On Thu, Oct 31, 2024 at 02:28:12PM +0800, Zhangfei Gao wrote:
On Thu, 31 Oct 2024 at 05:36, Nicolin Chen nicolinc@nvidia.com wrote:
Following the previous vIOMMU series, this adds another vDEVICE structure, representing the association from an iommufd_device to an iommufd_viommu. This gives the whole architecture a new "v" layer: _______________________________________________________________________ | iommufd (with vIOMMU/vDEVICE) | | _____________ _____________ | | | | | | | | |----------------| vIOMMU |<---| vDEVICE |<------| | | | | | |_____________| | | | | ______ | | _____________ ___|____ | | | | | | | | | | | | | | | IOAS |<---|(HWPT_PAGING)|<---| HWPT_NESTED |<--| DEVICE | | | | |______| |_____________| |_____________| |________| | |______|________|______________|__________________|_______________|_____| | | | | | ______v_____ | ______v_____ ______v_____ ___v__ | struct | | PFN | (paging) | | (nested) | |struct| |iommu_device| |------>|iommu_domain|<----|iommu_domain|<----|device| |____________| storage|____________| |____________| |______|
This vDEVICE object is used to collect and store all vIOMMU-related device information/attributes in a VM. As an initial series for vDEVICE, add only the virt_id to the vDEVICE, which is a vIOMMU specific device ID in a VM: e.g. vSID of ARM SMMUv3, vDeviceID of AMD IOMMU, and vRID of Intel VT-d to a Context Table. This virt_id helps IOMMU drivers to link the vID to a pID of the device against the physical IOMMU instance. This is essential for a vIOMMU-based invalidation, where the request contains a device's vID for a device cache flush, e.g. ATC invalidation.
Therefore, with this vDEVICE object, support a vIOMMU-based invalidation, by reusing IOMMUFD_CMD_HWPT_INVALIDATE for a vIOMMU object to flush cache with a given driver data.
As for the implementation of the series, add driver support in ARM SMMUv3 for a real world use case.
This series is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_viommu_p2-v6 (QEMU branch for testing will be provided in Jason's nesting series)
Thanks Nico
I tested on aarch64, functions are OK.
But with some hacks https://github.com/Linaro/linux-kernel-uadk/commit/22f47d6f3a34a0867a187473b...
Though we will have some small changes to this two series (and possibly a small change to SMMUv3 driver too for that flags in the hacks), would you mind giving this two series a Tested-by?
Thanks! Nicolin