On Tue, 2013-03-19 at 20:08 -0700, H. Peter Anvin wrote: > On 03/19/2013 07:48 PM, H. Peter Anvin wrote: > > On 03/19/2013 06:28 PM, Matthew Garrett wrote: > >> Mm. The question is whether we can reliably determine the ranges a > device should be able to access without having to trust userspace > (and, ideally, without having to worry about whether iommu vendors > have done their job). It's pretty important for PCI passthrough, so we > do need to care. > > > > It is actually very simple: the device should be able to DMA into/out of: > > > > 1. pinned pages > > 2. owned by the process controlling the device > > > > ... and nothing else. > > > > The "pinning" process needs to involve a call to the kernel to process > the page for DMA (pinning the page and opening it in the iommu) and > return a transaction address, of course. > > I think we have the interface for that in vfio, but I haven't followed > that work. Yes, vfio does this and is meant to provide a secure-boot-friendly PCI passthrough interface. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
