> From: Lu Baolu [mailto:baolu.lu@xxxxxxxxxxxxxxx] > Sent: Thursday, August 30, 2018 12:09 PM > [...] > > In order to distinguish the IOMMU-capable mediated devices from those > which still need to rely on parent devices, this patch set adds a > domain type attribute to each mdev. > > enum mdev_domain_type { > DOMAIN_TYPE_NO_IOMMU, /* Don't need any IOMMU support. > * All isolation and protection > * are handled by the parent > * device driver with a device > * specific mechanism. > */ > DOMAIN_TYPE_ATTACH_PARENT, /* IOMMU can isolate and > protect > * the mdev, and the isolation > * domain should be attaced with > * the parent device. > */ > }; > ATTACH_PARENT is not like a good counterpart to NO_IOMMU. what about DOMAIN_TYPE_NO_IOMMU/DOMAIN_TYPE_IOMMU? whether to attach parent device is just internal logic. Alternatively DOMAIN_TYPE_SOFTWARE/DOMAIN_TYPE_HARDWARE, where software means iommu_domain is managed by software while the other means managed by hardware. One side note to Alex - with multiple domain extension in IOMMU layer, this version combines IOMMU-capable usages in VFIO: PASID-based (as in scalable iov) and RID-based (as the usage of mdev wrapper on any device). Both cases share the common path - just binding the domain to the parent device of mdev. IOMMU layer will handle two cases differently later. Thanks Kevin
