[PATCH] KVM: MMU: oom handling
When beginning to process a page fault, make sure we have enough shadow pages
available to service the fault. If not, free some pages.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 34c43bb..1d0be85 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -52,6 +52,8 @@
#define KVM_MAX_VCPUS 1
#define KVM_MEMORY_SLOTS 4
#define KVM_NUM_MMU_PAGES 256
+#define KVM_MIN_FREE_MMU_PAGES 5
+#define KVM_REFILL_PAGES 25
#define FX_IMAGE_SIZE 512
#define FX_IMAGE_ALIGN 16
@@ -278,6 +280,7 @@
* Hash table of struct kvm_mmu_page.
*/
struct list_head active_mmu_pages;
+ int n_free_mmu_pages;
struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES];
struct kvm_vcpu vcpus[KVM_MAX_VCPUS];
int memory_config_version;
@@ -451,6 +454,15 @@
void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
void kvm_mmu_post_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes);
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva);
+void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);
+
+static inline int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
+ u32 error_code)
+{
+ if (unlikely(vcpu->kvm->n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES))
+ kvm_mmu_free_some_pages(vcpu);
+ return vcpu->mmu.page_fault(vcpu, gva, error_code);
+}
static inline struct page *_gfn_to_page(struct kvm *kvm, gfn_t gfn)
{