Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 20 Oct 2014 14:37:17 -0700 | Subject | Re: [PATCH 2/5] vfio: introduce the VFIO_DMA_MAP_FLAG_NOEXEC flag |
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On Mon, Oct 13, 2014 at 6:09 AM, Antonios Motakis <a.motakis@virtualopensystems.com> wrote: > We introduce the VFIO_DMA_MAP_FLAG_NOEXEC flag to the VFIO dma map call, > and expose its availability via the capability VFIO_DMA_NOEXEC_IOMMU. > This way the user can control whether the XN flag will be set on the > requested mappings. The IOMMU_NOEXEC flag needs to be available for all > the IOMMUs of the container used.
Since you sent this to the linux-api list, I'll bite: what's the XN flag? I know what PROT_EXEC does when you mmap something, and I presume that vfio is mmappable, but I don't actually have any clue what this patch does.
I assume that this does not have anything to do with a non-CPU DMA master executing code in main memory, because that makes rather little sense. (Or maybe it really does, in which case: weird.)
--Andy
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