On Tue, 21 Feb 2023 18:22:31 -0800 Yi Liu <yi.l.liu@xxxxxxxxx> wrote: > 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. I updated the title and commit log so as not to further construe that documentation can impose a requirement, otherwise applied to vfio next branch for v6.4. Thanks, Alex
