[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC 12/19] xen/passthrough: iommu_deassign_device_dt: By default reassign device to nobody
On 07/03/2014 01:53 PM, Ian Campbell wrote: > On Thu, 2014-07-03 at 13:07 +0100, Julien Grall wrote: >>>> If Xen reassigns the device to "nobody", it may receive some global/context >>>> fault because the transaction has failed (indeed the context has been >>>> marked invalid). >>> >>> Can you describe here what happen in this case (I presume Xen tears down >>> the iommu to quiesce them somehow?) >> >> The SMMU drivers will mark the different Context Bank, S2CR, SMR as >> invalid. If the device is attempt to access the memory then, we will >> receive an interrupt in Xen. >> >> Actually it's only happen once, if the device is still enabled when the >> domain is shutdown. > > My concern was with getting a storm of such interrupts after this point. > If it only happens once and any subsequent ones are damped by some means > then great. I guess, it can happen with a buggy device trying to access memory alone. But I don't think we should care about this case. Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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