Messages in this thread | | | Date | Wed, 19 Oct 2022 08:49:19 +0800 | Subject | Re: [PATCH 0/2] iommu/vt-d: Fix lockdep splat in intel_iommu_init() | From | Baolu Lu <> |
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On 9/27/22 1:31 PM, Lu Baolu wrote: > Hi folks, > > As commit c919739ce472 ("iommu/vt-d: Handle race between registration > and device probe") highlights, a lockdep splat issue happens after > moving iommu probing device process into iommu_device_register(). > > This is due to a conflict that get_resv_regions wants hold the > dmar_global_lock, but it's also possible to be called from within a > section where intel_iommu_init() already holds the lock. > > Historically, before commit 5f64ce5411b46 ("iommu/vt-d: Duplicate > iommu_resv_region objects per device list"), the rcu_lock is used in > get_resv_regions. This commit converted it to dmar_global_lock in order > to allowing sleeping in iommu_alloc_resv_region(). > > This aims to fix the lockdep issue by making iommu_alloc_resv_region() > available in critical section and rolling dmar_global_lock back to rcu > lock in get_resv_regions of the Intel IOMMU driver. > > Best regards, > baolu > > Lu Baolu (2): > iommu: Add gfp parameter to iommu_alloc_resv_region > iommu/vt-d: Use rcu_lock in get_resv_regions
Patches has been queued for v6.1.
https://lore.kernel.org/linux-iommu/20221019004447.4563-1-baolu.lu@linux.intel.com/
Best regards, baolu
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