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.
How about something like "iommu.passthrough=0/1"? And please add the
parameter to the kernel documentation too.
Joerg