> > I am working on an IOMMU driver feature that allows a user to specify > > if the DMA from a device should be translated by IOMMU or not. > > Presently, we support only all devices or none mode i.e. if user > > specifies "iommu=pt" [X86] or "iommu.passthrough" [ARM64] through > > kernel command line, all the devices would be in pass through mode and > > we don't have per device granularity, but, we were requested by a > > customer to selectively put devices in pass through mode and not all. > > Most iommu vendor drivers have switched from per-device to per-group domain > (a.k.a. default domain). So per-group pass-through mode makes more sense? > > By the way, can we extend this to "per-group default domain type", instead of > only "per-group pass-through mode"? Currently we have system level default > domain type, if we have finer granularity of default domain type, both iommu > drivers and end users will benefit from it.
Sure! Makes sense.. per-group default domain type sounds good. > > I am looking for a consensus on **how the kernel command line argument > > should look like and path for sysfs entry**. Also, please note that if > > a device is put in pass through mode it won't be available for the > > guest and that's ok. > > Just out of curiosity, what's the limitation for a device using pass- through > DMA > domain to be assignable. Sorry! I don't know about assignable devices. Probably, Ashok or Jacob could answer this question Regards, Sai _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
