From 67052b3508f09956427d6476fd35e8fddde6c618 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Sun, 15 May 2011 23:27:08 +0800 Subject: [PATCH] KVM: MMU: remove the arithmetic of parent pte rmap Parent pte rmap and page rmap are very similar, so use the same arithmetic for them Signed-off-by: Xiao Guangrong Signed-off-by: Marcelo Tosatti --- arch/x86/include/asm/kvm_host.h | 7 +- arch/x86/kvm/mmu.c | 189 ++++++++++------------------------------ 2 files changed, 46 insertions(+), 150 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e6a4a57..ff17deb 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -227,14 +227,10 @@ struct kvm_mmu_page { * in this shadow page. */ DECLARE_BITMAP(slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); - bool multimapped; /* More than one parent_pte? */ bool unsync; int root_count; /* Currently serving as active root */ unsigned int unsync_children; - union { - u64 *parent_pte; /* !multimapped */ - struct hlist_head parent_ptes; /* multimapped, kvm_pte_chain */ - }; + unsigned long parent_ptes; /* Reverse mapping for parent_pte */ DECLARE_BITMAP(unsync_child_bitmap, 512); }; @@ -346,7 +342,6 @@ struct kvm_vcpu_arch { * put it here to avoid allocation */ struct kvm_pv_mmu_op_buffer mmu_op_buffer; - struct kvm_mmu_memory_cache mmu_pte_chain_cache; struct kvm_mmu_memory_cache mmu_pte_list_desc_cache; struct kvm_mmu_memory_cache mmu_page_cache; struct kvm_mmu_memory_cache mmu_page_header_cache; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a6811cb..9eaca1c 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -182,9 +182,6 @@ struct kvm_shadow_walk_iterator { shadow_walk_okay(&(_walker)); \ shadow_walk_next(&(_walker))) -typedef void (*mmu_parent_walk_fn) (struct kvm_mmu_page *sp, u64 *spte); - -static struct kmem_cache *pte_chain_cache; static struct kmem_cache *pte_list_desc_cache; static struct kmem_cache *mmu_page_header_cache; static struct percpu_counter kvm_total_used_mmu_pages; @@ -397,12 +394,8 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) { int r; - r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache, - pte_chain_cache, 4); - if (r) - goto out; r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, - pte_list_desc_cache, 4 + PTE_PREFETCH_NUM); + pte_list_desc_cache, 8 + PTE_PREFETCH_NUM); if (r) goto out; r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8); @@ -416,8 +409,6 @@ out: static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) { - mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache, - pte_chain_cache); mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache, pte_list_desc_cache); mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache); @@ -435,17 +426,6 @@ static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc, return p; } -static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu) -{ - return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache, - sizeof(struct kvm_pte_chain)); -} - -static void mmu_free_pte_chain(struct kvm_pte_chain *pc) -{ - kmem_cache_free(pte_chain_cache, pc); -} - static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu) { return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache, @@ -721,6 +701,26 @@ static void pte_list_remove(u64 *spte, unsigned long *pte_list) } } +typedef void (*pte_list_walk_fn) (u64 *spte); +static void pte_list_walk(unsigned long *pte_list, pte_list_walk_fn fn) +{ + struct pte_list_desc *desc; + int i; + + if (!*pte_list) + return; + + if (!(*pte_list & 1)) + return fn((u64 *)*pte_list); + + desc = (struct pte_list_desc *)(*pte_list & ~1ul); + while (desc) { + for (i = 0; i < PTE_LIST_EXT && desc->sptes[i]; ++i) + fn(desc->sptes[i]); + desc = desc->more; + } +} + /* * Take gfn and return the reverse mapping to it. */ @@ -1069,134 +1069,52 @@ static unsigned kvm_page_table_hashfn(gfn_t gfn) return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1); } -static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, - u64 *parent_pte, int direct) -{ - struct kvm_mmu_page *sp; - - sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp); - sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE); - if (!direct) - sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, - PAGE_SIZE); - set_page_private(virt_to_page(sp->spt), (unsigned long)sp); - list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); - bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); - sp->multimapped = 0; - sp->parent_pte = parent_pte; - kvm_mod_used_mmu_pages(vcpu->kvm, +1); - return sp; -} - static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, u64 *parent_pte) { - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - int i; - if (!parent_pte) return; - if (!sp->multimapped) { - u64 *old = sp->parent_pte; - if (!old) { - sp->parent_pte = parent_pte; - return; - } - sp->multimapped = 1; - pte_chain = mmu_alloc_pte_chain(vcpu); - INIT_HLIST_HEAD(&sp->parent_ptes); - hlist_add_head(&pte_chain->link, &sp->parent_ptes); - pte_chain->parent_ptes[0] = old; - } - hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) { - if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1]) - continue; - for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) - if (!pte_chain->parent_ptes[i]) { - pte_chain->parent_ptes[i] = parent_pte; - return; - } - } - pte_chain = mmu_alloc_pte_chain(vcpu); - BUG_ON(!pte_chain); - hlist_add_head(&pte_chain->link, &sp->parent_ptes); - pte_chain->parent_ptes[0] = parent_pte; + pte_list_add(vcpu, parent_pte, &sp->parent_ptes); } static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, u64 *parent_pte) { - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - int i; - - if (!sp->multimapped) { - BUG_ON(sp->parent_pte != parent_pte); - sp->parent_pte = NULL; - return; - } - hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) - for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { - if (!pte_chain->parent_ptes[i]) - break; - if (pte_chain->parent_ptes[i] != parent_pte) - continue; - while (i + 1 < NR_PTE_CHAIN_ENTRIES - && pte_chain->parent_ptes[i + 1]) { - pte_chain->parent_ptes[i] - = pte_chain->parent_ptes[i + 1]; - ++i; - } - pte_chain->parent_ptes[i] = NULL; - if (i == 0) { - hlist_del(&pte_chain->link); - mmu_free_pte_chain(pte_chain); - if (hlist_empty(&sp->parent_ptes)) { - sp->multimapped = 0; - sp->parent_pte = NULL; - } - } - return; - } - BUG(); + pte_list_remove(parent_pte, &sp->parent_ptes); } -static void mmu_parent_walk(struct kvm_mmu_page *sp, mmu_parent_walk_fn fn) +static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, + u64 *parent_pte, int direct) { - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - struct kvm_mmu_page *parent_sp; - int i; - - if (!sp->multimapped && sp->parent_pte) { - parent_sp = page_header(__pa(sp->parent_pte)); - fn(parent_sp, sp->parent_pte); - return; - } - - hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) - for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { - u64 *spte = pte_chain->parent_ptes[i]; - - if (!spte) - break; - parent_sp = page_header(__pa(spte)); - fn(parent_sp, spte); - } + struct kvm_mmu_page *sp; + sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, + sizeof *sp); + sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE); + if (!direct) + sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, + PAGE_SIZE); + set_page_private(virt_to_page(sp->spt), (unsigned long)sp); + list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); + bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); + sp->parent_ptes = 0; + mmu_page_add_parent_pte(vcpu, sp, parent_pte); + kvm_mod_used_mmu_pages(vcpu->kvm, +1); + return sp; } -static void mark_unsync(struct kvm_mmu_page *sp, u64 *spte); +static void mark_unsync(u64 *spte); static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) { - mmu_parent_walk(sp, mark_unsync); + pte_list_walk(&sp->parent_ptes, mark_unsync); } -static void mark_unsync(struct kvm_mmu_page *sp, u64 *spte) +static void mark_unsync(u64 *spte) { + struct kvm_mmu_page *sp; unsigned int index; + sp = page_header(__pa(spte)); index = spte - sp->spt; if (__test_and_set_bit(index, sp->unsync_child_bitmap)) return; @@ -1694,17 +1612,7 @@ static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) { u64 *parent_pte; - while (sp->multimapped || sp->parent_pte) { - if (!sp->multimapped) - parent_pte = sp->parent_pte; - else { - struct kvm_pte_chain *chain; - - chain = container_of(sp->parent_ptes.first, - struct kvm_pte_chain, link); - parent_pte = chain->parent_ptes[0]; - } - BUG_ON(!parent_pte); + while ((parent_pte = pte_list_next(&sp->parent_ptes, NULL))) { kvm_mmu_put_page(sp, parent_pte); __set_spte(parent_pte, shadow_trap_nonpresent_pte); } @@ -3617,8 +3525,6 @@ static struct shrinker mmu_shrinker = { static void mmu_destroy_caches(void) { - if (pte_chain_cache) - kmem_cache_destroy(pte_chain_cache); if (pte_list_desc_cache) kmem_cache_destroy(pte_list_desc_cache); if (mmu_page_header_cache) @@ -3627,11 +3533,6 @@ static void mmu_destroy_caches(void) int kvm_mmu_module_init(void) { - pte_chain_cache = kmem_cache_create("kvm_pte_chain", - sizeof(struct kvm_pte_chain), - 0, 0, NULL); - if (!pte_chain_cache) - goto nomem; pte_list_desc_cache = kmem_cache_create("pte_list_desc", sizeof(struct pte_list_desc), 0, 0, NULL); -- 2.7.4