KVM: x86/mmu: Separate the memory caches for shadow pages and gfn arrays

Use separate caches for allocating shadow pages versus gfn arrays.  This
sets the stage for specifying __GFP_ZERO when allocating shadow pages
without incurring extra cost for gfn arrays.

No functional change intended.

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-10-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6b4efe1c15ad293141783d3834474defe3a53e99..01f5c15088519a13ddb0575adff72005249123e0 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -602,7 +602,8 @@ struct kvm_vcpu_arch {
        struct kvm_mmu *walk_mmu;
 
        struct kvm_mmu_memory_cache mmu_pte_list_desc_cache;
-       struct kvm_mmu_memory_cache mmu_page_cache;
+       struct kvm_mmu_memory_cache mmu_shadow_page_cache;
+       struct kvm_mmu_memory_cache mmu_gfn_array_cache;
        struct kvm_mmu_memory_cache mmu_page_header_cache;
 
        /*

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index be6ca862531faf4184b4946aa4104011d54b251d..a8fc17ac7ed0b4f614f7be111bf58c9a7e886b12 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1109,8 +1109,12 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
                                   1 + PT64_ROOT_MAX_LEVEL + PTE_PREFETCH_NUM);
        if (r)
                return r;
-       r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_cache,
-                                  2 * PT64_ROOT_MAX_LEVEL);
+       r = mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache,
+                                  PT64_ROOT_MAX_LEVEL);
+       if (r)
+               return r;
+       r = mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache,
+                                  PT64_ROOT_MAX_LEVEL);
        if (r)
                return r;
        return mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
@@ -1120,7 +1124,8 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
 {
        mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache);
-       mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
+       mmu_free_memory_cache(&vcpu->arch.mmu_shadow_page_cache);
+       mmu_free_memory_cache(&vcpu->arch.mmu_gfn_array_cache);
        mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
 }
 
@@ -2082,9 +2087,9 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct
        struct kvm_mmu_page *sp;
 
        sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
-       sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache);
+       sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
        if (!direct)
-               sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache);
+               sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache);
        set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 
        /*