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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 704B7C2D0DB for ; Wed, 29 Jan 2020 21:40:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BEB9206F0 for ; Wed, 29 Jan 2020 21:40:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DQmNA8ZE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726620AbgA2Vk5 (ORCPT ); Wed, 29 Jan 2020 16:40:57 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:28256 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726222AbgA2Vk5 (ORCPT ); Wed, 29 Jan 2020 16:40:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580334055; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8pjsr+8GgeZRx08ogbJ32q6tJdvfyOSXMDX5qngbmsc=; b=DQmNA8ZEhs7sdGr0Bzf29Ar8KJ/RnSYZwakAkdsbBW4NHJDznSIOGtH+NpYx5uB4jUlcXu sXyCmjAfljWqI1upTaf6OA1SXCbqJ0YcDCfhLwOgrO9hnn95Qu++9eVMXWzP2zYbNtdnwM vXVoAheN5Kx+PVznQ0ktO7V/dzNLYNk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-26-BKFe_yzwM1CxZrLAq07h-g-1; Wed, 29 Jan 2020 16:40:53 -0500 X-MC-Unique: BKFe_yzwM1CxZrLAq07h-g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2ECCA18A6EC1; Wed, 29 Jan 2020 21:40:51 +0000 (UTC) Received: from w520.home (ovpn-116-28.phx2.redhat.com [10.3.116.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id BE8F687B07; Wed, 29 Jan 2020 21:40:47 +0000 (UTC) Date: Wed, 29 Jan 2020 14:40:46 -0700 From: Alex Williamson To: Jacob Pan Cc: iommu@lists.linux-foundation.org, LKML , "Lu Baolu" , Joerg Roedel , David Woodhouse , "Yi Liu" , "Tian, Kevin" , Raj Ashok , "Christoph Hellwig" , Jean-Philippe Brucker , Jonathan Cameron , Eric Auger Subject: Re: [PATCH 3/3] iommu/uapi: Add helper function for size lookup Message-ID: <20200129144046.3f91e4c1@w520.home> In-Reply-To: <1580277724-66994-4-git-send-email-jacob.jun.pan@linux.intel.com> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; If we add new types in future versions, I assume we'd back fill the table with -EINVAL as well (rather than zero). Thanks, 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;