RE: [PATCH v2 10/10] vfio/pci: Add VFIO_DEVICE_GET_PCI_HOT_RESET_GROUP_INFO

Tian, Kevin
2023-03-28T06:23:11Z

> From: Liu, Yi L <yi.l.liu@intel.com>
> Sent: Tuesday, March 28, 2023 11:32 AM
>
> > From: Alex Williamson <alex.williamson@redhat.com>
> > Sent: Tuesday, March 28, 2023 3:26 AM
> >
> > Additionally, VFIO_DEVICE_GET_PCI_HOT_RESET_INFO has a flags arg that
> > isn't used, why do we need a new ioctl vs defining
> > VFIO_PCI_HOT_RESET_FLAG_IOMMUFD_DEV_ID.
>
> Sure. I can follow this suggestion. BTW. I have a doubt here. This new flag
> is set by user. What if in the future kernel has new extensions and needs
> to report something new to the user and add new flags to tell user? Such
> flag is set by kernel. Then the flags field may have two kinds of flags (some
> set by user while some set by kernel). Will it mess up the flags space?
>

flags in a GET_INFO ioctl is for output.

if user needs to use flags as input to select different type of info then it should
be split into multiple GET_INFO cmds.