Messages in this thread | | | Date | Fri, 17 Feb 2023 11:47:52 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v2 0/6] iommu: Extend changing default domain to normal group |
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On Fri, Feb 17, 2023 at 05:47:30PM +0800, Lu Baolu wrote: > The IOMMU group sysfs interface allows users to change the default > domain of a group. The current implementation uses device_lock() to make > sure that the devices in the group are not bound to any driver and won't > be bound during the process of changing the default domain. In order to > avoid a possible deadlock caused by lock order of device_lock and > group->mutex, it limits the functionality to singleton groups only. > > The recently implemented DMA ownership framework can be applied here to > replace device_lock(). In addition, use group->mutex to ensure that the > iommu ops of the devices is always valid during the process of changing > default domain. > > With above replacement and enhancement, the device_lock() could be > removed and the singleton-group-only limitation could be removed. > > The whole series is also available on github: > https://github.com/LuBaolu/intel-iommu/commits/iommu-sysfs-default-domain-extension-v2 > > This series is on top of below series from Robin, > https://lore.kernel.org/linux-iommu/cover.1674753627.git.robin.murphy@arm.com/ > > Please help to review and suggest.
Given the overall situation, I think my suggestion to use arm_iommu_release_device() might be more short term practical.
Jason
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