Re: [Xen-devel] [question]: __gnttab_map_grant_ref() and iommu

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Wed, 2012-04-04 at 03:14 +0100, Mukesh Rathor wrote:
> I'm not able to figure why __gnttab_map_grant_ref() does PV iommu
> mappings for GNTMAP_host_map. Should it not check for GNTMAP_device_map
> and do for those only?

I don't know but perhaps it is because when the backend maps a foreign
page there is a reasonably high chance that it is eventually going to
end up passing that page to a hardware device (e.g. a physical NIC or
disk controller) for DMA and therefore the mapping must be reflected in
the IOMMU.

Ian.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel