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Date: Tue, 7 May 2024 21:18:40 -0300
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>, Joerg Roedel <joro@8bytes.org>,
	Will Deacon <will@kernel.org>, Robin Murphy <robin.murphy@arm.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Nicolin Chen <nicolinc@nvidia.com>, Yi Liu <yi.l.liu@intel.com>,
	Jacob Pan <jacob.jun.pan@linux.intel.com>,
	Joel Granados <j.granados@samsung.com>, iommu@lists.linux.dev,
	virtualization@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 6/9] iommufd: Fault-capable hwpt attach/detach/replace
Message-ID: <20240508001840.GO4718@ziepe.ca>
References: <20240430145710.68112-1-baolu.lu@linux.intel.com>
 <20240430145710.68112-7-baolu.lu@linux.intel.com>
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In-Reply-To: <20240430145710.68112-7-baolu.lu@linux.intel.com>

On Tue, Apr 30, 2024 at 10:57:07PM +0800, Lu Baolu wrote:
> diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c
> index 13125c0feecb..6357229bf3b4 100644
> --- a/drivers/iommu/iommufd/fault.c
> +++ b/drivers/iommu/iommufd/fault.c
> @@ -15,6 +15,124 @@
>  #include "../iommu-priv.h"
>  #include "iommufd_private.h"
>  
> +static int iommufd_fault_iopf_enable(struct iommufd_device *idev)
> +{
> +	int ret;
> +
> +	if (idev->iopf_enabled)
> +		return 0;
> +
> +	ret = iommu_dev_enable_feature(idev->dev, IOMMU_DEV_FEAT_IOPF);
> +	if (ret)
> +		return ret;
> +
> +	idev->iopf_enabled = true;
> +
> +	return 0;
> +}

I would greatly prefer we remove this from the drivers :\ I guess it
is Ok for now

Doesn't this need a counter? We can have many fault capable PASIDs?
That will get changed in the PASID series?

Jason