as some vfio_device's open_device op requires kvm pointer and kvm pointer set is part of GROUP_ADD. Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx> --- Documentation/virt/kvm/devices/vfio.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/virt/kvm/devices/vfio.rst b/Documentation/virt/kvm/devices/vfio.rst index 2d20dc561069..5722e283f1b5 100644 --- a/Documentation/virt/kvm/devices/vfio.rst +++ b/Documentation/virt/kvm/devices/vfio.rst @@ -39,3 +39,8 @@ KVM_DEV_VFIO_GROUP attributes: - @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 before vfio_device's +open_device op which is called in the ioctl VFIO_GROUP_GET_DEVICE_FD. -- 2.34.1
