On 26/01/17 17:15, Joerg Roedel wrote: > On Thu, Jan 19, 2017 at 06:19:15PM +0000, Will Deacon wrote: >> Rather than modify each IOMMU driver to provide different semantics for >> DMA domains, instead we introduce a command line parameter that can be >> used to change the type of the default domain. Passthrough can then be >> specified using "iommu.default_domain=identity" on the kernel command >> line. > > I like the general idea of this, but the above is a terrible name for a > kernel commandline-parameter. The x86 iommus support iommu=pt which is > pretty much the same as this patch does.
Indeed, I was keen on making "iommu=pt" also do this default domain switch itself so we wouldn't need a new option - it didn't *appear* that that would break the AMD driver (as the only other default domain user supporting identity domains) but I may have overlooked something. Robin. > How about something like "iommu.passthrough=0/1"? And please add the > parameter to the kernel documentation too. > > > Joerg > _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
