Merge tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio

Pull vfio update from Alex Williamson:
 - convert to misc driver to support module auto loading
 - remove unnecessary and dangerous use of device_lock

* tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio:
  vfio-pci: Don't use device_lock around AER interrupt setup
  vfio: Convert control interface to misc driver
  misc: Reserve minor for VFIO

3 files changed, 37 insertions, 54 deletions

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 2319d206f630..7ba042498857 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -872,9 +872,13 @@ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
                 return PCI_ERS_RESULT_DISCONNECT;
         }
 
+        mutex_lock(&vdev->igate);
+
         if (vdev->err_trigger)
                 eventfd_signal(vdev->err_trigger, 1);
 
+        mutex_unlock(&vdev->igate);
+
         vfio_device_put(device);
 
         return PCI_ERS_RESULT_CAN_RECOVER;
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 641bc87bdb96..210357691dc0 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -749,54 +749,37 @@ static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
                                     unsigned count, uint32_t flags, void *data)
 {
         int32_t fd = *(int32_t *)data;
-        struct pci_dev *pdev = vdev->pdev;
 
         if ((index != VFIO_PCI_ERR_IRQ_INDEX) ||
             !(flags & VFIO_IRQ_SET_DATA_TYPE_MASK))
                 return -EINVAL;
 
-        /*
-         * device_lock synchronizes setting and checking of
-         * err_trigger. The vfio_pci_aer_err_detected() is also
-         * called with device_lock held.
-         */
-
         /* DATA_NONE/DATA_BOOL enables loopback testing */
-
         if (flags & VFIO_IRQ_SET_DATA_NONE) {
-                device_lock(&pdev->dev);
                 if (vdev->err_trigger)
                         eventfd_signal(vdev->err_trigger, 1);
-                device_unlock(&pdev->dev);
                 return 0;
         } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
                 uint8_t trigger = *(uint8_t *)data;
-                device_lock(&pdev->dev);
                 if (trigger && vdev->err_trigger)
                         eventfd_signal(vdev->err_trigger, 1);
-                device_unlock(&pdev->dev);
                 return 0;
         }
 
         /* Handle SET_DATA_EVENTFD */
-
         if (fd == -1) {
-                device_lock(&pdev->dev);
                 if (vdev->err_trigger)
                         eventfd_ctx_put(vdev->err_trigger);
                 vdev->err_trigger = NULL;
-                device_unlock(&pdev->dev);
                 return 0;
         } else if (fd >= 0) {
                 struct eventfd_ctx *efdctx;
                 efdctx = eventfd_ctx_fdget(fd);
                 if (IS_ERR(efdctx))
                         return PTR_ERR(efdctx);
-                device_lock(&pdev->dev);
                 if (vdev->err_trigger)
                         eventfd_ctx_put(vdev->err_trigger);
                 vdev->err_trigger = efdctx;
-                device_unlock(&pdev->dev);
                 return 0;
         } else
                 return -EINVAL;
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 1eab4ace0671..21271d8df023 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -22,6 +22,7 @@
 #include <linux/idr.h>
 #include <linux/iommu.h>
 #include <linux/list.h>
+#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
@@ -45,9 +46,7 @@ static struct vfio {
         struct idr                      group_idr;
         struct mutex                    group_lock;
         struct cdev                     group_cdev;
-        struct device                   *dev;
-        dev_t                           devt;
-        struct cdev                     cdev;
+        dev_t                           group_devt;
         wait_queue_head_t               release_q;
 } vfio;
 
@@ -142,8 +141,7 @@ EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver);
  */
 static int vfio_alloc_group_minor(struct vfio_group *group)
 {
-        /* index 0 is used by /dev/vfio/vfio */
-        return idr_alloc(&vfio.group_idr, group, 1, MINORMASK + 1, GFP_KERNEL);
+        return idr_alloc(&vfio.group_idr, group, 0, MINORMASK + 1, GFP_KERNEL);
 }
 
 static void vfio_free_group_minor(int minor)
@@ -243,7 +241,8 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
                 }
         }
 
-        dev = device_create(vfio.class, NULL, MKDEV(MAJOR(vfio.devt), minor),
+        dev = device_create(vfio.class, NULL,
+                            MKDEV(MAJOR(vfio.group_devt), minor),
                             group, "%d", iommu_group_id(iommu_group));
         if (IS_ERR(dev)) {
                 vfio_free_group_minor(minor);
@@ -268,7 +267,7 @@ static void vfio_group_release(struct kref *kref)
 
         WARN_ON(!list_empty(&group->device_list));
 
-        device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor));
+        device_destroy(vfio.class, MKDEV(MAJOR(vfio.group_devt), group->minor));
         list_del(&group->vfio_next);
         vfio_free_group_minor(group->minor);
         vfio_group_unlock_and_free(group);
@@ -1419,12 +1418,17 @@ EXPORT_SYMBOL_GPL(vfio_external_user_iommu_id);
  */
 static char *vfio_devnode(struct device *dev, umode_t *mode)
 {
-        if (mode && (MINOR(dev->devt) == 0))
-                *mode = S_IRUGO | S_IWUGO;
-
         return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
 }
 
+static struct miscdevice vfio_dev = {
+        .minor = VFIO_MINOR,
+        .name = "vfio",
+        .fops = &vfio_fops,
+        .nodename = "vfio/vfio",
+        .mode = S_IRUGO | S_IWUGO,
+};
+
 static int __init vfio_init(void)
 {
         int ret;
@@ -1436,6 +1440,13 @@ static int __init vfio_init(void)
         INIT_LIST_HEAD(&vfio.iommu_drivers_list);
         init_waitqueue_head(&vfio.release_q);
 
+        ret = misc_register(&vfio_dev);
+        if (ret) {
+                pr_err("vfio: misc device register failed\n");
+                return ret;
+        }
+
+        /* /dev/vfio/$GROUP */
         vfio.class = class_create(THIS_MODULE, "vfio");
         if (IS_ERR(vfio.class)) {
                 ret = PTR_ERR(vfio.class);
@@ -1444,27 +1455,14 @@ static int __init vfio_init(void)
 
         vfio.class->devnode = vfio_devnode;
 
-        ret = alloc_chrdev_region(&vfio.devt, 0, MINORMASK, "vfio");
-        if (ret)
-                goto err_base_chrdev;
-
-        cdev_init(&vfio.cdev, &vfio_fops);
-        ret = cdev_add(&vfio.cdev, vfio.devt, 1);
+        ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK, "vfio");
         if (ret)
-                goto err_base_cdev;
+                goto err_alloc_chrdev;
 
-        vfio.dev = device_create(vfio.class, NULL, vfio.devt, NULL, "vfio");
-        if (IS_ERR(vfio.dev)) {
-                ret = PTR_ERR(vfio.dev);
-                goto err_base_dev;
-        }
-
-        /* /dev/vfio/$GROUP */
         cdev_init(&vfio.group_cdev, &vfio_group_fops);
-        ret = cdev_add(&vfio.group_cdev,
-                       MKDEV(MAJOR(vfio.devt), 1), MINORMASK - 1);
+        ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK);
         if (ret)
-                goto err_groups_cdev;
+                goto err_cdev_add;
 
         pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 
@@ -1478,16 +1476,13 @@ static int __init vfio_init(void)
 
         return 0;
 
-err_groups_cdev:
-        device_destroy(vfio.class, vfio.devt);
-err_base_dev:
-        cdev_del(&vfio.cdev);
-err_base_cdev:
-        unregister_chrdev_region(vfio.devt, MINORMASK);
-err_base_chrdev:
+err_cdev_add:
+        unregister_chrdev_region(vfio.group_devt, MINORMASK);
+err_alloc_chrdev:
         class_destroy(vfio.class);
         vfio.class = NULL;
 err_class:
+        misc_deregister(&vfio_dev);
         return ret;
 }
 
@@ -1497,11 +1492,10 @@ static void __exit vfio_cleanup(void)
 
         idr_destroy(&vfio.group_idr);
         cdev_del(&vfio.group_cdev);
-        device_destroy(vfio.class, vfio.devt);
-        cdev_del(&vfio.cdev);
-        unregister_chrdev_region(vfio.devt, MINORMASK);
+        unregister_chrdev_region(vfio.group_devt, MINORMASK);
         class_destroy(vfio.class);
         vfio.class = NULL;
+        misc_deregister(&vfio_dev);
 }
 
 module_init(vfio_init);
@@ -1511,3 +1505,5 @@ MODULE_VERSION(DRIVER_VERSION);
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_ALIAS_MISCDEV(VFIO_MINOR);
+MODULE_ALIAS("devname:vfio/vfio");