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Date:   Mon, 25 Jul 2022 08:39:23 +0100
From:   Jean-Philippe Brucker <jean-philippe@linaro.org>
To:     Baolu Lu <baolu.lu@linux.intel.com>
Cc:     Jason Gunthorpe <jgg@nvidia.com>, Joerg Roedel <joro@8bytes.org>,
        Christoph Hellwig <hch@infradead.org>,
        Kevin Tian <kevin.tian@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        Eric Auger <eric.auger@redhat.com>,
        Liu Yi L <yi.l.liu@intel.com>,
        Jacob jun Pan <jacob.jun.pan@intel.com>,
        Zhangfei Gao <zhangfei.gao@linaro.org>,
        Zhu Tony <tony.zhu@intel.com>, iommu@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v10 08/12] iommu/sva: Refactoring
 iommu_sva_bind/unbind_device()
Message-ID: <Yt5IqyZw/Sa6Ck5t@myrica>
References: <20220705050710.2887204-1-baolu.lu@linux.intel.com>
 <20220705050710.2887204-9-baolu.lu@linux.intel.com>
 <20220723142650.GH79279@nvidia.com>
 <bffb6e2d-d310-49b9-0725-37ab4263c22d@linux.intel.com>
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On Sun, Jul 24, 2022 at 09:48:15PM +0800, Baolu Lu wrote:
> /*
>  * iommu_detach_device_pasid() - Detach the domain from pasid of device
>  * @domain: the iommu domain.
>  * @dev: the attached device.
>  * @pasid: the pasid of the device.
>  *
>  * The @domain must have been attached to @pasid of the @dev with
>  * iommu_detach_device_pasid().
>  */
> void iommu_detach_device_pasid(struct iommu_domain *domain, struct device
> *dev,
> 			       ioasid_t pasid)
> {
> 	struct iommu_group *group = iommu_group_get(dev);
> 	struct group_pasid *param;
> 
> 	mutex_lock(&group->mutex);
> 	domain->ops->set_dev_pasid(group->blocking_domain, dev, pasid);

Please also pass the old domain to this detach() function, so that the
IOMMU driver doesn't have to keep track of them internally.

In addition to clearing contexts, detach() also needs to invalidate TLBs,
and for that the SMMU driver needs to know the old ASID (!= PASID) that
was used by the context descriptor.

Thanks,
Jean