)
+static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
 {
 	while (mc->nobjs)
-		kmem_cache_free(cache, mc->objects[--mc->nobjs]);
+		kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
 }
 
 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
@@ -1116,25 +1114,22 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 	int r;
 
 	r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache,
-				   pte_list_desc_cache, 8 + PTE_PREFETCH_NUM);
+				   8 + PTE_PREFETCH_NUM);
 	if (r)
 		goto out;
 	r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
 	if (r)
 		goto out;
-	r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
-				   mmu_page_header_cache, 4);
+	r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 4);
 out:
 	return r;
 }
 
 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
 {
-	mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache,
-				pte_list_desc_cache);
+	mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache);
 	mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
-	mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache,
-				mmu_page_header_cache);
+	mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
 }
 
 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
@@ -5705,6 +5700,9 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu)
 	uint i;
 	int ret;
 
+	vcpu->arch.mmu_pte_list_desc_cache.kmem_cache = pte_list_desc_cache;
+	vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache;
+
 	vcpu->arch.mmu = &vcpu->arch.root_mmu;
 	vcpu->arch.walk_mmu = &vcpu->arch.root_mmu;