Merge tag 'vfio-v6.1-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Prune private items from vfio_pci_core.h to a new internal header,
   fix missed function rename, and refactor vfio-pci interrupt defines
   (Jason Gunthorpe)

 - Create consistent naming and handling of ioctls with a function per
   ioctl for vfio-pci and vfio group handling, use proper type args
   where available (Jason Gunthorpe)

 - Implement a set of low power device feature ioctls allowing userspace
   to make use of power states such as D3cold where supported (Abhishek
   Sahu)

 - Remove device counter on vfio groups, which had restricted the page
   pinning interface to singleton groups to account for limitations in
   the type1 IOMMU backend. Document usage as limited to emulated IOMMU
   devices, ie. traditional mdev devices where this restriction is
   consistent (Jason Gunthorpe)

 - Correct function prefix in hisi_acc driver incurred during previous
   refactoring (Shameer Kolothum)

 - Correct typo and remove redundant warning triggers in vfio-fsl driver
   (Christophe JAILLET)

 - Introduce device level DMA dirty tracking uAPI and implementation in
   the mlx5 variant driver (Yishai Hadas & Joao Martins)

 - Move much of the vfio_device life cycle management into vfio core,
   simplifying and avoiding duplication across drivers. This also
   facilitates adding a struct device to vfio_device which begins the
   introduction of device rather than group level user support and fills
   a gap allowing userspace identify devices as vfio capable without
   implicit knowledge of the driver (Kevin Tian & Yi Liu)

 - Split vfio container handling to a separate file, creating a more
   well defined API between the core and container code, masking IOMMU
   backend implementation from the core, allowing for an easier future
   transition to an iommufd based implementation of the same (Jason
   Gunthorpe)

 - Attempt to resolve race accessing the iommu_group for a device
   between vfio releasing DMA ownership and removal of the device from
   the IOMMU driver. Follow-up with support to allow vfio_group to exist
   with NULL iommu_group pointer to support existing userspace use cases
   of holding the group file open (Jason Gunthorpe)

 - Fix error code and hi/lo register manipulation issues in the hisi_acc
   variant driver, along with various code cleanups (Longfang Liu)

 - Fix a prior regression in GVT-g group teardown, resulting in
   unreleased resources (Jason Gunthorpe)

 - A significant cleanup and simplification of the mdev interface,
   consolidating much of the open coded per driver sysfs interface
   support into the mdev core (Christoph Hellwig)

 - Simplification of tracking and locking around vfio_groups that fall
   out from previous refactoring (Jason Gunthorpe)

 - Replace trivial open coded f_ops tests with new helper (Alex
   Williamson)

* tag 'vfio-v6.1-rc1' of https://github.com/awilliam/linux-vfio: (77 commits)
  vfio: More vfio_file_is_group() use cases
  vfio: Make the group FD disassociate from the iommu_group
  vfio: Hold a reference to the iommu_group in kvm for SPAPR
  vfio: Add vfio_file_is_group()
  vfio: Change vfio_group->group_rwsem to a mutex
  vfio: Remove the vfio_group->users and users_comp
  vfio/mdev: add mdev available instance checking to the core
  vfio/mdev: consolidate all the description sysfs into the core code
  vfio/mdev: consolidate all the available_instance sysfs into the core code
  vfio/mdev: consolidate all the name sysfs into the core code
  vfio/mdev: consolidate all the device_api sysfs into the core code
  vfio/mdev: remove mtype_get_parent_dev
  vfio/mdev: remove mdev_parent_dev
  vfio/mdev: unexport mdev_bus_type
  vfio/mdev: remove mdev_from_dev
  vfio/mdev: simplify mdev_type handling
  vfio/mdev: embedd struct mdev_parent in the parent data structure
  vfio/mdev: make mdev.h standalone includable
  drm/i915/gvt: simplify vgpu configuration management
  drm/i915/gvt: fix a memory leak in intel_gvt_init_vgpu_types
  ...

1 files changed, 32 insertions, 13 deletions

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index ce1b01d02c51..495ceabffe88 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -24,6 +24,9 @@
 struct kvm_vfio_group {
 	struct list_head node;
 	struct file *file;
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+	struct iommu_group *iommu_group;
+#endif
 };
 
 struct kvm_vfio {
@@ -61,6 +64,23 @@ static bool kvm_vfio_file_enforced_coherent(struct file *file)
 	return ret;
 }
 
+static bool kvm_vfio_file_is_group(struct file *file)
+{
+	bool (*fn)(struct file *file);
+	bool ret;
+
+	fn = symbol_get(vfio_file_is_group);
+	if (!fn)
+		return false;
+
+	ret = fn(file);
+
+	symbol_put(vfio_file_is_group);
+
+	return ret;
+}
+
+#ifdef CONFIG_SPAPR_TCE_IOMMU
 static struct iommu_group *kvm_vfio_file_iommu_group(struct file *file)
 {
 	struct iommu_group *(*fn)(struct file *file);
@@ -77,16 +97,15 @@ static struct iommu_group *kvm_vfio_file_iommu_group(struct file *file)
 	return ret;
 }
 
-#ifdef CONFIG_SPAPR_TCE_IOMMU
 static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm,
 					     struct kvm_vfio_group *kvg)
 {
-	struct iommu_group *grp = kvm_vfio_file_iommu_group(kvg->file);
-
-	if (WARN_ON_ONCE(!grp))
+	if (WARN_ON_ONCE(!kvg->iommu_group))
 		return;
 
-	kvm_spapr_tce_release_iommu_group(kvm, grp);
+	kvm_spapr_tce_release_iommu_group(kvm, kvg->iommu_group);
+	iommu_group_put(kvg->iommu_group);
+	kvg->iommu_group = NULL;
 }
 #endif
 
@@ -136,7 +155,7 @@ static int kvm_vfio_group_add(struct kvm_device *dev, unsigned int fd)
 		return -EBADF;
 
 	/* Ensure the FD is a vfio group FD.*/
-	if (!kvm_vfio_file_iommu_group(filp)) {
+	if (!kvm_vfio_file_is_group(filp)) {
 		ret = -EINVAL;
 		goto err_fput;
 	}
@@ -236,19 +255,19 @@ static int kvm_vfio_group_set_spapr_tce(struct kvm_device *dev,
 	mutex_lock(&kv->lock);
 
 	list_for_each_entry(kvg, &kv->group_list, node) {
-		struct iommu_group *grp;
-
 		if (kvg->file != f.file)
 			continue;
 
-		grp = kvm_vfio_file_iommu_group(kvg->file);
-		if (WARN_ON_ONCE(!grp)) {
-			ret = -EIO;
-			goto err_fdput;
+		if (!kvg->iommu_group) {
+			kvg->iommu_group = kvm_vfio_file_iommu_group(kvg->file);
+			if (WARN_ON_ONCE(!kvg->iommu_group)) {
+				ret = -EIO;
+				goto err_fdput;
+			}
 		}
 
 		ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
-						       grp);
+						       kvg->iommu_group);
 		break;
 	}