diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt
index baa8fde..f3d1c2a 100644
--- a/Documentation/kvm/api.txt
+++ b/Documentation/kvm/api.txt
@@ -848,6 +848,29 @@ function properly, this is the place to put them.
        __u8  pad[64];
 };
 
+4.37 KVM_SWITCH_DIRTY_LOG (vm ioctl)
+
+Capability: basic
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_dirty_log (in/out)
+Returns: 0 on success, -1 on error
+
+/* for KVM_SWITCH_DIRTY_LOG */
+struct kvm_dirty_log {
+	__u32 slot;
+	__u32 padding;
+	union {
+		void __user *dirty_bitmap; /* one bit per page */
+		__u64 addr;
+	};
+};
+
+Given a memory slot, return the address of a bitmap containing any
+pages dirtied since the last call to this ioctl.  Bit 0 is the first
+page in the memory slot.  Ensure the entire structure is cleared to
+avoid padding issues.
+
 5. The kvm_run structure
 
 Application code obtains a pointer to the kvm_run structure by
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index c3f0b70..04fbb1c 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1843,8 +1843,8 @@ out:
 	return r;
 }
 
-int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
-		struct kvm_dirty_log *log)
+static int kvm_ia64_update_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
+				     bool need_copy)
 {
 	int r;
 	unsigned long n;
@@ -1857,7 +1857,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	if (r)
 		goto out;
 
-	r = kvm_get_dirty_log(kvm, log);
+	r = kvm_update_dirty_log(kvm, log, need_copy);
 	if (r)
 		goto out;
 
@@ -1865,10 +1865,9 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	/* If nothing is dirty, don't bother messing with page tables. */
 	if (memslot->is_dirty) {
 		kvm_flush_remote_tlbs(kvm);
-		n = kvm_dirty_bitmap_bytes(memslot);
-		clear_user(memslot->dirty_bitmap, n);
 		memslot->is_dirty = false;
 	}
+
 	r = 0;
 out:
 	mutex_unlock(&kvm->slots_lock);
@@ -1876,6 +1875,16 @@ out:
 	return r;
 }
 
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return kvm_ia64_update_dirty_log(kvm, log, true);
+}
+
+int kvm_vm_ioctl_switch_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return kvm_ia64_update_dirty_log(kvm, log, false);
+}
+
 int kvm_arch_hardware_setup(void)
 {
 	return 0;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index b074e19..d813dca 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1112,8 +1112,9 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 /*
  * Get (and clear) the dirty memory log for a memory slot.
  */
-int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
-				      struct kvm_dirty_log *log)
+static int kvmppc_update_dirty_log(struct kvm *kvm,
+				   struct kvm_dirty_log *log,
+				   bool need_copy)
 {
 	struct kvm_memory_slot *memslot;
 	struct kvm_vcpu *vcpu;
@@ -1123,7 +1124,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 
 	mutex_lock(&kvm->slots_lock);
 
-	r = kvm_get_dirty_log(kvm, log);
+	r = kvm_update_dirty_log(kvm, log, need_copy);
 	if (r)
 		goto out;
 
@@ -1136,8 +1137,6 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 		kvm_for_each_vcpu(n, vcpu, kvm)
 			kvmppc_mmu_pte_pflush(vcpu, ga, ga_end);
 
-		n = kvm_dirty_bitmap_bytes(memslot);
-		clear_user(memslot->dirty_bitmap, n);
 		memslot->is_dirty = false;
 	}
 
@@ -1147,6 +1146,16 @@ out:
 	return r;
 }
 
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return kvmppc_update_dirty_log(kvm, log, true);
+}
+
+int kvm_vm_ioctl_switch_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return kvmppc_update_dirty_log(kvm, log, false);
+}
+
 int kvmppc_core_check_processor_compat(void)
 {
 	return 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ad55353..45b728c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2718,11 +2718,9 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm,
 	return 0;
 }
 
-/*
- * Get (and clear) the dirty memory log for a memory slot.
- */
-int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
-				      struct kvm_dirty_log *log)
+static int kvm_x86_update_dirty_log(struct kvm *kvm,
+				    struct kvm_dirty_log *log,
+				    bool need_copy)
 {
 	int r;
 	struct kvm_memory_slot *memslot;
@@ -2773,12 +2771,34 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 		dirty_bitmap_old = dirty_bitmap;
 	}
 
-	r = kvm_copy_dirty_bitmap(log->dirty_bitmap, dirty_bitmap_old, n);
+	if (need_copy) {
+		r = kvm_copy_dirty_bitmap(log->dirty_bitmap,
+					  dirty_bitmap_old, n);
+	} else {
+		log->addr = (unsigned long)dirty_bitmap_old;
+		r = 0;
+	}
 out:
 	mutex_unlock(&kvm->slots_lock);
 	return r;
 }
 
+/*
+ * Get (and clear) the dirty memory log for a memory slot.
+ */
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return kvm_x86_update_dirty_log(kvm, log, true);
+}
+
+/*
+ * Switch to the next dirty bitmap and return the address of the old one.
+ */
+int kvm_vm_ioctl_switch_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return kvm_x86_update_dirty_log(kvm, log, false);
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 23ea022..9fa6f1e 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -12,7 +12,7 @@
 #include <linux/ioctl.h>
 #include <asm/kvm.h>
 
-#define KVM_API_VERSION 12
+#define KVM_API_VERSION 13
 
 /* *** Deprecated interfaces *** */
 
@@ -318,7 +318,7 @@ struct kvm_dirty_log {
 	__u32 padding1;
 	union {
 		void __user *dirty_bitmap; /* one bit per page */
-		__u64 padding2;
+		__u64 addr;
 	};
 };
 
@@ -524,6 +524,7 @@ struct kvm_enable_cap {
 #define KVM_CAP_PPC_OSI 52
 #define KVM_CAP_PPC_UNSET_IRQ 53
 #define KVM_CAP_ENABLE_CAP 54
+#define KVM_CAP_USER_DIRTY_BITMAP 55
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -620,6 +621,7 @@ struct kvm_clock_data {
 					struct kvm_userspace_memory_region)
 #define KVM_SET_TSS_ADDR          _IO(KVMIO,   0x47)
 #define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO,  0x48, __u64)
+#define KVM_SWITCH_DIRTY_LOG      _IOW(KVMIO,  0x49, struct kvm_dirty_log)
 /* Device model IOC */
 #define KVM_CREATE_IRQCHIP        _IO(KVMIO,   0x60)
 #define KVM_IRQ_LINE              _IOW(KVMIO,  0x61, struct kvm_irq_level)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d4d217a..addecee 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -334,9 +334,10 @@ int kvm_dev_ioctl_check_extension(long ext);
 int kvm_copy_dirty_bitmap(unsigned long __user *to,
 			  const unsigned long __user *from,
 			  unsigned long bytes);
-int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
-int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
-				struct kvm_dirty_log *log);
+int kvm_update_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
+			 bool need_copy);
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
+int kvm_vm_ioctl_switch_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
 
 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 				   struct
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9323639..cba133d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -844,7 +844,8 @@ out_fault:
 #endif
 }
 
-int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+int kvm_update_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
+			 bool need_copy)
 {
 	struct kvm_memory_slot *memslot;
 	int r;
@@ -861,9 +862,23 @@ int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 
 	n = kvm_dirty_bitmap_bytes(memslot);
 
-	r = -EFAULT;
-	if (kvm_copy_dirty_bitmap(log->dirty_bitmap, memslot->dirty_bitmap, n))
-		goto out;
+	if (need_copy) {
+		r = -EFAULT;
+		if (kvm_copy_dirty_bitmap(log->dirty_bitmap,
+					  memslot->dirty_bitmap, n))
+			goto out;
+
+		if (memslot->is_dirty)
+			clear_user(memslot->dirty_bitmap, n);
+	} else {
+		unsigned long __user *dirty_bitmap;
+
+		dirty_bitmap = memslot->dirty_bitmap;
+		clear_user(memslot->dirty_bitmap_old, n);
+		memslot->dirty_bitmap = memslot->dirty_bitmap_old;
+		memslot->dirty_bitmap_old = dirty_bitmap;
+		log->addr = (unsigned long)dirty_bitmap;
+	}
 
 	r = 0;
 out:
@@ -1699,6 +1714,21 @@ static long kvm_vm_ioctl(struct file *filp,
 			goto out;
 		break;
 	}
+	case KVM_SWITCH_DIRTY_LOG: {
+		struct kvm_dirty_log log;
+
+		r = -EFAULT;
+		if (copy_from_user(&log, argp, sizeof log))
+			goto out;
+		r = kvm_vm_ioctl_switch_dirty_log(kvm, &log);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user(argp, &log, sizeof log))
+			goto out;
+		r = 0;
+		break;
+	}
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 	case KVM_REGISTER_COALESCED_MMIO: {
 		struct kvm_coalesced_mmio_zone zone;
@@ -1790,7 +1820,7 @@ static long kvm_vm_compat_ioctl(struct file *filp,
 			goto out;
 		log.slot	 = compat_log.slot;
 		log.padding1	 = compat_log.padding1;
-		log.padding2	 = compat_log.padding2;
+		log.addr	 = compat_log.padding2;
 		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
 
 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
@@ -1879,6 +1909,7 @@ static long kvm_dev_ioctl_check_extension_generic(long arg)
 	case KVM_CAP_SET_BOOT_CPU_ID:
 #endif
 	case KVM_CAP_INTERNAL_ERROR_DATA:
+	case KVM_CAP_USER_DIRTY_BITMAP:
 		return 1;
 #ifdef CONFIG_HAVE_KVM_IRQCHIP
 	case KVM_CAP_IRQ_ROUTING:
