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Cc:     baolu.lu@linux.intel.com, thomas.lendacky@amd.com, will@kernel.org,
        iommu@lists.linux-foundation.org, robin.murphy@arm.com
Subject: Re: [PATCH 0/2 v2] iommu: fix the failure of deferred attach for
 iommu attach device
To:     Lianbo Jiang <lijiang@redhat.com>, linux-kernel@vger.kernel.org
References: <20210119111616.12761-1-lijiang@redhat.com>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <e896bbd5-fdf3-ca04-b2f2-f1c7910f1ee0@linux.intel.com>
Date:   Tue, 19 Jan 2021 21:46:28 +0800
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On 2021/1/19 19:16, Lianbo Jiang wrote:
> This patchset is to fix the failure of deferred attach for iommu attach
> device, it includes the following two patches:
> 
> [1] [PATCH 1/2] dma-iommu: use static-key to minimize the impact in the fast-path
>      This is a prepared patch for the second one, move out the is_kdump_kernel()
>      check from iommu_dma_deferred_attach() to iommu_dma_init(), and use the
>      static-key in the fast-path to minimize the impact in the normal case.
> 
> [2] [PATCH 2/2] iommu: use the __iommu_attach_device() directly for deferred attach
>      Move the handling currently in iommu_dma_deferred_attach() into the
>      iommu core code so that it can call the __iommu_attach_device()
>      directly instead of the iommu_attach_device(). The external interface
>      iommu_attach_device() is not suitable for handling this situation.
> 
> Changes since v1:
> [1] use the __iommu_attach_device() directly for deferred attach
> [2] use static-key to minimize the impact in the fast-path
> 
> Lianbo Jiang (2):
>    dma-iommu: use static-key to minimize the impact in the fast-path
>    iommu: use the __iommu_attach_device() directly for deferred attach
> 
>   drivers/iommu/dma-iommu.c | 29 +++++++++++------------------
>   drivers/iommu/iommu.c     | 12 ++++++++++++
>   include/linux/iommu.h     |  2 ++
>   3 files changed, 25 insertions(+), 18 deletions(-)
> 

Good fix and improvement. For the patches in this series:

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

Best regards,
baolu