From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41544) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wi3w7-0007RG-Lx for qemu-devel@nongnu.org; Wed, 07 May 2014 11:39:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wi3w1-00039O-G6 for qemu-devel@nongnu.org; Wed, 07 May 2014 11:39:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:20851) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wi3w1-000397-8g for qemu-devel@nongnu.org; Wed, 07 May 2014 11:39:05 -0400 Message-ID: <536A5389.1020809@redhat.com> Date: Wed, 07 May 2014 17:38:49 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1399475403-5408-1-git-send-email-stefano.stabellini@eu.citrix.com> <536A4FBB.50105@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL 1/7] exec: Limit translation limiting in address_space_translate to xen List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Olaf Hering , "xen-devel@lists.xensource.com Devel" , Stefano Stabellini , Alexey Kardashevskiy , QEMU Developers , Anthony Liguori , Anthony PERARD Il 07/05/2014 17:32, Peter Maydell ha scritto: > > Regarding fixing callers, a known one is virtio-scsi which is a bug and on > > my todo list. But another is VFIO, which cannot accept truncation if the > > IOMMU page size is greater than TARGET_PAGE_SIZE. > > The API can't simultaneously allow the implementation to truncate > and guarantee to the caller that we don't truncate, so one of these > has to change, surely? We can provide a function to return the truncation granularity, and add to VFIO a check that will prevent using VFIO together with Xen. Paolo From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PULL 1/7] exec: Limit translation limiting in address_space_translate to xen Date: Wed, 07 May 2014 17:38:49 +0200 Message-ID: <536A5389.1020809@redhat.com> References: <1399475403-5408-1-git-send-email-stefano.stabellini@eu.citrix.com> <536A4FBB.50105@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Peter Maydell Cc: Olaf Hering , "xen-devel@lists.xensource.com Devel" , Stefano Stabellini , Alexey Kardashevskiy , QEMU Developers , Anthony Liguori , Anthony PERARD List-Id: xen-devel@lists.xenproject.org Il 07/05/2014 17:32, Peter Maydell ha scritto: > > Regarding fixing callers, a known one is virtio-scsi which is a bug and on > > my todo list. But another is VFIO, which cannot accept truncation if the > > IOMMU page size is greater than TARGET_PAGE_SIZE. > > The API can't simultaneously allow the implementation to truncate > and guarantee to the caller that we don't truncate, so one of these > has to change, surely? We can provide a function to return the truncation granularity, and add to VFIO a check that will prevent using VFIO together with Xen. Paolo