Re: [PATCH 02/21] KVM: x86/mmu: Consolidate "page" variant of memory cache helpers

Ben Gardon
2020-06-09T22:54:25Z

On Fri, Jun 5, 2020 at 2:39 PM Sean Christopherson
<sean.j.christopherson@intel.com> wrote:
>
> Drop the "page" variants of the topup/free memory cache helpers, using
> the existence of an associated kmem_cache to select the correct alloc
> or free routine.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Reviewed-by: Ben Gardon <bgardon@google.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 37 +++++++++++--------------------------
> 1 file changed, 11 insertions(+), 26 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 0830c195c9ed..cbc101663a89 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -1067,7 +1067,10 @@ static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, int min)
> if (cache->nobjs >= min)
> return 0;
> while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
> - obj = kmem_cache_zalloc(cache->kmem_cache, GFP_KERNEL_ACCOUNT);
> + if (cache->kmem_cache)
> + obj = kmem_cache_zalloc(cache->kmem_cache, GFP_KERNEL_ACCOUNT);
> + else
> + obj = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
> if (!obj)
> return cache->nobjs >= min ? 0 : -ENOMEM;
> cache->objects[cache->nobjs++] = obj;
> @@ -1082,30 +1085,12 @@ static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache *cache)
>
> static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
> {
> - while (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,
> - int min)
> -{
> - void *page;
> -
> - if (cache->nobjs >= min)
> - return 0;
> - while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
> - page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
> - if (!page)
> - return cache->nobjs >= min ? 0 : -ENOMEM;
> - cache->objects[cache->nobjs++] = page;
> + while (mc->nobjs) {
> + if (mc->kmem_cache)
> + kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
> + else
> + free_page((unsigned long)mc->objects[--mc->nobjs]);
> }
> - return 0;
> -}
> -
> -static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
> -{
> - while (mc->nobjs)
> - free_page((unsigned long)mc->objects[--mc->nobjs]);
> }
>
> static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
> @@ -1116,7 +1101,7 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
> 8 + PTE_PREFETCH_NUM);
> if (r)
> goto out;
> - r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
> + r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_cache, 8);
> if (r)
> goto out;
> r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 4);
> @@ -1127,7 +1112,7 @@ 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_page(&vcpu->arch.mmu_page_cache);
> + mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
> mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
> }
>
> --
> 2.26.0
>