From d3d25b048b9c7e5c1c20918157a71df734f71766 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 30 May 2007 12:34:53 +0300 Subject: KVM: MMU: Use slab caches for shadow pages and their headers Use slab caches instead of a simple custom list. Signed-off-by: Avi Kivity --- drivers/kvm/mmu.c | 64 +++++++++++++++++++++++++++++++++---------------------- 1 file changed, 39 insertions(+), 25 deletions(-) (limited to 'drivers/kvm/mmu.c') diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index c85c664..46491b4 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -165,6 +165,8 @@ struct kvm_rmap_desc { static struct kmem_cache *pte_chain_cache; static struct kmem_cache *rmap_desc_cache; +static struct kmem_cache *mmu_page_cache; +static struct kmem_cache *mmu_page_header_cache; static int is_write_protection(struct kvm_vcpu *vcpu) { @@ -235,6 +237,14 @@ static int __mmu_topup_memory_caches(struct kvm_vcpu *vcpu, gfp_t gfp_flags) goto out; r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache, rmap_desc_cache, 1, gfp_flags); + if (r) + goto out; + r = mmu_topup_memory_cache(&vcpu->mmu_page_cache, + mmu_page_cache, 4, gfp_flags); + if (r) + goto out; + r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache, + mmu_page_header_cache, 4, gfp_flags); out: return r; } @@ -258,6 +268,8 @@ static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) { mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache); mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache); + mmu_free_memory_cache(&vcpu->mmu_page_cache); + mmu_free_memory_cache(&vcpu->mmu_page_header_cache); } static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc, @@ -458,7 +470,9 @@ static void kvm_mmu_free_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page_head) { ASSERT(is_empty_shadow_page(page_head->spt)); - list_move(&page_head->link, &vcpu->free_pages); + list_del(&page_head->link); + mmu_memory_cache_free(&vcpu->mmu_page_cache, page_head->spt); + mmu_memory_cache_free(&vcpu->mmu_page_header_cache, page_head); ++vcpu->kvm->n_free_mmu_pages; } @@ -472,11 +486,14 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, { struct kvm_mmu_page *page; - if (list_empty(&vcpu->free_pages)) + if (!vcpu->kvm->n_free_mmu_pages) return NULL; - page = list_entry(vcpu->free_pages.next, struct kvm_mmu_page, link); - list_move(&page->link, &vcpu->kvm->active_mmu_pages); + page = mmu_memory_cache_alloc(&vcpu->mmu_page_header_cache, + sizeof *page); + page->spt = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE); + set_page_private(virt_to_page(page->spt), (unsigned long)page); + list_add(&page->link, &vcpu->kvm->active_mmu_pages); ASSERT(is_empty_shadow_page(page->spt)); page->slot_bitmap = 0; page->multimapped = 0; @@ -1083,6 +1100,7 @@ static int init_kvm_mmu(struct kvm_vcpu *vcpu) ASSERT(vcpu); ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa)); + mmu_topup_memory_caches(vcpu); if (!is_paging(vcpu)) return nonpaging_init_context(vcpu); else if (is_long_mode(vcpu)) @@ -1256,13 +1274,6 @@ static void free_mmu_pages(struct kvm_vcpu *vcpu) struct kvm_mmu_page, link); kvm_mmu_zap_page(vcpu, page); } - while (!list_empty(&vcpu->free_pages)) { - page = list_entry(vcpu->free_pages.next, - struct kvm_mmu_page, link); - list_del(&page->link); - free_page((unsigned long)page->spt); - page->spt = NULL; - } free_page((unsigned long)vcpu->mmu.pae_root); } @@ -1273,18 +1284,7 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu) ASSERT(vcpu); - for (i = 0; i < KVM_NUM_MMU_PAGES; i++) { - struct kvm_mmu_page *page_header = &vcpu->page_header_buf[i]; - - INIT_LIST_HEAD(&page_header->link); - if ((page = alloc_page(GFP_KERNEL)) == NULL) - goto error_1; - set_page_private(page, (unsigned long)page_header); - page_header->spt = page_address(page); - memset(page_header->spt, 0, PAGE_SIZE); - list_add(&page_header->link, &vcpu->free_pages); - ++vcpu->kvm->n_free_mmu_pages; - } + vcpu->kvm->n_free_mmu_pages = KVM_NUM_MMU_PAGES; /* * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64. @@ -1309,7 +1309,6 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu) { ASSERT(vcpu); ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa)); - ASSERT(list_empty(&vcpu->free_pages)); return alloc_mmu_pages(vcpu); } @@ -1318,7 +1317,6 @@ int kvm_mmu_setup(struct kvm_vcpu *vcpu) { ASSERT(vcpu); ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa)); - ASSERT(!list_empty(&vcpu->free_pages)); return init_kvm_mmu(vcpu); } @@ -1377,6 +1375,10 @@ void kvm_mmu_module_exit(void) kmem_cache_destroy(pte_chain_cache); if (rmap_desc_cache) kmem_cache_destroy(rmap_desc_cache); + if (mmu_page_cache) + kmem_cache_destroy(mmu_page_cache); + if (mmu_page_header_cache) + kmem_cache_destroy(mmu_page_header_cache); } int kvm_mmu_module_init(void) @@ -1392,6 +1394,18 @@ int kvm_mmu_module_init(void) if (!rmap_desc_cache) goto nomem; + mmu_page_cache = kmem_cache_create("kvm_mmu_page", + PAGE_SIZE, + PAGE_SIZE, 0, NULL, NULL); + if (!mmu_page_cache) + goto nomem; + + mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", + sizeof(struct kvm_mmu_page), + 0, 0, NULL, NULL); + if (!mmu_page_header_cache) + goto nomem; + return 0; nomem: -- cgit v1.1