From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37028) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bID7r-0002yp-8X for qemu-devel@nongnu.org; Wed, 29 Jun 2016 06:53:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bID7m-0006zI-BT for qemu-devel@nongnu.org; Wed, 29 Jun 2016 06:53:47 -0400 Received: from mail-wm0-x22f.google.com ([2a00:1450:400c:c09::22f]:36808) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bID7m-0006zE-3r for qemu-devel@nongnu.org; Wed, 29 Jun 2016 06:53:42 -0400 Received: by mail-wm0-x22f.google.com with SMTP id f126so175725540wma.1 for ; Wed, 29 Jun 2016 03:53:41 -0700 (PDT) Sender: Paolo Bonzini References: <20160615154203.32658.82724.stgit@gimli.home> <20160628084924.43566423@t450s.home> From: Paolo Bonzini Message-ID: <33a19cf3-13dc-6ce0-7a68-8cfdef7f0357@redhat.com> Date: Wed, 29 Jun 2016 12:53:39 +0200 MIME-Version: 1.0 In-Reply-To: <20160628084924.43566423@t450s.home> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 0/2] memory/intel_iommu: Generate error for incompatible usage List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson , mst@redhat.com Cc: qemu-devel@nongnu.org, aik@ozlabs.ru, bd.aviv@gmail.com, peterx@redhat.com, marcel@redhat.com, david@gibson.dropbear.id.au On 28/06/2016 16:49, Alex Williamson wrote: > Paolo & Michael, > > Any comments on this series? I think we need Paolo's ack for the memory > changes and either of your ack for hw/i386/. I'm happy to pull this > through my tree with your approval though. Thanks, I think I already acked the callbacks, in any case the patches look good. Paolo > Alex > > On Wed, 15 Jun 2016 09:56:03 -0600 > Alex Williamson wrote: > >> VT-d emulation is currently incompatible with device assignment due >> to intel_iommu's lack of support for memory_region_notify_iommu(). >> Alexey has proposed a nice addition to the MemoryRegionIOMMUOps >> structure that adds callbacks when the first iommu notifier is >> registered and the last is removed. For POWER this will allow them >> to switch the view of the iommu depending on whether anyone in >> userspace is watching. For VT-d I expect that eventually we'll use >> these callbacks to enable and disable code paths so that we avoid >> notifier overhead when there are no registered notifiy-ees. For now, >> we don't support calling memory_region_notify_iommu(), so this >> signals an incompatible hardware configuration. If we choose to make >> CM=0 a user selectable option, something like this might continue to >> be useful if we only support notifies via invalidations rather than >> full VT-d data structure shadowing. >> >> Even though we're currently working on enabling users like vfio-pci >> with VT-d, I believe this is correct for the current state of things. >> We might even want to consider this stable for v2.6.x so that >> downstreams pick it up to avoid incompatible configurations. >> >> Alexey, I hope I'm not stepping on your toes by extracting this >> from your latest patch series. Please let us know whether you >> approve. Thanks, >> >> Alex >> >> --- >> >> Alex Williamson (1): >> intel_iommu: Throw hw_error on notify_started >> >> Alexey Kardashevskiy (1): >> memory: Add MemoryRegionIOMMUOps.notify_started/stopped callbacks >> >> >> hw/i386/intel_iommu.c | 12 ++++++++++++ >> hw/vfio/common.c | 5 +++-- >> include/exec/memory.h | 8 +++++++- >> memory.c | 10 +++++++++- >> 4 files changed, 31 insertions(+), 4 deletions(-) >