vfio: support notifier chain in vfio_group

Beyond vfio_iommu events, users might also be interested in
vfio_group events. For example, if a vfio_group is used along
with Qemu/KVM, whenever kvm pointer is set to/cleared from the
vfio_group, users could be notified.

Currently only VFIO_GROUP_NOTIFY_SET_KVM supported.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Jike Song <jike.song@intel.com>
[aw: remove use of new typedef]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 0e5201f207d3..edf9b2cad277 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -111,11 +111,15 @@ extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
 /* each type has independent events */
 enum vfio_notify_type {
         VFIO_IOMMU_NOTIFY = 0,
+        VFIO_GROUP_NOTIFY = 1,
 };
 
 /* events for VFIO_IOMMU_NOTIFY */
 #define VFIO_IOMMU_NOTIFY_DMA_UNMAP     BIT(0)
 
+/* events for VFIO_GROUP_NOTIFY */
+#define VFIO_GROUP_NOTIFY_SET_KVM       BIT(0)
+
 extern int vfio_register_notifier(struct device *dev,
                                   enum vfio_notify_type type,
                                   unsigned long *required_events,
@@ -124,6 +128,9 @@ extern int vfio_unregister_notifier(struct device *dev,
                                     enum vfio_notify_type type,
                                     struct notifier_block *nb);
 
+struct kvm;
+extern void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
+
 /*
  * Sub-module helpers
  */