From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9743C433FF for ; Thu, 8 Aug 2019 03:08:15 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B65C6216C8 for ; Thu, 8 Aug 2019 03:08:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B65C6216C8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46600 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvYml-0004ab-10 for qemu-devel@archiver.kernel.org; Wed, 07 Aug 2019 23:08:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36349) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvYmK-0003qM-4X for qemu-devel@nongnu.org; Wed, 07 Aug 2019 23:07:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hvYmJ-00067e-1I for qemu-devel@nongnu.org; Wed, 07 Aug 2019 23:07:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43620) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hvYmG-00065U-Lf; Wed, 07 Aug 2019 23:07:44 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1DE443001A6C; Thu, 8 Aug 2019 03:07:43 +0000 (UTC) Received: from x1.home (ovpn-116-99.phx2.redhat.com [10.3.116.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id 214585D71C; Thu, 8 Aug 2019 03:07:37 +0000 (UTC) Date: Wed, 7 Aug 2019 21:07:36 -0600 From: Alex Williamson To: Eric Auger Message-ID: <20190807210736.7703cdfd@x1.home> In-Reply-To: <20190711061857.13086-3-eric.auger@redhat.com> References: <20190711061857.13086-1-eric.auger@redhat.com> <20190711061857.13086-3-eric.auger@redhat.com> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Thu, 08 Aug 2019 03:07:43 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH-for-4.2 v3 2/5] memory: Add IOMMU_ATTR_VFIO_NESTED IOMMU memory region attribute X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org, peterx@redhat.com, qemu-arm@nongnu.org, pbonzini@redhat.com, eric.auger.pro@gmail.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 11 Jul 2019 08:18:54 +0200 Eric Auger wrote: > We introduce a new IOMMU Memory Region attribute, > IOMMU_ATTR_VFIO_NESTED that tells whether the virtual IOMMU > requires HW nested paging for VFIO integration. > > Current Intel virtual IOMMU device supports "Caching > Mode" and does not require 2 stages at physical level to be > integrated with VFIO. However SMMUv3 does not implement such > "caching mode" and requires to use HW nested paging. > > As such SMMUv3 is the first IOMMU device to advertise this > attribute. > > Signed-off-by: Eric Auger > --- > hw/arm/smmuv3.c | 12 ++++++++++++ > include/exec/memory.h | 3 ++- > 2 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c > index e96d5beb9a..384c02cb91 100644 > --- a/hw/arm/smmuv3.c > +++ b/hw/arm/smmuv3.c > @@ -1490,6 +1490,17 @@ static void smmuv3_notify_flag_changed(IOMMUMemoryRegion *iommu, > } > } > > +static int smmuv3_get_attr(IOMMUMemoryRegion *iommu, > + enum IOMMUMemoryRegionAttr attr, > + void *data) > +{ > + if (attr == IOMMU_ATTR_VFIO_NESTED) { > + *(bool *) data = true; > + return 0; > + } > + return -EINVAL; > +} > + > static void smmuv3_iommu_memory_region_class_init(ObjectClass *klass, > void *data) > { > @@ -1497,6 +1508,7 @@ static void smmuv3_iommu_memory_region_class_init(ObjectClass *klass, > > imrc->translate = smmuv3_translate; > imrc->notify_flag_changed = smmuv3_notify_flag_changed; > + imrc->get_attr = smmuv3_get_attr; > } > > static const TypeInfo smmuv3_type_info = { > diff --git a/include/exec/memory.h b/include/exec/memory.h > index a078cd033f..e477a630a8 100644 > --- a/include/exec/memory.h > +++ b/include/exec/memory.h > @@ -204,7 +204,8 @@ struct MemoryRegionOps { > }; > > enum IOMMUMemoryRegionAttr { > - IOMMU_ATTR_SPAPR_TCE_FD > + IOMMU_ATTR_SPAPR_TCE_FD, > + IOMMU_ATTR_VFIO_NESTED, > }; > > /** Why VFIO_NESTED vs simply NESTED? I figure any time we need to include "VFIO" in the descriptions of something, we're probably not describing the requirement correctly and it just becomes a meaningless tag that gets ignored outside of VFIO related things. If we're trying to describe an IOMMU MemoryRegion that supports dynamic faulting rather than requiring a replay to pre-populate it, then simply define that semantic rather than hand waving some vfio specific interaction. Thanks, Alex