On Tue, Nov 22, 2016 at 05:22:38PM +0200, Michael S. Tsirkin wrote: > The issue is it's a (potential) security hole, not a slowdown. How? Because the bounce buffers will be unencrypted and someone might intercept them? > To disable unsecure things. If someone enables SEV one might have an > expectation of security. Might help push vendors to do the right thing > as a side effect. Ok, you're looking at the SEV-cloud-multiple-guests aspect. Right, that makes sense. I guess for SEV we should even flip the logic: disable such devices by default and an opt-in option to enable them and issue a big fat warning. I'd even want to let the guest users know that they're on a system which cannot give them encrypted DMA to some devices... -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html