On Wed, Jan 30, 2019 at 08:44:27AM +0100, Christoph Hellwig wrote: > On Tue, Jan 29, 2019 at 09:36:08PM -0500, Michael S. Tsirkin wrote: > > This has been discussed ad nauseum. virtio is all about compatibility. > > Losing a couple of lines of code isn't worth breaking working setups. > > People that want "just use DMA API no tricks" now have the option. > > Setting a flag in a feature bit map is literally a single line > > of code in the hypervisor. So stop pushing for breaking working > > legacy setups and just fix it in the right place. > > I agree with the legacy aspect. What I am missing is an extremely > strong wording that says you SHOULD always set this flag for new > hosts, including an explanation why. So as far as power is concerned, IIUC the issue they are struggling with is that some platforms do not support pass-through mode in the emulated IOMMU. Disabling PLATFORM_ACCESS is so far a way around that, unfortunately just for virtio devices. I would like virtio-iommu to be able to address that need as well. -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
