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From: Baolu Lu <baolu.lu@linux.intel.com>
To: "Tian, Kevin" <kevin.tian@intel.com>,
	"iommu@lists.linux.dev" <iommu@lists.linux.dev>
Cc: baolu.lu@linux.intel.com, Joerg Roedel <joro@8bytes.org>,
	Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	"Liu, Yi L" <yi.l.liu@intel.com>,
	"Pan, Jacob jun" <jacob.jun.pan@intel.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/7] iommu/vt-d: Use device_block_translation() in dev_attach error path
Date: Sat, 5 Nov 2022 10:59:08 +0800	[thread overview]
Message-ID: <3dac436c-29e1-de3d-85f3-67e8af608124@linux.intel.com> (raw)
In-Reply-To: <f6ee3ad3-0e75-2bc0-d03d-c2456ed6620a@linux.intel.com>

On 2022/11/5 10:09, Baolu Lu wrote:
>>
>> btw this change is partial. @attach_dev still calls 
>> iommu_enable_pci_caps()
>> which always tries to enable PCI capabilities w/o checking whether they
>> have been enabled or not. Then user will hit -EBUSY when related PCI
>> helpers are called.
> 
> Good catch!
> 
> How about moving iommu_enable/disable_pci_caps() into
> iommu_probe/release_device() path? I may look into details if there's no
> significant arch gaps.

After reconsideration, it seems that this is not a feasible solution.
This changes the order in which PCI devices enable DMA.In addition, for
the kdump kernel, this is not feasible because there may be on-going DMA
on the device.

Perhaps I can make the iommu_enable_pci_caps() reentrant.

Best regards,
baolu

  reply	other threads:[~2022-11-05  2:59 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-03  5:53 [PATCH 0/7] iommu/vt-d: Some cleanups Lu Baolu
2022-11-03  5:53 ` [PATCH 1/7] iommu/vt-d: Allocate pasid table in device probe path Lu Baolu
2022-11-04  2:06   ` Tian, Kevin
2022-11-05  1:09     ` Baolu Lu
2022-11-05  1:33       ` Tian, Kevin
2022-11-03  5:53 ` [PATCH 2/7] iommu/vt-d: Add blocking domain support Lu Baolu
2022-11-04  2:11   ` Tian, Kevin
2022-11-05  1:54     ` Baolu Lu
2022-11-03  5:53 ` [PATCH 3/7] iommu/vt-d: Use device_block_translation() in dev_attach error path Lu Baolu
2022-11-04  2:18   ` Tian, Kevin
2022-11-05  2:09     ` Baolu Lu
2022-11-05  2:59       ` Baolu Lu [this message]
2022-11-03  5:53 ` [PATCH 4/7] iommu/vt-d: Fold dmar_remove_one_dev_info() into its caller Lu Baolu
2022-11-03  5:53 ` [PATCH 5/7] iommu/vt-d: Rename domain_add_dev_info() Lu Baolu
2022-11-03  5:53 ` [PATCH 6/7] iommu/vt-d: Remove unnecessary domain_context_mapped() Lu Baolu
2022-11-04  2:19   ` Tian, Kevin
2022-11-03  5:53 ` [PATCH 7/7] iommu/vt-d: Use real field for indication of first level Lu Baolu
2022-11-04  2:20   ` Tian, Kevin

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