From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?Q?Llu=C3=ADs_Vilanova?= Subject: Re: Direct guest device access from nested guest Date: Wed, 28 Aug 2013 21:12:36 +0300 Message-ID: <87ppsxelbf.fsf@fimbulvetr.bsc.es> References: <87sixtsxdj.fsf@fimbulvetr.bsc.es> <521E29F5.3070000@siemens.com> Mime-Version: 1.0 Content-Type: text/plain Cc: qemu-devel@nongnu.org, kvm To: Jan Kiszka Return-path: In-Reply-To: <521E29F5.3070000@siemens.com> (Jan Kiszka's message of "Wed, 28 Aug 2013 18:48:53 +0200") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org Jan Kiszka writes: [...] >> Is it possible to give a nested guest direct access to a device on the guest? >> (more specifically, an AHCI controller). > Nope, we are lacking support for emulating or (securely) forwarding > VT-d/IOMMU features to the first level guest. Would be cool to have, > just not yet there. But I've talked to Intel people recently, and they > are considering to support some nested VT-d with KVM. Thanks a lot. I've been told there's some patches floating around to add such support, but I suppose they've been long outdated and only work as POCs. Lluis -- "And it's much the same thing with knowledge, for whenever you learn something new, the whole world becomes that much richer." -- The Princess of Pure Reason, as told by Norton Juster in The Phantom Tollbooth From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58290) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VEkEc-0006Pt-6g for qemu-devel@nongnu.org; Wed, 28 Aug 2013 14:12:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VEkEU-0003yg-45 for qemu-devel@nongnu.org; Wed, 28 Aug 2013 14:12:50 -0400 Received: from roura.ac.upc.es ([147.83.33.10]:46830) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VEkET-0003yW-OU for qemu-devel@nongnu.org; Wed, 28 Aug 2013 14:12:42 -0400 From: =?utf-8?Q?Llu=C3=ADs_Vilanova?= In-Reply-To: <521E29F5.3070000@siemens.com> (Jan Kiszka's message of "Wed, 28 Aug 2013 18:48:53 +0200") References: <87sixtsxdj.fsf@fimbulvetr.bsc.es> <521E29F5.3070000@siemens.com> Date: Wed, 28 Aug 2013 21:12:36 +0300 Message-ID: <87ppsxelbf.fsf@fimbulvetr.bsc.es> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] Direct guest device access from nested guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: qemu-devel@nongnu.org, kvm Jan Kiszka writes: [...] >> Is it possible to give a nested guest direct access to a device on the guest? >> (more specifically, an AHCI controller). > Nope, we are lacking support for emulating or (securely) forwarding > VT-d/IOMMU features to the first level guest. Would be cool to have, > just not yet there. But I've talked to Intel people recently, and they > are considering to support some nested VT-d with KVM. Thanks a lot. I've been told there's some patches floating around to add such support, but I suppose they've been long outdated and only work as POCs. Lluis -- "And it's much the same thing with knowledge, for whenever you learn something new, the whole world becomes that much richer." -- The Princess of Pure Reason, as told by Norton Juster in The Phantom Tollbooth