Re: [PATCH 12/14] iommufd: Add APIs to preserve/unpreserve a vfio cdev

[Samiullah Khawaja]

On Mon, Mar 23, 2026 at 01:59:13PM -0700, Vipin Sharma wrote:
> On Tue, Feb 03, 2026 at 10:09:46PM +0000, Samiullah Khawaja wrote:
> > diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
> > +#ifdef CONFIG_IOMMU_LIVEUPDATE
> > +int iommufd_device_preserve(struct liveupdate_session *s,
> > +			    struct iommufd_device *idev,
> > +			    u64 *tokenp)
> > +{
> > +	struct iommufd_group *igroup = idev->igroup;
> > +	struct iommufd_hwpt_paging *hwpt_paging;
> > +	struct iommufd_hw_pagetable *hwpt;
> > +	struct iommufd_attach *attach;
> > +	int ret;
> > +
> > +	mutex_lock(&igroup->lock);
> > +	attach = xa_load(&igroup->pasid_attach, IOMMU_NO_PASID);
> > +	if (!attach) {
> > +		ret = -ENOENT;
> > +		goto out;
> > +	}
>
> Should VFIO in its can_preserve() add this check?

Good Point. We can move this check over there.
> > +void iommufd_device_unpreserve(struct liveupdate_session *s,
> > +			       struct iommufd_device *idev,
> > +			       u64 token)
>
> Where is token used in this function?

Will remove.
>