From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 16FDC90 for ; Mon, 26 Oct 2015 05:04:53 +0000 (UTC) Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5FE1B90 for ; Mon, 26 Oct 2015 05:04:52 +0000 (UTC) Date: Mon, 26 Oct 2015 06:04:50 +0100 From: Joerg Roedel To: David Woodhouse Message-ID: <20151026050450.GF27420@8bytes.org> References: <1445833878.3405.24.camel@infradead.org> <20151026044350.GE27420@8bytes.org> <1445834882.3405.30.camel@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1445834882.3405.30.camel@infradead.org> Cc: Paolo Bonzini , m.smarduch@samsung.com, "ksummit-discuss@lists.linuxfoundation.org" Subject: Re: [Ksummit-discuss] Short topic: virtio vs IOMMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Oct 26, 2015 at 01:48:02PM +0900, David Woodhouse wrote: > It would be useful to have an emulated IOMMU, full stop. And yeah, it > might actually make sense to *start* by using it for purely virtual > devices, [...] Sure, I think this is what qemu provides already, except for the virtio devices (which are also emulated). I think it would be cool to have virtio translated by the emulated iommu too (at least optional). > [...] and then graduate to doing it for passthrough (which will > finally mean we can stop having to pin *all* guest memory the moment we > assign a device, and we only have to pin those pages which are > referenced from the IOMMU page tables). Good point, havn't thought of that yet. But getting rid of the excessive pinning this way would be really great. Joerg