Re: [Xen-devel] [PATCH v4 23/33] xen/passthrough: iommu_deassign_device_dt: By default reassign device to nobody

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

On Thu, 2015-03-19 at 19:29 +0000, Julien Grall wrote:
> Currently, when the device is deassigned from a domain, we directly reassign
> to DOM0.
> 
> As the device may not have been correctly reset, this may lead to corruption 
> or
> expose some part of DOM0 memory. Also, we may have no way to reset some
> platform devices.
> 
> 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). Unfortunately there is no simple way to quiesce a buggy
> hardware. I think we could live with that for a first version of platform
> device passthrough.
> 
> DOM0 will have to issue an hypercall to assign the device to itself if it
> wants to use it.
> 
> Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
> Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>

Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>



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