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Date:   Mon, 17 Jul 2023 16:47:45 +0800
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Subject: Re: [RFC PATCH 5/6] iommu: Support mm PASID 1:1 with sva domain
Content-Language: en-CA
To:     Tina Zhang <tina.zhang@intel.com>, Jason Gunthorpe <jgg@ziepe.ca>,
        "Kevin Tian" <kevin.tian@intel.com>,
        Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Michael Shavit <mshavit@google.com>
CC:     <iommu@lists.linux.dev>, <linux-kernel@vger.kernel.org>
References: <20230707013441.365583-1-tina.zhang@intel.com>
 <20230707013441.365583-6-tina.zhang@intel.com>
From:   Yanfei Xu <yanfei.xu@intel.com>
In-Reply-To: <20230707013441.365583-6-tina.zhang@intel.com>
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Hi Tina,

On 7/7/2023 9:34 AM, Tina Zhang wrote:
> @@ -33,9 +34,18 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma
>   		goto out;
>   	}
>   
> +	iommu_mm = kzalloc(sizeof(struct iommu_mm_data), GFP_KERNEL);
> +	if (!iommu_mm) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +	mm->iommu_mm = iommu_mm;
> +
>   	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL);
> -	if (ret < min)
> +	if (ret < min) {
> +		kfree(iommu_mm);
>   		goto out;

Once pasid allocation fails at this part, we should reassign the 
mm->iommu_mm back to default value, or it will keep a unavailable 
pointer, right?

Thanks,
Yanfei
> +	}
>   	mm_set_pasid(mm, ret);
>   	ret = 0;
>   out: