Allocate shadow pages from slab instead of page-allocator, frequent shadow page allocation and free can be hit in the slab cache, it is very useful for shadow mmu
Signed-off-by: Xiao Guangrong <[email protected]> --- arch/x86/include/asm/kvm_host.h | 3 ++- arch/x86/kvm/mmu.c | 46 ++++++++++++++++++++++++++++++++++------- 2 files changed, 41 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 5cbf316..df9ae10 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -389,6 +389,7 @@ 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_shadow_page_cache; struct kvm_mmu_memory_cache mmu_page_cache; struct kvm_mmu_memory_cache mmu_page_header_cache; @@ -946,7 +947,7 @@ static inline struct kvm_mmu_page *page_header(hpa_t shadow_page) { struct page *page = pfn_to_page(shadow_page >> PAGE_SHIFT); - return (struct kvm_mmu_page *)page_private(page); + return (struct kvm_mmu_page *)(page->mapping); } static inline u16 kvm_read_ldt(void) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index f3ae74e6..1bcc8c8 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -178,6 +178,7 @@ struct kvm_shadow_walk_iterator { __shadow_walk_next(&(_walker), spte)) static struct kmem_cache *pte_list_desc_cache; +static struct kmem_cache *mmu_shadow_page_cache; static struct kmem_cache *mmu_page_header_cache; static struct percpu_counter kvm_total_used_mmu_pages; @@ -746,7 +747,14 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) GFP_KERNEL); if (r) goto out; - r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8); + + r = mmu_topup_memory_cache(&vcpu->arch.mmu_shadow_page_cache, + mmu_shadow_page_cache, 4, + GFP_KERNEL); + if (r) + goto out; + + r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 4); if (r) goto out; r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, @@ -760,6 +768,8 @@ 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_shadow_page_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); @@ -1675,12 +1685,28 @@ static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr) percpu_counter_add(&kvm_total_used_mmu_pages, nr); } +static void set_page_header(struct kvm_mmu_page *sp) +{ + struct page *page = virt_to_page(sp->spt); + + WARN_ON(page->mapping); + page->mapping = (struct address_space *)sp; +} + +static void clear_page_header(struct kvm_mmu_page *sp) +{ + struct page *page = virt_to_page(sp->spt); + + page->mapping = NULL; +} + static void kvm_mmu_free_page(struct kvm_mmu_page *sp) { ASSERT(is_empty_shadow_page(sp->spt)); hlist_del(&sp->hash_link); list_del(&sp->link); - free_page((unsigned long)sp->spt); + clear_page_header(sp); + kmem_cache_free(mmu_shadow_page_cache, sp->spt); if (!sp->role.direct) free_page((unsigned long)sp->gfns); kmem_cache_free(mmu_page_header_cache, sp); @@ -1719,10 +1745,10 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, 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); - set_page_private(virt_to_page(sp->spt), (unsigned long)sp); + set_page_header(sp); /* * The active_mmu_pages list is the FIFO list, do not move the @@ -2046,12 +2072,13 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu, } } -static void init_shadow_page_table(struct kvm_mmu_page *sp) +static void init_shadow_page_table(void *p) { + u64 *sptp = (u64 *)p; int i; for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - sp->spt[i] = 0ull; + sptp[i] = 0ull; } static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) @@ -2137,7 +2164,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, account_shadowed(vcpu->kvm, gfn); } sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; - init_shadow_page_table(sp); trace_kvm_mmu_get_page(sp, true); return sp; } @@ -4683,6 +4709,12 @@ int kvm_mmu_module_init(void) if (!pte_list_desc_cache) goto nomem; + mmu_shadow_page_cache = kmem_cache_create("mmu_shadow_page_cache", + PAGE_SIZE, PAGE_SIZE, 0, + init_shadow_page_table); + if (!mmu_shadow_page_cache) + goto nomem; + mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", sizeof(struct kvm_mmu_page), 0, 0, NULL); -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
