Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Cc:     baolu.lu@linux.intel.com, iommu@lists.linux-foundation.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        suravee.suthikulpanit@amd.com, john.garry@huawei.com,
        dianders@chromium.org
Subject: Re: [PATCH v2 18/24] iommu: Express DMA strictness via the domain
 type
To:     Robin Murphy <robin.murphy@arm.com>, joro@8bytes.org,
        will@kernel.org
References: <cover.1627468308.git.robin.murphy@arm.com>
 <50bee17e9248ccfccb33a10238210d4ff4f4cf4d.1627468309.git.robin.murphy@arm.com>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <b479f1f9-ecf2-2798-2df8-ae3d4c06bc63@linux.intel.com>
Date:   Thu, 29 Jul 2021 15:13:15 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.11.0
MIME-Version: 1.0
In-Reply-To: <50bee17e9248ccfccb33a10238210d4ff4f4cf4d.1627468309.git.robin.murphy@arm.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi Robin,

On 7/28/21 11:58 PM, Robin Murphy wrote:
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 982545234cf3..eecb5657de69 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -136,6 +136,9 @@ static int __init iommu_subsys_init(void)
>   		}
>   	}
>   
> +	if (!iommu_default_passthrough() && !iommu_dma_strict)
> +		iommu_def_domain_type = IOMMU_DOMAIN_DMA_FQ;

iommu_dma_strict could be changed later by the vendor iommu driver via
iommu_set_dma_strict(). This seems not to be the right place to set
iommu_def_domain_type.

> +
>   	pr_info("Default domain type: %s %s\n",
>   		iommu_domain_type_str(iommu_def_domain_type),
>   		(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API) ?

Best regards,
baolu