Re: [PATCH v6 2/6] iommufd: Add IOMMU_HWPT_INVALIDATE

Nicolin Chen
2023-12-05T17:33:54Z

On Mon, Dec 04, 2023 at 10:48:50AM -0400, Jason Gunthorpe wrote:

> > Or am I missing some point here?
>
> It sounds Ok, we just have to understand what userspace should be
> doing and how much of this the kernel should implement.
>
> It seems to me that the error code should return the gerror and the
> req_num should indicate the halted cons. The vmm should relay both
> into the virtual registers.

I see your concern. I will take a closer look and see if we can
add to the initial version of arm_smmu_cache_invalidate_user().
Otherwise, we can add later.

Btw, VT-d seems to want the error_code and reports in the VT-d
specific invalidate entry structure, as Kevin and Yi had that
discussion in the other side of the thread.

Thanks
Nicolin