as some vfio_device's open_device op requires kvm pointer and kvm pointer
set is part of GROUP_ADD.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230421053611.55839-1-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- @groupfd is a file descriptor for a VFIO group;
- @tablefd is a file descriptor for a TCE table allocated via
KVM_CREATE_SPAPR_TCE.
+
+The GROUP_ADD operation above should be invoked prior to accessing the
+device file descriptor via VFIO_GROUP_GET_DEVICE_FD in order to support
+drivers which require a kvm pointer to be set in their .open_device()
+callback.