Re: [PATCH v2 2/4] iommufd: Move iommufd_sw_msi and related functions to driver.c

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Feb 27, 2025 at 05:31:16PM -0800, Nicolin Chen wrote:
> @@ -187,6 +188,8 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
>  					     enum iommufd_object_type type);
>  struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
>  				       unsigned long vdev_id);
> +int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
> +		   phys_addr_t msi_addr);

This should probably go into drivers/iommu/iommu-priv.h ?

> +int iommufd_sw_msi_install(struct iommufd_ctx *ictx,
> +			   struct iommufd_hwpt_paging *hwpt_paging,
> +			   struct iommufd_sw_msi_map *msi_map)
> +{
> +	unsigned long iova;
> +
> +	lockdep_assert_held(&ictx->sw_msi_lock);
> +
> +	iova = msi_map->sw_msi_start + msi_map->pgoff * PAGE_SIZE;
> +	if (!test_bit(msi_map->id, hwpt_paging->present_sw_msi.bitmap)) {
> +		int rc;
> +
> +		rc = iommu_map(hwpt_paging->common.domain, iova,
> +			       msi_map->msi_addr, PAGE_SIZE,
> +			       IOMMU_WRITE | IOMMU_READ | IOMMU_MMIO,
> +			       GFP_KERNEL_ACCOUNT);
> +		if (rc)
> +			return rc;
> +		__set_bit(msi_map->id, hwpt_paging->present_sw_msi.bitmap);
> +	}
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(iommufd_sw_msi_install, "IOMMUFD");

Stubbed out too if CONFIG_IRQ_MSI_IOMMU ?

I'm still wondering if we should use a function pointer, how big was
this compiled anyhow?

Jason