Re: [PATCH RESEND 08/10] iommu/amd: Add support for add/remove device for IOPF

[Jason Gunthorpe <jgg@ziepe.ca>]

On Wed, Aug 23, 2023 at 02:04:13PM +0000, Vasant Hegde wrote:

> diff --git a/drivers/iommu/amd/ppr.c b/drivers/iommu/amd/ppr.c
> index 8cbcdb9c1669..2e5ca4847eda 100644
> --- a/drivers/iommu/amd/ppr.c
> +++ b/drivers/iommu/amd/ppr.c
> @@ -168,3 +168,53 @@ int amd_iommu_page_response(struct device *dev,
>  	return amd_iommu_complete_ppr(pdev, resp->pasid, resp->code,
>  				      resp->grpid);
>  }
> +
> +int amd_iommu_iopf_add_device(struct amd_iommu *iommu, struct device *dev)
> +{
> +	unsigned long flags;
> +	int ret = -EINVAL;
> +
> +	raw_spin_lock_irqsave(&iommu->lock, flags);
> +
> +	if (!iommu->iopf_queue)
> +		goto out;
> +
> +	ret = iopf_queue_add_device(iommu->iopf_queue, dev);
> +	if (ret)
> +		goto out;
> +
> +	ret = iommu_register_device_fault_handler(dev, iommu_queue_iopf, dev);
> +	if (ret)
> +		iopf_queue_remove_device(iommu->iopf_queue, dev);
> +
> +out:
> +	raw_spin_unlock_irqrestore(&iommu->lock, flags);
> +	return ret;
> +}

Please assume the iopf rework will arrive before your series:

https://lore.kernel.org/linux-iommu/20230817234047.195194-1-baolu.lu@linux.intel.com/

In the new arrangement the work queue to is used by the SVA code to
move the blocking handle_mm_fault out of the global page request
processing.

I would expect there to be one (unbound) work_queue for SVA, shared by
all SVA domains.

Jason