On Tue, 2010-06-08 at 14:21 -0700, Tom Lyon wrote: > +The VFIO_DMA_MASK ioctl is used to set the maximum permissible DMA address > +(device dependent). It takes a single unsigned 64 bit integer as an argument. > +This call also has the side effect of enabling PCI bus mastership. Hi Tom, This interface doesn't make sense for the MAP_IOVA user. Especially in qemu, we have no idea what the DMA mask is for the device we're assigning. It doesn't really matter though because the guest will use bounce buffers internally once it loads the device specific drivers and discovers the DMA mask. This only seems relevant if we're using a DMA_MAP call that gets to pick the dmaaddr, so I'd propose we only make this a required call for that interface, and create a separate ioctl for actually enabling bus master. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
