Merge tag 'nfs-for-4.8-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[cascardo/linux.git] / virt / kvm / arm / vgic / vgic-its.c
index 07411cf..4660a7d 100644 (file)
@@ -51,7 +51,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid)
 
        irq = kzalloc(sizeof(struct vgic_irq), GFP_KERNEL);
        if (!irq)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        INIT_LIST_HEAD(&irq->lpi_list);
        INIT_LIST_HEAD(&irq->ap_list);
@@ -441,39 +441,63 @@ static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm,
  * Find the target VCPU and the LPI number for a given devid/eventid pair
  * and make this IRQ pending, possibly injecting it.
  * Must be called with the its_lock mutex held.
+ * Returns 0 on success, a positive error value for any ITS mapping
+ * related errors and negative error values for generic errors.
  */
-static void vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
-                                u32 devid, u32 eventid)
+static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
+                               u32 devid, u32 eventid)
 {
+       struct kvm_vcpu *vcpu;
        struct its_itte *itte;
 
        if (!its->enabled)
-               return;
+               return -EBUSY;
 
        itte = find_itte(its, devid, eventid);
-       /* Triggering an unmapped IRQ gets silently dropped. */
-       if (itte && its_is_collection_mapped(itte->collection)) {
-               struct kvm_vcpu *vcpu;
-
-               vcpu = kvm_get_vcpu(kvm, itte->collection->target_addr);
-               if (vcpu && vcpu->arch.vgic_cpu.lpis_enabled) {
-                       spin_lock(&itte->irq->irq_lock);
-                       itte->irq->pending = true;
-                       vgic_queue_irq_unlock(kvm, itte->irq);
-               }
-       }
+       if (!itte || !its_is_collection_mapped(itte->collection))
+               return E_ITS_INT_UNMAPPED_INTERRUPT;
+
+       vcpu = kvm_get_vcpu(kvm, itte->collection->target_addr);
+       if (!vcpu)
+               return E_ITS_INT_UNMAPPED_INTERRUPT;
+
+       if (!vcpu->arch.vgic_cpu.lpis_enabled)
+               return -EBUSY;
+
+       spin_lock(&itte->irq->irq_lock);
+       itte->irq->pending = true;
+       vgic_queue_irq_unlock(kvm, itte->irq);
+
+       return 0;
+}
+
+static struct vgic_io_device *vgic_get_its_iodev(struct kvm_io_device *dev)
+{
+       struct vgic_io_device *iodev;
+
+       if (dev->ops != &kvm_io_gic_ops)
+               return NULL;
+
+       iodev = container_of(dev, struct vgic_io_device, dev);
+
+       if (iodev->iodev_type != IODEV_ITS)
+               return NULL;
+
+       return iodev;
 }
 
 /*
  * Queries the KVM IO bus framework to get the ITS pointer from the given
  * doorbell address.
  * We then call vgic_its_trigger_msi() with the decoded data.
+ * According to the KVM_SIGNAL_MSI API description returns 1 on success.
  */
 int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
 {
        u64 address;
        struct kvm_io_device *kvm_io_dev;
        struct vgic_io_device *iodev;
+       int ret;
 
        if (!vgic_has_its(kvm))
                return -ENODEV;
@@ -485,15 +509,28 @@ int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
 
        kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
        if (!kvm_io_dev)
-               return -ENODEV;
+               return -EINVAL;
 
-       iodev = container_of(kvm_io_dev, struct vgic_io_device, dev);
+       iodev = vgic_get_its_iodev(kvm_io_dev);
+       if (!iodev)
+               return -EINVAL;
 
        mutex_lock(&iodev->its->its_lock);
-       vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
+       ret = vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
        mutex_unlock(&iodev->its->its_lock);
 
-       return 0;
+       if (ret < 0)
+               return ret;
+
+       /*
+        * KVM_SIGNAL_MSI demands a return value > 0 for success and 0
+        * if the guest has blocked the MSI. So we map any LPI mapping
+        * related error to that.
+        */
+       if (ret)
+               return 0;
+       else
+               return 1;
 }
 
 /* Requires the its_lock to be held. */
@@ -502,7 +539,8 @@ static void its_free_itte(struct kvm *kvm, struct its_itte *itte)
        list_del(&itte->itte_list);
 
        /* This put matches the get in vgic_add_lpi. */
-       vgic_put_irq(kvm, itte->irq);
+       if (itte->irq)
+               vgic_put_irq(kvm, itte->irq);
 
        kfree(itte);
 }
@@ -697,6 +735,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
        struct its_device *device;
        struct its_collection *collection, *new_coll = NULL;
        int lpi_nr;
+       struct vgic_irq *irq;
 
        device = find_its_device(its, device_id);
        if (!device)
@@ -710,6 +749,10 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
            lpi_nr >= max_lpis_propbaser(kvm->arch.vgic.propbaser))
                return E_ITS_MAPTI_PHYSICALID_OOR;
 
+       /* If there is an existing mapping, behavior is UNPREDICTABLE. */
+       if (find_itte(its, device_id, event_id))
+               return 0;
+
        collection = find_collection(its, coll_id);
        if (!collection) {
                int ret = vgic_its_alloc_collection(its, &collection, coll_id);
@@ -718,22 +761,28 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
                new_coll = collection;
        }
 
-       itte = find_itte(its, device_id, event_id);
+       itte = kzalloc(sizeof(struct its_itte), GFP_KERNEL);
        if (!itte) {
-               itte = kzalloc(sizeof(struct its_itte), GFP_KERNEL);
-               if (!itte) {
-                       if (new_coll)
-                               vgic_its_free_collection(its, coll_id);
-                       return -ENOMEM;
-               }
-
-               itte->event_id  = event_id;
-               list_add_tail(&itte->itte_list, &device->itt_head);
+               if (new_coll)
+                       vgic_its_free_collection(its, coll_id);
+               return -ENOMEM;
        }
 
+       itte->event_id  = event_id;
+       list_add_tail(&itte->itte_list, &device->itt_head);
+
        itte->collection = collection;
        itte->lpi = lpi_nr;
-       itte->irq = vgic_add_lpi(kvm, lpi_nr);
+
+       irq = vgic_add_lpi(kvm, lpi_nr);
+       if (IS_ERR(irq)) {
+               if (new_coll)
+                       vgic_its_free_collection(its, coll_id);
+               its_free_itte(kvm, itte);
+               return PTR_ERR(irq);
+       }
+       itte->irq = irq;
+
        update_affinity_itte(kvm, itte);
 
        /*
@@ -981,9 +1030,7 @@ static int vgic_its_cmd_handle_int(struct kvm *kvm, struct vgic_its *its,
        u32 msi_data = its_cmd_get_id(its_cmd);
        u64 msi_devid = its_cmd_get_deviceid(its_cmd);
 
-       vgic_its_trigger_msi(kvm, its, msi_devid, msi_data);
-
-       return 0;
+       return vgic_its_trigger_msi(kvm, its, msi_devid, msi_data);
 }
 
 /*
@@ -1288,13 +1335,13 @@ void vgic_enable_lpis(struct kvm_vcpu *vcpu)
                its_sync_lpi_pending_table(vcpu);
 }
 
-static int vgic_its_init_its(struct kvm *kvm, struct vgic_its *its)
+static int vgic_register_its_iodev(struct kvm *kvm, struct vgic_its *its)
 {
        struct vgic_io_device *iodev = &its->iodev;
        int ret;
 
-       if (its->initialized)
-               return 0;
+       if (!its->initialized)
+               return -EBUSY;
 
        if (IS_VGIC_ADDR_UNDEF(its->vgic_its_base))
                return -ENXIO;
@@ -1311,9 +1358,6 @@ static int vgic_its_init_its(struct kvm *kvm, struct vgic_its *its)
                                      KVM_VGIC_V3_ITS_SIZE, &iodev->dev);
        mutex_unlock(&kvm->slots_lock);
 
-       if (!ret)
-               its->initialized = true;
-
        return ret;
 }
 
@@ -1435,9 +1479,6 @@ static int vgic_its_set_attr(struct kvm_device *dev,
                if (type != KVM_VGIC_ITS_ADDR_TYPE)
                        return -ENODEV;
 
-               if (its->initialized)
-                       return -EBUSY;
-
                if (copy_from_user(&addr, uaddr, sizeof(addr)))
                        return -EFAULT;
 
@@ -1453,7 +1494,9 @@ static int vgic_its_set_attr(struct kvm_device *dev,
        case KVM_DEV_ARM_VGIC_GRP_CTRL:
                switch (attr->attr) {
                case KVM_DEV_ARM_VGIC_CTRL_INIT:
-                       return vgic_its_init_its(dev->kvm, its);
+                       its->initialized = true;
+
+                       return 0;
                }
                break;
        }
@@ -1498,3 +1541,30 @@ int kvm_vgic_register_its_device(void)
        return kvm_register_device_ops(&kvm_arm_vgic_its_ops,
                                       KVM_DEV_TYPE_ARM_VGIC_ITS);
 }
+
+/*
+ * Registers all ITSes with the kvm_io_bus framework.
+ * To follow the existing VGIC initialization sequence, this has to be
+ * done as late as possible, just before the first VCPU runs.
+ */
+int vgic_register_its_iodevs(struct kvm *kvm)
+{
+       struct kvm_device *dev;
+       int ret = 0;
+
+       list_for_each_entry(dev, &kvm->devices, vm_node) {
+               if (dev->ops != &kvm_arm_vgic_its_ops)
+                       continue;
+
+               ret = vgic_register_its_iodev(kvm, dev->private);
+               if (ret)
+                       return ret;
+               /*
+                * We don't need to care about tearing down previously
+                * registered ITSes, as the kvm_io_bus framework removes
+                * them for us if the VM gets destroyed.
+                */
+       }
+
+       return ret;
+}