From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 41jkTK3jjjzF2D1 for ; Sun, 5 Aug 2018 11:58:27 +1000 (AEST) Message-ID: <7fdcb1cb2900755a6534199a675483f60beb47fc.camel@kernel.crashing.org> Subject: Re: [RFC 0/4] Virtio uses DMA API for all devices From: Benjamin Herrenschmidt To: Christoph Hellwig , "Michael S. Tsirkin" Cc: Will Deacon , Anshuman Khandual , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, aik@ozlabs.ru, robh@kernel.org, joe@perches.com, elfring@users.sourceforge.net, david@gibson.dropbear.id.au, jasowang@redhat.com, mpe@ellerman.id.au, linuxram@us.ibm.com, haren@linux.vnet.ibm.com, paulus@samba.org, srikar@linux.vnet.ibm.com, robin.murphy@arm.com, jean-philippe.brucker@arm.com, marc.zyngier@arm.com Date: Sun, 05 Aug 2018 10:53:33 +1000 In-Reply-To: <20180804081500.GA1455@infradead.org> References: <20180801083639.GF26378@infradead.org> <26c1d3d50d8e081eed44fe9940fbefed34598cbd.camel@kernel.crashing.org> <20180802182959-mutt-send-email-mst@kernel.org> <82ccef6ec3d95ee43f3990a4a2d0aea87eb45e89.camel@kernel.crashing.org> <20180802200646-mutt-send-email-mst@kernel.org> <20180802225738-mutt-send-email-mst@kernel.org> <20180803070507.GA1344@infradead.org> <20180803221634-mutt-send-email-mst@kernel.org> <20180804081500.GA1455@infradead.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sat, 2018-08-04 at 01:15 -0700, Christoph Hellwig wrote: > b) a way to document in a virtio-related spec how the bus handles > dma for Ben's totally fucked up hypervisor. Without that there > is not way we'll get interoperable implementations. Christoph, this isn't a totally fucked up hypervisor. It's not even about the hypervisor itself, I mean seriously, man, can you at least bother reading what I described is going on with the security architecture ? Anyway, Michael is onto what could possibly be an alternative approach, by having us tell qemu to flip to iommu mode at secure VM boot time. Let's see where that leads. Cheers, Ben.