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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 <avi@qumranet.com>
hifive-unleashed-5.1
Avi Kivity 2007-05-30 12:34:53 +03:00
parent 8d7282036f
commit d3d25b048b
3 changed files with 41 additions and 28 deletions
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4
drivers/kvm/kvm.h
View File

@ -299,12 +299,12 @@ struct kvm_vcpu {
struct vmx_msr_entry *guest_msrs;
struct vmx_msr_entry *host_msrs;
struct list_head free_pages;
struct kvm_mmu_page page_header_buf[KVM_NUM_MMU_PAGES];
struct kvm_mmu mmu;
struct kvm_mmu_memory_cache mmu_pte_chain_cache;
struct kvm_mmu_memory_cache mmu_rmap_desc_cache;
struct kvm_mmu_memory_cache mmu_page_cache;
struct kvm_mmu_memory_cache mmu_page_header_cache;
gfn_t last_pt_write_gfn;
int last_pt_write_count;

1
drivers/kvm/kvm_main.c
View File

@ -326,7 +326,6 @@ static struct kvm *kvm_create_vm(void)
vcpu->cpu = -1;
vcpu->kvm = kvm;
vcpu->mmu.root_hpa = INVALID_PAGE;
INIT_LIST_HEAD(&vcpu->free_pages);
spin_lock(&kvm_lock);
list_add(&kvm->vm_list, &vm_list);
spin_unlock(&kvm_lock);

64
drivers/kvm/mmu.c
View File

@ -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: