[PATCH] KVM: MMU: oom handling

[linux-block.git] / drivers / kvm / mmu.c

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 7e20dbf4f84cf7e1644f8234a287ac3f6fb7627f..e4a20a45d834414cc904341819e5397b3db1a254 100644 (file)
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -310,6 +310,7 @@ static void kvm_mmu_free_page(struct kvm_vcpu *vcpu, hpa_t page_hpa)
        list_del(&page_head->link);
        page_head->page_hpa = page_hpa;
        list_add(&page_head->link, &vcpu->free_pages);
+       ++vcpu->kvm->n_free_mmu_pages;
 }
 
 static int is_empty_shadow_page(hpa_t page_hpa)
@@ -344,6 +345,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
        page->global = 1;
        page->multimapped = 0;
        page->parent_pte = parent_pte;
+       --vcpu->kvm->n_free_mmu_pages;
        return page;
 }
 
@@ -521,10 +523,6 @@ static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
                             u64 *parent_pte)
 {
        mmu_page_remove_parent_pte(page, parent_pte);
-       kvm_mmu_page_unlink_children(vcpu, page);
-       hlist_del(&page->hash_link);
-       list_del(&page->link);
-       list_add(&page->link, &vcpu->free_pages);
 }
 
 static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
@@ -546,6 +544,9 @@ static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
                kvm_mmu_put_page(vcpu, page, parent_pte);
                *parent_pte = 0;
        }
+       kvm_mmu_page_unlink_children(vcpu, page);
+       hlist_del(&page->hash_link);
+       kvm_mmu_free_page(vcpu, page->page_hpa);
 }
 
 static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
@@ -743,18 +744,6 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
        vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
 }
 
-static void nonpaging_flush(struct kvm_vcpu *vcpu)
-{
-       hpa_t root = vcpu->mmu.root_hpa;
-
-       ++kvm_stat.tlb_flush;
-       pgprintk("nonpaging_flush\n");
-       mmu_free_roots(vcpu);
-       mmu_alloc_roots(vcpu);
-       kvm_arch_ops->set_cr3(vcpu, root);
-       kvm_arch_ops->tlb_flush(vcpu);
-}
-
 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
 {
        return vaddr;
@@ -763,28 +752,19 @@ static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
                               u32 error_code)
 {
-       int ret;
        gpa_t addr = gva;
+       hpa_t paddr;
 
        ASSERT(vcpu);
        ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
 
-       for (;;) {
-            hpa_t paddr;
 
-            paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
+       paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
 
-            if (is_error_hpa(paddr))
-                    return 1;
+       if (is_error_hpa(paddr))
+               return 1;
 
-            ret = nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
-            if (ret) {
-                    nonpaging_flush(vcpu);
-                    continue;
-            }
-            break;
-       }
-       return ret;
+       return nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
 }
 
 static void nonpaging_inval_page(struct kvm_vcpu *vcpu, gva_t addr)
@@ -1093,6 +1073,18 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
        return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT);
 }
 
+void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
+{
+       while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) {
+               struct kvm_mmu_page *page;
+
+               page = container_of(vcpu->kvm->active_mmu_pages.prev,
+                                   struct kvm_mmu_page, link);
+               kvm_mmu_zap_page(vcpu, page);
+       }
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages);
+
 static void free_mmu_pages(struct kvm_vcpu *vcpu)
 {
        while (!list_empty(&vcpu->free_pages)) {
@@ -1124,6 +1116,7 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
                page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT;
                memset(__va(page_header->page_hpa), 0, PAGE_SIZE);
                list_add(&page_header->link, &vcpu->free_pages);
+               ++vcpu->kvm->n_free_mmu_pages;
        }
 
        /*