as some vfio_device drivers require a kvm pointer to be set in their open_device and kvm pointer is set to VFIO in GROUP_ADD path. Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx> --- v2: - Adopt Alex's suggestion v1: https://lore.kernel.org/kvm/20230221034114.135386-1-yi.l.liu@xxxxxxxxx/ --- Documentation/virt/kvm/devices/vfio.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/virt/kvm/devices/vfio.rst b/Documentation/virt/kvm/devices/vfio.rst index 2d20dc561069..79b6811bb4f3 100644 --- a/Documentation/virt/kvm/devices/vfio.rst +++ b/Documentation/virt/kvm/devices/vfio.rst @@ -39,3 +39,10 @@ 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 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. -- 2.34.1
