Messages in this thread | | | Subject | Re: [PATCH 2/2] arm/xen: Don't use xen DMA ops when the device is protected by an IOMMU | From | Ian Campbell <> | Date | Thu, 20 Feb 2014 16:35:59 +0000 |
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On Thu, 2014-02-20 at 16:21 +0000, Julien Grall wrote: > Only Xen is able to know if a device can safely avoid to use xen-swiotlb. > This patch introduce a new property "protected-devices" for the hypervisor > node which list device which the IOMMU are been correctly programmed by Xen. > > During Linux boot, Xen specific code will create an hash table which > contains all these devices. The hash table will be used in need_xen_dma_ops > to check if the Xen DMA ops needs to be used for the current device.
Is it out of the question to find a field within struct device itself to store this e.g. in struct device_dma_parameters perhaps and avoid the need for a hashtable lookup.
device->iommu_group might be another option, if we can create our own group?
Ian.
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