On 24/11/17 08:23, Bob Liu wrote: > On 2017/10/6 21:31, Jean-Philippe Brucker wrote: >> Add two new ioctl for VFIO containers. VFIO_DEVICE_BIND_PROCESS creates a >> bond between a container and a process address space, identified by a >> device-specific ID named PASID. This allows the device to target DMA >> transactions at the process virtual addresses without a need for mapping >> and unmapping buffers explicitly in the IOMMU. The process page tables are >> shared with the IOMMU, and mechanisms such as PCI ATS/PRI may be used to >> handle faults. VFIO_DEVICE_UNBIND_PROCESS removed a bond identified by a >> PASID. >> > > How about hide bind/unbind into ioctl(VFIO_SET_IOMMU)? > e.g always bind to current process in SET_IOMMU. > > Not sure about the real use case. I guess you could introduce a new VFIO IOMMU type for this. I think this would be useful for SVA without PASID: if the device supports I/O page faults, use SET_IOMMU with a VFIO_SVA_IOMMU type (for example) and the process is bound automatically to the default translation context of the device. This requires a new IOMMU type because the MAP/UNMAP ioctl won't work anymore. I'm not keen on introducing loads of new features in the APIs at the moment, because I only have the IOMMU point of view, not many endpoint users. Thanks, Jean
