On Fri, Oct 25, 2024 at 04:49:42PM -0700, Nicolin Chen wrote:
> Add a new IOMMUFD_OBJ_VIOMMU with an iommufd_viommu structure to represent
> a slice of physical IOMMU device passed to or shared with a user space VM.
> This slice, now a vIOMMU object, is a group of virtualization resources of
> a physical IOMMU's, such as:
> - Security namespace for guest owned ID, e.g. guest-controlled cache tags
> - Access to a sharable nesting parent pagetable across physical IOMMUs
> - Virtualization of various platforms IDs, e.g. RIDs and others
> - Delivery of paravirtualized invalidation
> - Direct assigned invalidation queues
> - Direct assigned interrupts
> - Non-affiliated event reporting
>
> Add a new viommu_alloc op in iommu_ops, for drivers to allocate their own
> vIOMMU structures. And this allocation also needs a free(), so add struct
> iommufd_viommu_ops.
>
> To simplify a vIOMMU allocation, provide a iommufd_viommu_alloc() helper.
> It's suggested that a driver should embed a core-level viommu structure in
> its driver-level viommu struct and call the iommufd_viommu_alloc() helper,
> meanwhile the driver can also implement a viommu ops:
> struct my_driver_viommu {
> struct iommufd_viommu core;
> /* driver-owned properties/features */
> ....
> };
>
> static const struct iommufd_viommu_ops my_driver_viommu_ops = {
> .free = my_driver_viommu_free,
> /* future ops for virtualization features */
> ....
> };
>
> static struct iommufd_viommu my_driver_viommu_alloc(...)
> {
> struct my_driver_viommu *my_viommu =
> iommufd_viommu_alloc(ictx, my_driver_viommu, core,
> my_driver_viommu_ops);
> /* Init my_viommu and related HW feature */
> ....
> return &my_viommu->core;
> }
>
> static struct iommu_domain_ops my_driver_domain_ops = {
> ....
> .viommu_alloc = my_driver_viommu_alloc,
> };
>
> To make the Kernel config work between a driver and the iommufd core, move
> the _iommufd_object_alloc helper into a new driver.c file that builds with
> CONFIG_IOMMUFD_DRIVER.
>
> Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> ---
> drivers/iommu/iommufd/Makefile | 2 +-
> drivers/iommu/iommufd/iommufd_private.h | 4 --
> include/linux/iommu.h | 14 +++++++
> include/linux/iommufd.h | 53 +++++++++++++++++++++++++
> drivers/iommu/iommufd/driver.c | 38 ++++++++++++++++++
> drivers/iommu/iommufd/main.c | 32 ---------------
> 6 files changed, 106 insertions(+), 37 deletions(-)
> create mode 100644 drivers/iommu/iommufd/driver.c
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Jason
