On Fri, Oct 13, 2023 at 01:58:59PM -0700, Nicolin Chen wrote:
On Fri, Oct 13, 2023 at 12:19:23PM -0300, Jason Gunthorpe wrote:
On Thu, Sep 21, 2023 at 12:51:31AM -0700, Yi Liu wrote:
IOMMU_HWPT_ALLOC already supports iommu_domain allocation for usersapce. But it can only allocate a hw_pagetable that associates to a given IOAS, i.e. only a kernel-managed hw_pagetable of IOMMU_HWPT_TYPE_DEFAULT type.
IOMMU drivers can now support user-managed hw_pagetables, for two-stage translation use cases, that require user data input from the user space.
Extend the IOMMU_HWPT_ALLOC ioctl to accept non-default hwpt_type with a type specified user data. Also, update the @pt_id to accept hwpt_id too besides an ioas_id. Then, pass them to the downstream alloc_fn().
Co-developed-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com
drivers/iommu/iommufd/hw_pagetable.c | 19 ++++++++++++++++++- include/uapi/linux/iommufd.h | 23 +++++++++++++++++++++-- 2 files changed, 39 insertions(+), 3 deletions(-)
Can we also come with a small vt-d patch that does implement an op for this? Or is it too big?
It would be nice if we could wrap IOMMU_HWPT_ALLOC into one self-contained series and another series for invalidate.
We now only use IOMMU_HWPT_ALLOC for nested domain allocations, which won't be supported until the cache_invalidate_user ops is preset?
/* e.g. the following piece is in iommufd_user_managed_hwpt_alloc */
/* Driver is buggy by missing cache_invalidate_user in domain_ops */if (WARN_ON_ONCE(!hwpt->domain->ops->cache_invalidate_user)) {rc = -EINVAL;goto out_abort;}
Hm. That hunk could migrate to the invalidate series.
I'm just leeary of doing the invalidation too considering how complicated it is
Jason