Re: [PATCH 08/18] iommu: Introduce cache_invalidate API

Andriy Shevchenko
2019-04-09T10:07:25Z

On Mon, Apr 08, 2019 at 04:59:23PM -0700, Jacob Pan wrote:
> From: "Liu, Yi L" <yi.l.liu@linux.intel.com>
>
> In any virtualization use case, when the first translation stage
> is "owned" by the guest OS, the host IOMMU driver has no knowledge
> of caching structure updates unless the guest invalidation activities
> are trapped by the virtualizer and passed down to the host.
>
> Since the invalidation data are obtained from user space and will be
> written into physical IOMMU, we must allow security check at various
> layers. Therefore, generic invalidation data format are proposed here,
> model specific IOMMU drivers need to convert them into their own format.

> +int iommu_cache_invalidate(struct iommu_domain *domain, struct device *dev,
> + struct iommu_cache_invalidate_info *inv_info)
> +{
> + int ret = 0;

Redundant assignment.

> +
> + if (unlikely(!domain->ops->cache_invalidate))
> + return -ENODEV;
> +
> + ret = domain->ops->cache_invalidate(domain, dev, inv_info);
> +
> + return ret;
> +}

--
With Best Regards,
Andy Shevchenko