#include <linux/pagemap.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
+#include <linux/bitops.h>
 
 #include <asm/processor.h>
 #include <asm/io.h>
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
 
-static int msi2intx = 1;
-module_param(msi2intx, bool, 0);
-
 DEFINE_SPINLOCK(kvm_lock);
 LIST_HEAD(vm_list);
 
         * finer-grained lock, update this
         */
        mutex_lock(&kvm->lock);
-       if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_MSIX) {
+       if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
                struct kvm_guest_msix_entry *guest_entries =
                        assigned_dev->guest_msix_entries;
                for (i = 0; i < assigned_dev->entries_nr; i++) {
                kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
                            assigned_dev->guest_irq, 1);
                if (assigned_dev->irq_requested_type &
-                               KVM_ASSIGNED_DEV_GUEST_MSI) {
+                               KVM_DEV_IRQ_GUEST_MSI) {
                        enable_irq(assigned_dev->host_irq);
                        assigned_dev->host_irq_disabled = false;
                }
        struct kvm_assigned_dev_kernel *assigned_dev =
                (struct kvm_assigned_dev_kernel *) dev_id;
 
-       if (assigned_dev->irq_requested_type == KVM_ASSIGNED_DEV_MSIX) {
+       if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
                int index = find_index_from_host_irq(assigned_dev, irq);
                if (index < 0)
                        return IRQ_HANDLED;
        }
 }
 
-/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
-static void kvm_free_assigned_irq(struct kvm *kvm,
-                                 struct kvm_assigned_dev_kernel *assigned_dev)
+static void deassign_guest_irq(struct kvm *kvm,
+                              struct kvm_assigned_dev_kernel *assigned_dev)
 {
-       if (!irqchip_in_kernel(kvm))
-               return;
-
        kvm_unregister_irq_ack_notifier(&assigned_dev->ack_notifier);
+       assigned_dev->ack_notifier.gsi = -1;
 
        if (assigned_dev->irq_source_id != -1)
                kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
        assigned_dev->irq_source_id = -1;
+       assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_GUEST_MASK);
+}
 
-       if (!assigned_dev->irq_requested_type)
-               return;
-
+/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
+static void deassign_host_irq(struct kvm *kvm,
+                             struct kvm_assigned_dev_kernel *assigned_dev)
+{
        /*
         * In kvm_free_device_irq, cancel_work_sync return true if:
         * 1. work is scheduled, and then cancelled.
         * now, the kvm state is still legal for probably we also have to wait
         * interrupt_work done.
         */
-       if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_MSIX) {
+       if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
                int i;
                for (i = 0; i < assigned_dev->entries_nr; i++)
                        disable_irq_nosync(assigned_dev->
 
                free_irq(assigned_dev->host_irq, (void *)assigned_dev);
 
-               if (assigned_dev->irq_requested_type &
-                               KVM_ASSIGNED_DEV_HOST_MSI)
+               if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSI)
                        pci_disable_msi(assigned_dev->dev);
        }
 
-       assigned_dev->irq_requested_type = 0;
+       assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_HOST_MASK);
+}
+
+static int kvm_deassign_irq(struct kvm *kvm,
+                           struct kvm_assigned_dev_kernel *assigned_dev,
+                           unsigned long irq_requested_type)
+{
+       unsigned long guest_irq_type, host_irq_type;
+
+       if (!irqchip_in_kernel(kvm))
+               return -EINVAL;
+       /* no irq assignment to deassign */
+       if (!assigned_dev->irq_requested_type)
+               return -ENXIO;
+
+       host_irq_type = irq_requested_type & KVM_DEV_IRQ_HOST_MASK;
+       guest_irq_type = irq_requested_type & KVM_DEV_IRQ_GUEST_MASK;
+
+       if (host_irq_type)
+               deassign_host_irq(kvm, assigned_dev);
+       if (guest_irq_type)
+               deassign_guest_irq(kvm, assigned_dev);
+
+       return 0;
 }
 
+static void kvm_free_assigned_irq(struct kvm *kvm,
+                                 struct kvm_assigned_dev_kernel *assigned_dev)
+{
+       kvm_deassign_irq(kvm, assigned_dev, assigned_dev->irq_requested_type);
+}
 
 static void kvm_free_assigned_device(struct kvm *kvm,
                                     struct kvm_assigned_dev_kernel
        }
 }
 
-static int assigned_device_update_intx(struct kvm *kvm,
-                       struct kvm_assigned_dev_kernel *adev,
-                       struct kvm_assigned_irq *airq)
+static int assigned_device_enable_host_intx(struct kvm *kvm,
+                                           struct kvm_assigned_dev_kernel *dev)
 {
-       adev->guest_irq = airq->guest_irq;
-       adev->ack_notifier.gsi = airq->guest_irq;
-
-       if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_INTX)
-               return 0;
-
-       if (irqchip_in_kernel(kvm)) {
-               if (!msi2intx &&
-                   (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)) {
-                       free_irq(adev->host_irq, (void *)adev);
-                       pci_disable_msi(adev->dev);
-               }
+       dev->host_irq = dev->dev->irq;
+       /* 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(dev->host_irq, kvm_assigned_dev_intr,
+                       0, "kvm_assigned_intx_device", (void *)dev))
+               return -EIO;
+       return 0;
+}
 
-               if (!capable(CAP_SYS_RAWIO))
-                       return -EPERM;
+#ifdef __KVM_HAVE_MSI
+static int assigned_device_enable_host_msi(struct kvm *kvm,
+                                          struct kvm_assigned_dev_kernel *dev)
+{
+       int r;
 
-               if (airq->host_irq)
-                       adev->host_irq = airq->host_irq;
-               else
-                       adev->host_irq = adev->dev->irq;
+       if (!dev->dev->msi_enabled) {
+               r = pci_enable_msi(dev->dev);
+               if (r)
+                       return r;
+       }
 
-               /* 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(adev->host_irq, kvm_assigned_dev_intr,
-                               0, "kvm_assigned_intx_device", (void *)adev))
-                       return -EIO;
+       dev->host_irq = dev->dev->irq;
+       if (request_irq(dev->host_irq, kvm_assigned_dev_intr, 0,
+                       "kvm_assigned_msi_device", (void *)dev)) {
+               pci_disable_msi(dev->dev);
+               return -EIO;
        }
 
-       adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_INTX |
-                                  KVM_ASSIGNED_DEV_HOST_INTX;
        return 0;
 }
+#endif
 
-#ifdef CONFIG_X86
-static int assigned_device_update_msi(struct kvm *kvm,
-                       struct kvm_assigned_dev_kernel *adev,
-                       struct kvm_assigned_irq *airq)
+#ifdef __KVM_HAVE_MSIX
+static int assigned_device_enable_host_msix(struct kvm *kvm,
+                                           struct kvm_assigned_dev_kernel *dev)
 {
-       int r;
+       int i, r = -EINVAL;
 
-       adev->guest_irq = airq->guest_irq;
-       if (airq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {
-               /* x86 don't care upper address of guest msi message addr */
-               adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_MSI;
-               adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_INTX;
-               adev->ack_notifier.gsi = -1;
-       } else if (msi2intx) {
-               adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_INTX;
-               adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_MSI;
-               adev->ack_notifier.gsi = airq->guest_irq;
-       } else {
-               /*
-                * Guest require to disable device MSI, we disable MSI and
-                * re-enable INTx by default again. Notice it's only for
-                * non-msi2intx.
-                */
-               assigned_device_update_intx(kvm, adev, airq);
-               return 0;
-       }
+       /* host_msix_entries and guest_msix_entries should have been
+        * initialized */
+       if (dev->entries_nr == 0)
+               return r;
 
-       if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
-               return 0;
+       r = pci_enable_msix(dev->dev, dev->host_msix_entries, dev->entries_nr);
+       if (r)
+               return r;
 
-       if (irqchip_in_kernel(kvm)) {
-               if (!msi2intx) {
-                       if (adev->irq_requested_type &
-                                       KVM_ASSIGNED_DEV_HOST_INTX)
-                               free_irq(adev->host_irq, (void *)adev);
+       for (i = 0; i < dev->entries_nr; i++) {
+               r = request_irq(dev->host_msix_entries[i].vector,
+                               kvm_assigned_dev_intr, 0,
+                               "kvm_assigned_msix_device",
+                               (void *)dev);
+               /* FIXME: free requested_irq's on failure */
+               if (r)
+                       return r;
+       }
 
-                       r = pci_enable_msi(adev->dev);
-                       if (r)
-                               return r;
-               }
+       return 0;
+}
 
-               adev->host_irq = adev->dev->irq;
-               if (request_irq(adev->host_irq, kvm_assigned_dev_intr, 0,
-                               "kvm_assigned_msi_device", (void *)adev))
-                       return -EIO;
-       }
+#endif
 
-       if (!msi2intx)
-               adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI;
+static int assigned_device_enable_guest_intx(struct kvm *kvm,
+                               struct kvm_assigned_dev_kernel *dev,
+                               struct kvm_assigned_irq *irq)
+{
+       dev->guest_irq = irq->guest_irq;
+       dev->ack_notifier.gsi = irq->guest_irq;
+       return 0;
+}
 
-       adev->irq_requested_type |= KVM_ASSIGNED_DEV_HOST_MSI;
+#ifdef __KVM_HAVE_MSI
+static int assigned_device_enable_guest_msi(struct kvm *kvm,
+                       struct kvm_assigned_dev_kernel *dev,
+                       struct kvm_assigned_irq *irq)
+{
+       dev->guest_irq = irq->guest_irq;
+       dev->ack_notifier.gsi = -1;
        return 0;
 }
 #endif
+#ifdef __KVM_HAVE_MSIX
+static int assigned_device_enable_guest_msix(struct kvm *kvm,
+                       struct kvm_assigned_dev_kernel *dev,
+                       struct kvm_assigned_irq *irq)
+{
+       dev->guest_irq = irq->guest_irq;
+       dev->ack_notifier.gsi = -1;
+       return 0;
+}
+#endif
+
+static int assign_host_irq(struct kvm *kvm,
+                          struct kvm_assigned_dev_kernel *dev,
+                          __u32 host_irq_type)
+{
+       int r = -EEXIST;
+
+       if (dev->irq_requested_type & KVM_DEV_IRQ_HOST_MASK)
+               return r;
 
+       switch (host_irq_type) {
+       case KVM_DEV_IRQ_HOST_INTX:
+               r = assigned_device_enable_host_intx(kvm, dev);
+               break;
+#ifdef __KVM_HAVE_MSI
+       case KVM_DEV_IRQ_HOST_MSI:
+               r = assigned_device_enable_host_msi(kvm, dev);
+               break;
+#endif
 #ifdef __KVM_HAVE_MSIX
-static int assigned_device_update_msix(struct kvm *kvm,
-                       struct kvm_assigned_dev_kernel *adev,
-                       struct kvm_assigned_irq *airq)
-{
-       /* TODO Deal with KVM_DEV_IRQ_ASSIGNED_MASK_MSIX */
-       int i, r;
-
-       adev->ack_notifier.gsi = -1;
-
-       if (irqchip_in_kernel(kvm)) {
-               if (airq->flags & KVM_DEV_IRQ_ASSIGN_MASK_MSIX)
-                       return -ENOTTY;
-
-               if (!(airq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSIX)) {
-                       /* Guest disable MSI-X */
-                       kvm_free_assigned_irq(kvm, adev);
-                       if (msi2intx) {
-                               pci_enable_msi(adev->dev);
-                               if (adev->dev->msi_enabled)
-                                       return assigned_device_update_msi(kvm,
-                                                       adev, airq);
-                       }
-                       return assigned_device_update_intx(kvm, adev, airq);
-               }
+       case KVM_DEV_IRQ_HOST_MSIX:
+               r = assigned_device_enable_host_msix(kvm, dev);
+               break;
+#endif
+       default:
+               r = -EINVAL;
+       }
 
-               /* host_msix_entries and guest_msix_entries should have been
-                * initialized */
-               if (adev->entries_nr == 0)
-                       return -EINVAL;
+       if (!r)
+               dev->irq_requested_type |= host_irq_type;
 
-               kvm_free_assigned_irq(kvm, adev);
+       return r;
+}
 
-               r = pci_enable_msix(adev->dev, adev->host_msix_entries,
-                                   adev->entries_nr);
-               if (r)
-                       return r;
+static int assign_guest_irq(struct kvm *kvm,
+                           struct kvm_assigned_dev_kernel *dev,
+                           struct kvm_assigned_irq *irq,
+                           unsigned long guest_irq_type)
+{
+       int id;
+       int r = -EEXIST;
 
-               for (i = 0; i < adev->entries_nr; i++) {
-                       r = request_irq((adev->host_msix_entries + i)->vector,
-                                       kvm_assigned_dev_intr, 0,
-                                       "kvm_assigned_msix_device",
-                                       (void *)adev);
-                       if (r)
-                               return r;
-               }
+       if (dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MASK)
+               return r;
+
+       id = kvm_request_irq_source_id(kvm);
+       if (id < 0)
+               return id;
+
+       dev->irq_source_id = id;
+
+       switch (guest_irq_type) {
+       case KVM_DEV_IRQ_GUEST_INTX:
+               r = assigned_device_enable_guest_intx(kvm, dev, irq);
+               break;
+#ifdef __KVM_HAVE_MSI
+       case KVM_DEV_IRQ_GUEST_MSI:
+               r = assigned_device_enable_guest_msi(kvm, dev, irq);
+               break;
+#endif
+#ifdef __KVM_HAVE_MSIX
+       case KVM_DEV_IRQ_GUEST_MSIX:
+               r = assigned_device_enable_guest_msix(kvm, dev, irq);
+               break;
+#endif
+       default:
+               r = -EINVAL;
        }
 
-       adev->irq_requested_type |= KVM_ASSIGNED_DEV_MSIX;
+       if (!r) {
+               dev->irq_requested_type |= guest_irq_type;
+               kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
+       } else
+               kvm_free_irq_source_id(kvm, dev->irq_source_id);
 
-       return 0;
+       return r;
 }
-#endif
 
+/* TODO Deal with KVM_DEV_IRQ_ASSIGNED_MASK_MSIX */
 static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
-                                  struct kvm_assigned_irq
-                                  *assigned_irq)
+                                  struct kvm_assigned_irq *assigned_irq)
 {
-       int r = 0;
+       int r = -EINVAL;
        struct kvm_assigned_dev_kernel *match;
-       u32 current_flags = 0, changed_flags;
+       unsigned long host_irq_type, guest_irq_type;
 
-       mutex_lock(&kvm->lock);
+       if (!capable(CAP_SYS_RAWIO))
+               return -EPERM;
 
+       if (!irqchip_in_kernel(kvm))
+               return r;
+
+       mutex_lock(&kvm->lock);
+       r = -ENODEV;
        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_type) {
-               INIT_WORK(&match->interrupt_work,
-                               kvm_assigned_dev_interrupt_work_handler);
-               if (irqchip_in_kernel(kvm)) {
-                       /* Register ack nofitier */
-                       match->ack_notifier.gsi = -1;
-                       match->ack_notifier.irq_acked =
-                                       kvm_assigned_dev_ack_irq;
-                       kvm_register_irq_ack_notifier(kvm,
-                                       &match->ack_notifier);
-
-                       /* Request IRQ source ID */
-                       r = kvm_request_irq_source_id(kvm);
-                       if (r < 0)
-                               goto out_release;
-                       else
-                               match->irq_source_id = r;
-
-#ifdef CONFIG_X86
-                       /* Determine host device irq type, we can know the
-                        * result from dev->msi_enabled */
-                       if (msi2intx)
-                               pci_enable_msi(match->dev);
-#endif
-               }
-       }
+       if (!match)
+               goto out;
 
-       if (match->irq_requested_type & KVM_ASSIGNED_DEV_MSIX)
-               current_flags |= KVM_DEV_IRQ_ASSIGN_ENABLE_MSIX;
-       else if ((match->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) &&
-                (match->irq_requested_type & KVM_ASSIGNED_DEV_GUEST_MSI))
-               current_flags |= KVM_DEV_IRQ_ASSIGN_ENABLE_MSI;
+       host_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_HOST_MASK);
+       guest_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_GUEST_MASK);
 
-       changed_flags = assigned_irq->flags ^ current_flags;
+       r = -EINVAL;
+       /* can only assign one type at a time */
+       if (hweight_long(host_irq_type) > 1)
+               goto out;
+       if (hweight_long(guest_irq_type) > 1)
+               goto out;
+       if (host_irq_type == 0 && guest_irq_type == 0)
+               goto out;
 
-#ifdef __KVM_HAVE_MSIX
-       if (changed_flags & KVM_DEV_IRQ_ASSIGN_MSIX_ACTION) {
-               r = assigned_device_update_msix(kvm, match, assigned_irq);
-               if (r) {
-                       printk(KERN_WARNING "kvm: failed to execute "
-                                       "MSI-X action!\n");
-                       goto out_release;
-               }
-       } else
-#endif
-       if ((changed_flags & KVM_DEV_IRQ_ASSIGN_MSI_ACTION) ||
-           (msi2intx && match->dev->msi_enabled)) {
-#ifdef CONFIG_X86
-               r = assigned_device_update_msi(kvm, match, assigned_irq);
-               if (r) {
-                       printk(KERN_WARNING "kvm: failed to enable "
-                                       "MSI device!\n");
-                       goto out_release;
-               }
-#else
-               r = -ENOTTY;
-#endif
-       } else if (assigned_irq->host_irq == 0 && match->dev->irq == 0) {
-               /* Host device IRQ 0 means don't support INTx */
-               if (!msi2intx) {
-                       printk(KERN_WARNING
-                              "kvm: wait device to enable MSI!\n");
-                       r = 0;
-               } else {
-                       printk(KERN_WARNING
-                              "kvm: failed to enable MSI device!\n");
-                       r = -ENOTTY;
-                       goto out_release;
-               }
-       } else {
-               /* Non-sharing INTx mode */
-               r = assigned_device_update_intx(kvm, match, assigned_irq);
-               if (r) {
-                       printk(KERN_WARNING "kvm: failed to enable "
-                                       "INTx device!\n");
-                       goto out_release;
-               }
-       }
+       r = 0;
+       if (host_irq_type)
+               r = assign_host_irq(kvm, match, host_irq_type);
+       if (r)
+               goto out;
 
+       if (guest_irq_type)
+               r = assign_guest_irq(kvm, match, assigned_irq, guest_irq_type);
+out:
        mutex_unlock(&kvm->lock);
        return r;
-out_release:
+}
+
+static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
+                                        struct kvm_assigned_irq
+                                        *assigned_irq)
+{
+       int r = -ENODEV;
+       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)
+               goto out;
+
+       r = kvm_deassign_irq(kvm, match, assigned_irq->flags);
+out:
        mutex_unlock(&kvm->lock);
-       kvm_free_assigned_device(kvm, match);
        return r;
 }
 
                                      assigned_dev->assigned_dev_id);
        if (match) {
                /* device already assigned */
-               r = -EINVAL;
+               r = -EEXIST;
                goto out;
        }
 
        match->dev = dev;
        match->irq_source_id = -1;
        match->kvm = kvm;
+       match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
+       INIT_WORK(&match->interrupt_work,
+                 kvm_assigned_dev_interrupt_work_handler);
 
        list_add(&match->list, &kvm->arch.assigned_dev_head);
 
                break;
        }
        case KVM_ASSIGN_IRQ: {
+               r = -EOPNOTSUPP;
+               break;
+       }
+#ifdef KVM_CAP_ASSIGN_DEV_IRQ
+       case KVM_ASSIGN_DEV_IRQ: {
                struct kvm_assigned_irq assigned_irq;
 
                r = -EFAULT;
                        goto out;
                break;
        }
+       case KVM_DEASSIGN_DEV_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_deassign_dev_irq(kvm, &assigned_irq);
+               if (r)
+                       goto out;
+               break;
+       }
+#endif
 #endif
 #ifdef KVM_CAP_DEVICE_DEASSIGNMENT
        case KVM_DEASSIGN_PCI_DEVICE: {
 
        kvm_preempt_ops.sched_in = kvm_sched_in;
        kvm_preempt_ops.sched_out = kvm_sched_out;
-#ifndef CONFIG_X86
-       msi2intx = 0;
-#endif
 
        return 0;