Messages in this thread | | | Date | Sat, 18 Feb 2023 15:31:47 +0800 | Subject | Re: [PATCH v2 0/6] iommu: Extend changing default domain to normal group | From | Baolu Lu <> |
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On 2/17/23 11:47 PM, Jason Gunthorpe wrote: > 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.
Yes. Fair enough.
Best regards, baolu
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