From: Baolu Lu <baolu.lu@linux.intel.com>
To: Yi Liu <yi.l.liu@intel.com>,
joro@8bytes.org, jgg@nvidia.com, kevin.tian@intel.com
Cc: baolu.lu@linux.intel.com, alex.williamson@redhat.com,
robin.murphy@arm.com, eric.auger@redhat.com, nicolinc@nvidia.com,
kvm@vger.kernel.org, chao.p.peng@linux.intel.com,
iommu@lists.linux.dev, zhenzhong.duan@intel.com,
jacob.jun.pan@intel.com
Subject: Re: [PATCH v2 10/12] iommu/vt-d: Return if no dev_pasid is found in domain
Date: Mon, 15 Apr 2024 14:04:15 +0800 [thread overview]
Message-ID: <ed73dfc1-a6a2-4a19-b716-7c1f245db75b@linux.intel.com> (raw)
In-Reply-To: <20240412081516.31168-11-yi.l.liu@intel.com>
On 4/12/24 4:15 PM, Yi Liu wrote:
> If no dev_pasid is found, it should be a problem of caller. So a WARN_ON
> is fine, but no need to go further as nothing to be cleanup and also it
> may hit unknown issue.
If "... it should be a problem of caller ...", then the check and WARN()
should be added in the caller instead of individual drivers.
>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
> drivers/iommu/intel/iommu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index df49aed3df5e..fff7dea012a7 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4614,8 +4614,9 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
> break;
> }
> }
> - WARN_ON_ONCE(!dev_pasid);
> spin_unlock_irqrestore(&dmar_domain->lock, flags);
> + if (WARN_ON_ONCE(!dev_pasid))
> + return;
The iommu core calls remove_dev_pasid op to tear down the translation on
a pasid and park it in a BLOCKED state. Since this is a must-be-
successful callback, it makes no sense to return before tearing down the
pasid table entry.
From the Intel iommu driver's perspective, the pasid devices have
already been tracked in the core, hence the dev_pasid is a duplicate and
will be removed later, so don't use it for other purposes.
In the end, perhaps we just need to remove the WARN_ON() from the code.
>
> domain_detach_iommu(dmar_domain, iommu);
> intel_iommu_debugfs_remove_dev_pasid(dev_pasid);
Best regards,
baolu
next prev parent reply other threads:[~2024-04-15 6:05 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-12 8:15 [PATCH v2 00/12] iommufd support pasid attach/replace Yi Liu
2024-04-12 8:15 ` [PATCH v2 01/12] iommu: Pass old domain to set_dev_pasid op Yi Liu
2024-04-15 5:32 ` Baolu Lu
2024-04-15 11:54 ` Jason Gunthorpe
2024-04-16 2:07 ` Baolu Lu
2024-04-16 17:47 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 02/12] iommu: Introduce a replace API for device pasid Yi Liu
2024-04-16 3:01 ` Duan, Zhenzhong
2024-04-16 9:18 ` Yi Liu
2024-04-17 8:44 ` Tian, Kevin
2024-04-17 12:17 ` Jason Gunthorpe
2024-04-18 0:08 ` Tian, Kevin
2024-04-29 13:55 ` Jason Gunthorpe
2024-04-30 5:00 ` Yi Liu
2024-04-30 12:26 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 03/12] iommufd: replace attach_fn with a structure Yi Liu
2024-04-12 8:15 ` [PATCH v2 04/12] iommufd: Support attach/replace hwpt per pasid Yi Liu
2024-04-29 13:56 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 05/12] iommu: Allow iommu driver to populate the max_pasids Yi Liu
2024-04-15 5:41 ` Baolu Lu
2024-04-17 8:49 ` Tian, Kevin
2024-04-20 5:45 ` Yi Liu
2024-04-22 11:52 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 06/12] iommufd/selftest: Add set_dev_pasid and remove_dev_pasid in mock iommu Yi Liu
2024-04-12 8:15 ` [PATCH v2 07/12] iommufd/selftest: Add a helper to get test device Yi Liu
2024-04-12 8:15 ` [PATCH v2 08/12] iommufd/selftest: Add test ops to test pasid attach/detach Yi Liu
2024-04-12 8:15 ` [PATCH v2 09/12] iommufd/selftest: Add coverage for iommufd " Yi Liu
2024-04-12 8:15 ` [PATCH v2 10/12] iommu/vt-d: Return if no dev_pasid is found in domain Yi Liu
2024-04-15 6:04 ` Baolu Lu [this message]
2024-04-16 9:21 ` Yi Liu
2024-04-17 2:30 ` Baolu Lu
2024-04-17 3:48 ` Yi Liu
2024-04-17 9:03 ` Tian, Kevin
2024-04-17 9:36 ` Yi Liu
2024-04-12 8:15 ` [PATCH v2 11/12] iommu/vt-d: Make intel_iommu_set_dev_pasid() to handle domain replacement Yi Liu
2024-04-17 9:19 ` Tian, Kevin
2024-04-17 9:35 ` Yi Liu
2024-04-17 12:19 ` Jason Gunthorpe
2024-04-12 8:15 ` [PATCH v2 12/12] iommu/vt-d: Add set_dev_pasid callback for nested domain Yi Liu
2024-04-17 9:25 ` Tian, Kevin
2024-04-30 9:19 ` Yi Liu
2024-05-06 7:42 ` Baolu Lu
2024-05-06 13:36 ` Jason Gunthorpe
2024-05-07 2:28 ` Yi Liu
2024-05-07 15:18 ` Jason Gunthorpe
2024-05-08 6:10 ` Yi Liu
2024-05-08 12:25 ` Jason Gunthorpe
2024-05-08 13:26 ` Yi Liu
2024-05-08 14:11 ` Jason Gunthorpe
2024-05-09 14:22 ` Liu, Yi L
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