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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable 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 AAE65C2D0DB for ; Fri, 31 Jan 2020 17:51:17 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 7F57C206F0 for ; Fri, 31 Jan 2020 17:51:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F57C206F0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 49D61878AE; Fri, 31 Jan 2020 17:51:17 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rnQeztIavvsH; Fri, 31 Jan 2020 17:51:16 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id F128B878A4; Fri, 31 Jan 2020 17:51:15 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id D9A0AC0178; Fri, 31 Jan 2020 17:51:15 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id B0BD8C0171 for ; Fri, 31 Jan 2020 17:51:13 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 996AC20449 for ; Fri, 31 Jan 2020 17:51:13 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4T1c11FQShrj for ; Fri, 31 Jan 2020 17:51:12 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by silver.osuosl.org (Postfix) with ESMTPS id 9E9262043C for ; Fri, 31 Jan 2020 17:51:12 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jan 2020 09:51:06 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,386,1574150400"; d="scan'208";a="377409500" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga004.jf.intel.com with ESMTP; 31 Jan 2020 09:51:06 -0800 Date: Fri, 31 Jan 2020 09:56:21 -0800 From: Jacob Pan To: Alex Williamson Subject: Re: [PATCH 3/3] iommu/uapi: Add helper function for size lookup Message-ID: <20200131095621.6acec2fc@jacob-builder> In-Reply-To: <20200129144046.3f91e4c1@w520.home> References: <1580277724-66994-1-git-send-email-jacob.jun.pan@linux.intel.com> <1580277724-66994-4-git-send-email-jacob.jun.pan@linux.intel.com> <20200129144046.3f91e4c1@w520.home> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Cc: "Tian, Kevin" , Raj Ashok , Jean-Philippe Brucker , LKML , iommu@lists.linux-foundation.org, David Woodhouse , Jonathan Cameron X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Wed, 29 Jan 2020 14:40:46 -0700 Alex Williamson wrote: > On Tue, 28 Jan 2020 22:02:04 -0800 > Jacob Pan wrote: > > > IOMMU UAPI can be extended in the future by adding new > > fields at the end of each user data structure. Since we use > > a unified UAPI version for compatibility checking, a lookup > > function is needed to find the correct user data size to copy > > from user. > > > > This patch adds a helper function based on a 2D lookup with > > version and type as input arguments. > > > > Signed-off-by: Liu Yi L > > Signed-off-by: Jacob Pan > > --- > > drivers/iommu/iommu.c | 22 ++++++++++++++++++++++ > > include/linux/iommu.h | 6 ++++++ > > 2 files changed, 28 insertions(+) > > > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > index 7dd51c5d2ba1..9e5de9abebdf 100644 > > --- a/drivers/iommu/iommu.c > > +++ b/drivers/iommu/iommu.c > > @@ -1696,6 +1696,28 @@ int iommu_sva_unbind_gpasid(struct > > iommu_domain *domain, struct device *dev, } > > EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid); > > > > + > > +/** > > + * Maintain a UAPI version to user data structure size lookup for > > each > > + * API function types we support. e.g. bind guest pasid, cache > > invalidation. > > + * As data structures being extended with new members, the > > offsetofend() > > + * will identify the new sizes. > > + */ > > +const static int > > iommu_uapi_data_size[NR_IOMMU_UAPI_TYPE][IOMMU_UAPI_VERSION] = { > > + /* IOMMU_UAPI_BIND_GPASID */ > > + {offsetofend(struct iommu_gpasid_bind_data, vtd)}, > > + /* IOMMU_UAPI_CACHE_INVAL */ > > + {offsetofend(struct iommu_cache_invalidate_info, > > addr_info)}, > > + /* IOMMU_UAPI_PAGE_RESP */ > > + {offsetofend(struct iommu_page_response, code)}, > > +}; > > + > > +int iommu_uapi_get_data_size(int type, int version) > > +{ > > Seems like this is asking for a bounds check, > > if (type >= NR_IOMMU_UAPI_TYPE || version > IOMMU_UAPI_VERSION) > return -EINVAL; > yes, agreed. > If we add new types in future versions, I assume we'd back fill the > table with -EINVAL as well (rather than zero). Thanks, > right, if the array increase due to new types, the older version with the new type should be filled with -EINVAL. Let me document this in the rules of extensions. > Alex > > > + return iommu_uapi_data_size[type][version - 1]; > > +} > > +EXPORT_SYMBOL_GPL(iommu_uapi_get_data_size); > > + > > static void __iommu_detach_device(struct iommu_domain *domain, > > struct device *dev) > > { > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > > index 9718c109ea0a..416fe02160ba 100644 > > --- a/include/linux/iommu.h > > +++ b/include/linux/iommu.h > > @@ -500,6 +500,7 @@ extern int iommu_report_device_fault(struct > > device *dev, struct iommu_fault_event *evt); > > extern int iommu_page_response(struct device *dev, > > struct iommu_page_response *msg); > > +extern int iommu_uapi_get_data_size(int type, int version); > > > > extern int iommu_group_id(struct iommu_group *group); > > extern struct iommu_group *iommu_group_get_for_dev(struct device > > *dev); @@ -885,6 +886,11 @@ static inline int > > iommu_page_response(struct device *dev, return -ENODEV; > > } > > > > +static int iommu_uapi_get_data_size(int type, int version) > > +{ > > + return -ENODEV; > > +} > > + > > static inline int iommu_group_id(struct iommu_group *group) > > { > > return -ENODEV; > [Jacob Pan] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu