diff mbox series

[07/14] vfio: simplify iommu group allocation for mediated devices

Message ID 20210811151500.2744-8-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/14] vfio: Move vfio_iommu_group_get() to vfio_register_group_dev() | expand

Commit Message

Christoph Hellwig Aug. 11, 2021, 3:14 p.m. UTC 
Reuse the logic in vfio_noiommu_group_alloc to allocate a single-device
iommu group for mediated device.  For this a new
vfio_register_mediated_dev is added that calls vfio_noiommu_group_alloc.
The noiommu boolean in struct vfio_group is replaced with a set of flags
to that mediated devices can be distinguished from noiommu devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/vfio/mdev/mdev_driver.c | 46 ++---------------------
 drivers/vfio/mdev/vfio_mdev.c   |  2 +-
 drivers/vfio/vfio.c             | 66 ++++++++++++++++++++-------------
 include/linux/vfio.h            |  1 +
 samples/vfio-mdev/mbochs.c      |  2 +-
 samples/vfio-mdev/mdpy.c        |  2 +-
 samples/vfio-mdev/mtty.c        |  2 +-
 7 files changed, 49 insertions(+), 72 deletions(-)
diff mbox series

Patch

diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index c368ec824e2b5c..14b9ab17426838 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -13,61 +13,23 @@ 
 
 #include "mdev_private.h"
 
-static int mdev_attach_iommu(struct mdev_device *mdev)
-{
-	int ret;
-	struct iommu_group *group;
-
-	group = iommu_group_alloc();
-	if (IS_ERR(group))
-		return PTR_ERR(group);
-
-	ret = iommu_group_add_device(group, &mdev->dev);
-	if (!ret)
-		dev_info(&mdev->dev, "MDEV: group_id = %d\n",
-			 iommu_group_id(group));
-
-	iommu_group_put(group);
-	return ret;
-}
-
-static void mdev_detach_iommu(struct mdev_device *mdev)
-{
-	iommu_group_remove_device(&mdev->dev);
-	dev_info(&mdev->dev, "MDEV: detaching iommu\n");
-}
-
 static int mdev_probe(struct device *dev)
 {
 	struct mdev_driver *drv =
 		container_of(dev->driver, struct mdev_driver, driver);
-	struct mdev_device *mdev = to_mdev_device(dev);
-	int ret;
-
-	ret = mdev_attach_iommu(mdev);
-	if (ret)
-		return ret;
 
-	if (drv->probe) {
-		ret = drv->probe(mdev);
-		if (ret)
-			mdev_detach_iommu(mdev);
-	}
-
-	return ret;
+	if (!drv->probe)
+		return 0;
+	return drv->probe(to_mdev_device(dev));
 }
 
 static int mdev_remove(struct device *dev)
 {
 	struct mdev_driver *drv =
 		container_of(dev->driver, struct mdev_driver, driver);
-	struct mdev_device *mdev = to_mdev_device(dev);
 
 	if (drv->remove)
-		drv->remove(mdev);
-
-	mdev_detach_iommu(mdev);
-
+		drv->remove(to_mdev_device(dev));
 	return 0;
 }
 
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index 7a9883048216e7..7bab075173145b 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -119,7 +119,7 @@  static int vfio_mdev_probe(struct mdev_device *mdev)
 		return -ENOMEM;
 
 	vfio_init_group_dev(vdev, &mdev->dev, &vfio_mdev_dev_ops);
-	ret = vfio_register_group_dev(vdev);
+	ret = vfio_register_mediated_dev(vdev);
 	if (ret)
 		goto out_uninit;
 
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 964e53c483baac..8d225038b04802 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -67,6 +67,9 @@  struct vfio_unbound_dev {
 	struct list_head		unbound_next;
 };
 
+#define VFIO_MEDIATED	(1 << 0)
+#define VFIO_NOIOMMU	(1 << 1)
+
 struct vfio_group {
 	struct kref			kref;
 	int				minor;
@@ -83,7 +86,7 @@  struct vfio_group {
 	struct mutex			unbound_lock;
 	atomic_t			opened;
 	wait_queue_head_t		container_q;
-	bool				noiommu;
+	unsigned int			flags;
 	unsigned int			dev_counter;
 	struct kvm			*kvm;
 	struct blocking_notifier_head	notifier;
@@ -336,7 +339,7 @@  static void vfio_group_unlock_and_free(struct vfio_group *group)
  * Group objects - create, release, get, put, search
  */
 static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
-		bool noiommu)
+		unsigned int flags)
 {
 	struct vfio_group *group, *tmp;
 	struct device *dev;
@@ -355,7 +358,7 @@  static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
 	atomic_set(&group->opened, 0);
 	init_waitqueue_head(&group->container_q);
 	group->iommu_group = iommu_group;
-	group->noiommu = noiommu;
+	group->flags = flags;
 	BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
 
 	group->nb.notifier_call = vfio_iommu_group_notifier;
@@ -391,8 +394,8 @@  static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
 	}
 
 	dev = device_create(vfio.class, NULL,
-			    MKDEV(MAJOR(vfio.group_devt), minor),
-			    group, "%s%d", group->noiommu ? "noiommu-" : "",
+			    MKDEV(MAJOR(vfio.group_devt), minor), group, "%s%d",
+			    (group->flags & VFIO_NOIOMMU) ? "noiommu-" : "",
 			    iommu_group_id(iommu_group));
 	if (IS_ERR(dev)) {
 		vfio_free_group_minor(minor);
@@ -778,8 +781,8 @@  void vfio_uninit_group_dev(struct vfio_device *device)
 }
 EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
 
-#ifdef CONFIG_VFIO_NOIOMMU
-static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev)
+static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
+		unsigned int flags)
 {
 	struct iommu_group *iommu_group;
 	struct vfio_group *group;
@@ -794,7 +797,7 @@  static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev)
 	if (ret)
 		goto out_put_group;
 
-	group = vfio_create_group(iommu_group, true);
+	group = vfio_create_group(iommu_group, flags);
 	if (IS_ERR(group)) {
 		ret = PTR_ERR(group);
 		goto out_remove_device;
@@ -808,7 +811,6 @@  static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev)
 	iommu_group_put(iommu_group);
 	return ERR_PTR(ret);
 }
-#endif
 
 static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
 {
@@ -827,7 +829,7 @@  static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
 		if (noiommu && !iommu_present(dev->bus)) {
 			add_taint(TAINT_USER, LOCKDEP_STILL_OK);
 			dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
-			return vfio_noiommu_group_alloc(dev);
+			return vfio_noiommu_group_alloc(dev, VFIO_NOIOMMU);
 		}
 #endif
 		return ERR_PTR(-EINVAL);
@@ -839,7 +841,7 @@  static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
 	 */
 	group = vfio_group_get_from_iommu(iommu_group);
 	if (!group) {
-		group = vfio_create_group(iommu_group, false);
+		group = vfio_create_group(iommu_group, 0);
 		if (!IS_ERR(group))
 			return group;
 	}
@@ -848,10 +850,13 @@  static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
 	return group;
 }
 
-int vfio_register_group_dev(struct vfio_device *device)
+static int __vfio_register_dev(struct vfio_device *device,
+		struct vfio_group *group)
 {
 	struct vfio_device *existing_device;
-	struct vfio_group *group;
+
+	if (IS_ERR(group))
+		return PTR_ERR(group);
 
 	/*
 	 * If the driver doesn't specify a set then the device is added to a
@@ -860,16 +865,12 @@  int vfio_register_group_dev(struct vfio_device *device)
 	if (!device->dev_set)
 		vfio_assign_device_set(device, device);
 
-	group = vfio_group_find_or_alloc(device->dev);
-	if (IS_ERR(group))
-		return PTR_ERR(group);
-
 	existing_device = vfio_group_get_device(group, device->dev);
 	if (existing_device) {
 		dev_WARN(device->dev, "Device already exists on group %d\n",
 			 iommu_group_id(group->iommu_group));
 		vfio_device_put(existing_device);
-		if (group->noiommu)
+		if (group->flags & (VFIO_NOIOMMU | VFIO_MEDIATED))
 			iommu_group_remove_device(device->dev);
 		iommu_group_put(group->iommu_group);
 		return -EBUSY;
@@ -888,8 +889,21 @@  int vfio_register_group_dev(struct vfio_device *device)
 
 	return 0;
 }
+
+int vfio_register_group_dev(struct vfio_device *device)
+{
+	return __vfio_register_dev(device,
+		vfio_group_find_or_alloc(device->dev));
+}
 EXPORT_SYMBOL_GPL(vfio_register_group_dev);
 
+int vfio_register_mediated_dev(struct vfio_device *device)
+{
+	return __vfio_register_dev(device,
+		vfio_noiommu_group_alloc(device->dev, VFIO_MEDIATED));
+}
+EXPORT_SYMBOL_GPL(vfio_register_mediated_dev);
+
 /**
  * Get a reference to the vfio_device for a device.  Even if the
  * caller thinks they own the device, they could be racing with a
@@ -1016,7 +1030,7 @@  void vfio_unregister_group_dev(struct vfio_device *device)
 	if (list_empty(&group->device_list))
 		wait_event(group->container_q, !group->container);
 
-	if (group->noiommu)
+	if (group->flags & (VFIO_NOIOMMU | VFIO_MEDIATED))
 		iommu_group_remove_device(device->dev);
 	iommu_group_put(group->iommu_group);
 }
@@ -1363,7 +1377,7 @@  static int vfio_group_set_container(struct vfio_group *group, int container_fd)
 	if (atomic_read(&group->container_users))
 		return -EINVAL;
 
-	if (group->noiommu && !capable(CAP_SYS_RAWIO))
+	if ((group->flags & VFIO_NOIOMMU) && !capable(CAP_SYS_RAWIO))
 		return -EPERM;
 
 	f = fdget(container_fd);
@@ -1383,7 +1397,7 @@  static int vfio_group_set_container(struct vfio_group *group, int container_fd)
 
 	/* Real groups and fake groups cannot mix */
 	if (!list_empty(&container->group_list) &&
-	    container->noiommu != group->noiommu) {
+	    container->noiommu != (group->flags & VFIO_NOIOMMU)) {
 		ret = -EPERM;
 		goto unlock_out;
 	}
@@ -1397,7 +1411,7 @@  static int vfio_group_set_container(struct vfio_group *group, int container_fd)
 	}
 
 	group->container = container;
-	container->noiommu = group->noiommu;
+	container->noiommu = (group->flags & VFIO_NOIOMMU);
 	list_add(&group->container_next, &container->group_list);
 
 	/* Get a reference on the container and mark a user within the group */
@@ -1421,7 +1435,7 @@  static int vfio_group_add_container_user(struct vfio_group *group)
 	if (!atomic_inc_not_zero(&group->container_users))
 		return -EINVAL;
 
-	if (group->noiommu) {
+	if (group->flags & VFIO_NOIOMMU) {
 		atomic_dec(&group->container_users);
 		return -EPERM;
 	}
@@ -1446,7 +1460,7 @@  static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
 	    !group->container->iommu_driver || !vfio_group_viable(group))
 		return -EINVAL;
 
-	if (group->noiommu && !capable(CAP_SYS_RAWIO))
+	if ((group->flags & VFIO_NOIOMMU) && !capable(CAP_SYS_RAWIO))
 		return -EPERM;
 
 	device = vfio_device_get_from_name(group, buf);
@@ -1493,7 +1507,7 @@  static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
 
 	fd_install(fdno, filep);
 
-	if (group->noiommu)
+	if (group->flags & VFIO_NOIOMMU)
 		dev_warn(device->dev, "vfio-noiommu device opened by user "
 			 "(%s:%d)\n", current->comm, task_pid_nr(current));
 	return fdno;
@@ -1589,7 +1603,7 @@  static int vfio_group_fops_open(struct inode *inode, struct file *filep)
 	if (!group)
 		return -ENODEV;
 
-	if (group->noiommu && !capable(CAP_SYS_RAWIO)) {
+	if ((group->flags & VFIO_NOIOMMU) && !capable(CAP_SYS_RAWIO)) {
 		vfio_group_put(group);
 		return -EPERM;
 	}
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index f7083c2fd0d099..2ffbb2d02c9346 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -75,6 +75,7 @@  void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
 			 const struct vfio_device_ops *ops);
 void vfio_uninit_group_dev(struct vfio_device *device);
 int vfio_register_group_dev(struct vfio_device *device);
+int vfio_register_mediated_dev(struct vfio_device *device);
 void vfio_unregister_group_dev(struct vfio_device *device);
 extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);
 extern void vfio_device_put(struct vfio_device *device);
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index c313ab4d1f4e4e..f59218e03dd1b4 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -553,7 +553,7 @@  static int mbochs_probe(struct mdev_device *mdev)
 	mbochs_create_config_space(mdev_state);
 	mbochs_reset(mdev_state);
 
-	ret = vfio_register_group_dev(&mdev_state->vdev);
+	ret = vfio_register_mediated_dev(&mdev_state->vdev);
 	if (ret)
 		goto err_mem;
 	dev_set_drvdata(&mdev->dev, mdev_state);
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index 8d1a80a0722aa9..4df380014ad914 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -258,7 +258,7 @@  static int mdpy_probe(struct mdev_device *mdev)
 
 	mdpy_count++;
 
-	ret = vfio_register_group_dev(&mdev_state->vdev);
+	ret = vfio_register_mediated_dev(&mdev_state->vdev);
 	if (ret)
 		goto err_mem;
 	dev_set_drvdata(&mdev->dev, mdev_state);
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 5983cdb16e3d1d..ef9f48bfe8d04f 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -741,7 +741,7 @@  static int mtty_probe(struct mdev_device *mdev)
 
 	mtty_create_config_space(mdev_state);
 
-	ret = vfio_register_group_dev(&mdev_state->vdev);
+	ret = vfio_register_mediated_dev(&mdev_state->vdev);
 	if (ret)
 		goto err_vconfig;
 	dev_set_drvdata(&mdev->dev, mdev_state);