Re: [Intel-gfx] [PATCH v7 8/9] vfio/pci: Extend VFIO_DEVICE_GET_PCI_HOT_RESET_INFO for vfio device cdev

Liu, Yi L
2023-06-13T12:50:52Z

> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Tuesday, June 13, 2023 7:47 PM
>
> On Fri, Jun 02, 2023 at 05:15:14AM -0700, Yi Liu wrote:
> > +/*
> > + * Return devid for a device which is affected by hot-reset.
> > + * - valid devid > 0 for the device that is bound to the input
> > + * iommufd_ctx.
> > + * - devid == VFIO_PCI_DEVID_OWNED for the device that has not
> > + * been bound to any iommufd_ctx but other device within its
> > + * group has been bound to the input iommufd_ctx.
> > + * - devid == VFIO_PCI_DEVID_NOT_OWNED for others. e.g. device
> > + * is bound to other iommufd_ctx etc.
> > + */
> > +int vfio_iommufd_device_hot_reset_devid(struct vfio_device *vdev,
> > + struct iommufd_ctx *ictx)
> > +{
> > + struct iommu_group *group;
> > + int devid;
> > +
> > + if (vfio_iommufd_device_ictx(vdev) == ictx)
> > + return vfio_iommufd_device_id(vdev);
> > +
> > + group = iommu_group_get(vdev->dev);
> > + if (!group)
> > + return VFIO_PCI_DEVID_NOT_OWNED;
> > +
> > + if (iommufd_ctx_has_group(ictx, group))
> > + devid = VFIO_PCI_DEVID_OWNED;
> > + else
> > + devid = VFIO_PCI_DEVID_NOT_OWNED;
> > +
> > + iommu_group_put(group);
> > +
> > + return devid;
> > +}
> > +EXPORT_SYMBOL_GPL(vfio_iommufd_device_hot_reset_devid);
>
> This function really should not be in the core iommufd.c file - it is
> a purely vfio-pci function - why did you have to place it here?

Put it here can avoid calling iommufd_ctx_has_group() in vfio-pci,
which requires to import IOMMUFD_NS. If this reason is not so
strong I can move it back to vfio-pci code.

Regards,
Yi Liu