> From: Alexey Kardashevskiy <aik@xxxxxxxxx> > Sent: Friday, July 8, 2022 5:46 PM > > >>> > >>> In general, is "domain" something from hardware or it is a software > >>> concept? Thanks, > >>> > > > > 'domain' is a software concept to represent the hardware I/O page > > table. A blocking domain means all DMAs from a device attached to > > this domain are blocked/rejected (equivalent to an empty I/O page > > table), usually enforced in the .attach_dev() callback. > > > > Yes, a comment for why having a NULL .attach_dev() is OK is welcomed. > > > Making it NULL makes __iommu_attach_device() fail, .attach_dev() needs > to return 0 in this crippled environment. Thanks for explaining the > rest, good food for thoughts. > Yeah, that's a typo. 😊
