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If we want to > make it a policy, it should be enforced by code, but creating that > policy based on a difficulty in supporting that mode with iommufd isn't > great. On the other hand adding code to allow device FDs in the hot reset path that is never used and never tested isn't great either.. hot-reset does work for DPDK, it just doesn't work in the case where DPDK would have many VFIO devices open and they have overlapping device sets. Which, again, is something it doesn't do. IMHO we should leave it out of the kernel and wait for a no-iommu user to come forward that wants hot-reset of many devices. Then we can add and test the device FD part. Most likely such a thing will never come at this point. Jason