On Wed, Feb 05, 2020 at 08:56:48AM -0400, Jason Gunthorpe wrote: > On Wed, Feb 05, 2020 at 03:50:14PM +0800, Jason Wang wrote: > > > Would it be better for the map/umnap logic to happen inside each device ? > > > Devices that needs the IOMMU will call iommu APIs from inside the driver callback. > > > > Technically, this can work. But if it can be done by vhost-vpda it will make > > the vDPA driver more compact and easier to be implemented. > > Generally speaking, in the kernel, it is normal to not hoist code of > out drivers into subsystems until 2-3 drivers are duplicating that > code. It helps ensure the right design is used > > Jason That's up to the sybsystem maintainer really, as there's also some intuition involved in guessing a specific API is widely useful. In-kernel APIs are flexible, if we find something isn't needed we just drop it. -- MST
