On Tue, Jul 13, 2021 at 10:48:38PM +0000, Tian, Kevin wrote: > We can still bind to the parent with cookie, but with > iommu_register_ sw_device() IOMMU fd knows that this binding doesn't > need to establish any security context via IOMMU API. AFAIK there is no reason to involve the parent PCI or other device in SW mode. The iommufd doesn't need to be aware of anything there. Jason