diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 98cd916..485bcdc 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -51,6 +51,12 @@
 #include "coalesced_mmio.h"
 #endif
 
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include "irq.h"
+#endif
+
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
 
@@ -71,6 +77,240 @@
 
 bool kvm_rebooting;
 
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
+						      int assigned_dev_id)
+{
+	struct list_head *ptr;
+	struct kvm_assigned_dev_kernel *match;
+
+	list_for_each(ptr, head) {
+		match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
+		if (match->assigned_dev_id == assigned_dev_id)
+			return match;
+	}
+	return NULL;
+}
+
+static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
+{
+	struct kvm_assigned_dev_kernel *assigned_dev;
+
+	assigned_dev = container_of(work, struct kvm_assigned_dev_kernel,
+				    interrupt_work);
+
+	/* This is taken to safely inject irq inside the guest. When
+	 * the interrupt injection (or the ioapic code) uses a
+	 * finer-grained lock, update this
+	 */
+	mutex_lock(&assigned_dev->kvm->lock);
+	kvm_set_irq(assigned_dev->kvm,
+		    assigned_dev->guest_irq, 1);
+	mutex_unlock(&assigned_dev->kvm->lock);
+	kvm_put_kvm(assigned_dev->kvm);
+}
+
+/* FIXME: Implement the OR logic needed to make shared interrupts on
+ * this line behave properly
+ */
+static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
+{
+	struct kvm_assigned_dev_kernel *assigned_dev =
+		(struct kvm_assigned_dev_kernel *) dev_id;
+
+	kvm_get_kvm(assigned_dev->kvm);
+	schedule_work(&assigned_dev->interrupt_work);
+	disable_irq_nosync(irq);
+	return IRQ_HANDLED;
+}
+
+/* Ack the irq line for an assigned device */
+static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
+{
+	struct kvm_assigned_dev_kernel *dev;
+
+	if (kian->gsi == -1)
+		return;
+
+	dev = container_of(kian, struct kvm_assigned_dev_kernel,
+			   ack_notifier);
+	kvm_set_irq(dev->kvm, dev->guest_irq, 0);
+	enable_irq(dev->host_irq);
+}
+
+static void kvm_free_assigned_device(struct kvm *kvm,
+				     struct kvm_assigned_dev_kernel
+				     *assigned_dev)
+{
+	if (irqchip_in_kernel(kvm) && assigned_dev->irq_requested)
+		free_irq(assigned_dev->host_irq, (void *)assigned_dev);
+
+	kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier);
+
+	if (cancel_work_sync(&assigned_dev->interrupt_work))
+		/* We had pending work. That means we will have to take
+		 * care of kvm_put_kvm.
+		 */
+		kvm_put_kvm(kvm);
+
+	pci_release_regions(assigned_dev->dev);
+	pci_disable_device(assigned_dev->dev);
+	pci_dev_put(assigned_dev->dev);
+
+	list_del(&assigned_dev->list);
+	kfree(assigned_dev);
+}
+
+void kvm_free_all_assigned_devices(struct kvm *kvm)
+{
+	struct list_head *ptr, *ptr2;
+	struct kvm_assigned_dev_kernel *assigned_dev;
+
+	list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) {
+		assigned_dev = list_entry(ptr,
+					  struct kvm_assigned_dev_kernel,
+					  list);
+
+		kvm_free_assigned_device(kvm, assigned_dev);
+	}
+}
+
+static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
+				   struct kvm_assigned_irq
+				   *assigned_irq)
+{
+	int r = 0;
+	struct kvm_assigned_dev_kernel *match;
+
+	mutex_lock(&kvm->lock);
+
+	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
+				      assigned_irq->assigned_dev_id);
+	if (!match) {
+		mutex_unlock(&kvm->lock);
+		return -EINVAL;
+	}
+
+	if (match->irq_requested) {
+		match->guest_irq = assigned_irq->guest_irq;
+		match->ack_notifier.gsi = assigned_irq->guest_irq;
+		mutex_unlock(&kvm->lock);
+		return 0;
+	}
+
+	INIT_WORK(&match->interrupt_work,
+		  kvm_assigned_dev_interrupt_work_handler);
+
+	if (irqchip_in_kernel(kvm)) {
+		if (!capable(CAP_SYS_RAWIO)) {
+			r = -EPERM;
+			goto out_release;
+		}
+
+		if (assigned_irq->host_irq)
+			match->host_irq = assigned_irq->host_irq;
+		else
+			match->host_irq = match->dev->irq;
+		match->guest_irq = assigned_irq->guest_irq;
+		match->ack_notifier.gsi = assigned_irq->guest_irq;
+		match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
+		kvm_register_irq_ack_notifier(kvm, &match->ack_notifier);
+
+		/* Even though this is PCI, we don't want to use shared
+		 * interrupts. Sharing host devices with guest-assigned devices
+		 * on the same interrupt line is not a happy situation: there
+		 * are going to be long delays in accepting, acking, etc.
+		 */
+		if (request_irq(match->host_irq, kvm_assigned_dev_intr, 0,
+				"kvm_assigned_device", (void *)match)) {
+			r = -EIO;
+			goto out_release;
+		}
+	}
+
+	match->irq_requested = true;
+	mutex_unlock(&kvm->lock);
+	return r;
+out_release:
+	mutex_unlock(&kvm->lock);
+	kvm_free_assigned_device(kvm, match);
+	return r;
+}
+
+static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
+				      struct kvm_assigned_pci_dev *assigned_dev)
+{
+	int r = 0;
+	struct kvm_assigned_dev_kernel *match;
+	struct pci_dev *dev;
+
+	mutex_lock(&kvm->lock);
+
+	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
+				      assigned_dev->assigned_dev_id);
+	if (match) {
+		/* device already assigned */
+		r = -EINVAL;
+		goto out;
+	}
+
+	match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL);
+	if (match == NULL) {
+		printk(KERN_INFO "%s: Couldn't allocate memory\n",
+		       __func__);
+		r = -ENOMEM;
+		goto out;
+	}
+	dev = pci_get_bus_and_slot(assigned_dev->busnr,
+				   assigned_dev->devfn);
+	if (!dev) {
+		printk(KERN_INFO "%s: host device not found\n", __func__);
+		r = -EINVAL;
+		goto out_free;
+	}
+	if (pci_enable_device(dev)) {
+		printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
+		r = -EBUSY;
+		goto out_put;
+	}
+	r = pci_request_regions(dev, "kvm_assigned_device");
+	if (r) {
+		printk(KERN_INFO "%s: Could not get access to device regions\n",
+		       __func__);
+		goto out_disable;
+	}
+	match->assigned_dev_id = assigned_dev->assigned_dev_id;
+	match->host_busnr = assigned_dev->busnr;
+	match->host_devfn = assigned_dev->devfn;
+	match->dev = dev;
+
+	match->kvm = kvm;
+
+	list_add(&match->list, &kvm->arch.assigned_dev_head);
+
+	if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) {
+		r = kvm_iommu_map_guest(kvm, match);
+		if (r)
+			goto out_list_del;
+	}
+
+out:
+	mutex_unlock(&kvm->lock);
+	return r;
+out_list_del:
+	list_del(&match->list);
+	pci_release_regions(dev);
+out_disable:
+	pci_disable_device(dev);
+out_put:
+	pci_dev_put(dev);
+out_free:
+	kfree(match);
+	mutex_unlock(&kvm->lock);
+	return r;
+}
+#endif
+
 static inline int valid_vcpu(int n)
 {
 	return likely(n >= 0 && n < KVM_MAX_VCPUS);
@@ -578,12 +818,12 @@
 	}
 
 	kvm_free_physmem_slot(&old, &new);
-
+#ifdef CONFIG_DMAR
 	/* map the pages in iommu page table */
 	r = kvm_iommu_map_pages(kvm, base_gfn, npages);
 	if (r)
 		goto out;
-
+#endif
 	return 0;
 
 out_free:
@@ -1383,6 +1623,30 @@
 		break;
 	}
 #endif
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+	case KVM_ASSIGN_PCI_DEVICE: {
+		struct kvm_assigned_pci_dev assigned_dev;
+
+		r = -EFAULT;
+		if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
+			goto out;
+		r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
+		if (r)
+			goto out;
+		break;
+	}
+	case KVM_ASSIGN_IRQ: {
+		struct kvm_assigned_irq assigned_irq;
+
+		r = -EFAULT;
+		if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
+			goto out;
+		r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
+		if (r)
+			goto out;
+		break;
+	}
+#endif
 	default:
 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
 	}