| Subject | Re: [PATCH v2 22/24] iommu: Allow enabling non-strict mode dynamically | From | John Garry <> | Date | Fri, 30 Jul 2021 10:24:24 +0100 |
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On 28/07/2021 16:58, Robin Murphy wrote: > Allocating and enabling a flush queue is in fact something we can > reasonably do while a DMA domain is active, without having to rebuild it > from scratch. Thus we can allow a strict -> non-strict transition from > sysfs without requiring to unbind the device's driver, which is of > particular interest to users who want to make selective relaxations to > critical devices like the one serving their root filesystem. > > Disabling and draining a queue also seems technically possible to > achieve without rebuilding the whole domain, but would certainly be more > involved. Furthermore there's not such a clear use-case for tightening > up security*after* the device may already have done whatever it is that > you don't trust it not to do, so we only consider the relaxation case. > > Signed-off-by: Robin Murphy<robin.murphy@arm.com>
Reviewed-by: John Garry <john.garry@huawei.com>
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