From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45751) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wnne2-0008Ib-SI for qemu-devel@nongnu.org; Fri, 23 May 2014 07:28:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wnndx-0002JH-Ui for qemu-devel@nongnu.org; Fri, 23 May 2014 07:28:14 -0400 Message-ID: <537F30C7.3010704@suse.de> Date: Fri, 23 May 2014 13:28:07 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1400821160-25258-1-git-send-email-aik@ozlabs.ru> <1400821160-25258-6-git-send-email-aik@ozlabs.ru> In-Reply-To: <1400821160-25258-6-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v6 5/7] vfio: Introduce VFIO address spaces List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , qemu-devel@nongnu.org Cc: Alex Williamson , qemu-ppc@nongnu.org, David Gibson On 23.05.14 06:59, Alexey Kardashevskiy wrote: > From: David Gibson > > The only model so far supported for VFIO passthrough devices is the model > usually used on x86, where all of the guest's RAM is mapped into the > (host) IOMMU and there is no IOMMU visible in the guest. > > This patch begins to relax this model, introducing the notion of a > VFIOAddressSpace. This represents a logical DMA address space which will > be visible to one or more VFIO devices by appropriate mapping in the (host) > IOMMU. Thus the currently global list of containers becomes local to > a VFIOAddressSpace, and we verify that we don't attempt to add a VFIO > group to multiple address spaces. > > For now, only one VFIOAddressSpace is created and used, corresponding to > main system memory, that will change in future patches. > > Signed-off-by: David Gibson > Signed-off-by: Alexey Kardashevskiy Don't we already have a DMA address space in the PCI bus? We could just use that one instead, no? Alex