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Message-ID: <175e0393-735f-3dde-b086-fb5bc514ddee@linux.intel.com>
Date:   Sun, 21 May 2023 14:29:04 +0800
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Cc:     baolu.lu@linux.intel.com, Robin Murphy <robin.murphy@arm.com>,
        Will Deacon <will@kernel.org>,
        David Woodhouse <dwmw2@infradead.org>,
        Raj Ashok <ashok.raj@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>,
        "Yu, Fenghua" <fenghua.yu@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        "Zanussi, Tom" <tom.zanussi@intel.com>,
        narayan.ranganathan@intel.com
Subject: Re: [PATCH v6 4/4] dmaengine/idxd: Re-enable kernel workqueue under
 DMA API
Content-Language: en-US
To:     Jacob Pan <jacob.jun.pan@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>, iommu@lists.linux.dev,
        Jason Gunthorpe <jgg@nvidia.com>,
        Joerg Roedel <joro@8bytes.org>, dmaengine@vger.kernel.org,
        vkoul@kernel.org
References: <20230519203223.2777255-1-jacob.jun.pan@linux.intel.com>
 <20230519203223.2777255-5-jacob.jun.pan@linux.intel.com>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <20230519203223.2777255-5-jacob.jun.pan@linux.intel.com>
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On 5/20/23 4:32 AM, Jacob Pan wrote:
> Kernel workqueues were disabled due to flawed use of kernel VA and SVA
> API. Now that we have the support for attaching PASID to the device's
> default domain and the ability to reserve global PASIDs from SVA APIs,
> we can re-enable the kernel work queues and use them under DMA API.
> 
> We also use non-privileged access for in-kernel DMA to be consistent
> with the IOMMU settings. Consequently, interrupt for user privilege is
> enabled for work completion IRQs.
> 
> Link:https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/
> Reviewed-by: Dave Jiang<dave.jiang@intel.com>
> Reviewed-by: Fenghua Yu<fenghua.yu@intel.com>
> Signed-off-by: Jacob Pan<jacob.jun.pan@linux.intel.com>

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu