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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B76CCC3A5A1 for ; Thu, 22 Aug 2019 15:20:56 +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 8BCCF2089E for ; Thu, 22 Aug 2019 15:20:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8BCCF2089E 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]:44406 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0otT-0008Nm-HV for qemu-devel@archiver.kernel.org; Thu, 22 Aug 2019 11:20:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44026) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0ooQ-0005mR-Gf for qemu-devel@nongnu.org; Thu, 22 Aug 2019 11:15:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i0ooP-0007Hg-CQ for qemu-devel@nongnu.org; Thu, 22 Aug 2019 11:15:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57976) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i0ooL-0007C9-Bj; Thu, 22 Aug 2019 11:15:37 -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 A041010F23E0; Thu, 22 Aug 2019 15:15:36 +0000 (UTC) Received: from [10.36.116.105] (ovpn-116-105.ams2.redhat.com [10.36.116.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7E2435D6A7; Thu, 22 Aug 2019 15:15:30 +0000 (UTC) To: Alex Williamson References: <20190711061857.13086-1-eric.auger@redhat.com> <20190711061857.13086-3-eric.auger@redhat.com> <20190807210736.7703cdfd@x1.home> From: Auger Eric Message-ID: <98b29df1-ddf0-dcb8-8f56-0efdd5760f2e@redhat.com> Date: Thu, 22 Aug 2019 17:15:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190807210736.7703cdfd@x1.home> Content-Type: text/plain; charset=utf-8 Content-Language: en-US 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-4.6.2 (mx1.redhat.com [10.5.110.66]); Thu, 22 Aug 2019 15:15:36 +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" Hi Alex, Peter, On 8/8/19 5:07 AM, Alex Williamson wrote: > 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, I replaced it by IOMMU_ATTR_HW_NESTED_PAGING instead. Thanks Eric > > Alex >