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=-11.5 required=3.0 tests=BAYES_00, 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 635F7C433E0 for ; Tue, 21 Jul 2020 01:45:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40A372072E for ; Tue, 21 Jul 2020 01:45:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726731AbgGUBpu (ORCPT ); Mon, 20 Jul 2020 21:45:50 -0400 Received: from mga17.intel.com ([192.55.52.151]:56794 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725954AbgGUBpt (ORCPT ); Mon, 20 Jul 2020 21:45:49 -0400 IronPort-SDR: gfO2w3nz5I7iUFtj1/p6SmRbBe+Cn+55w39LJTf7cXDzokuRCcHywkIO+CjYqVtyegNOFXf8lT qkkSAZUhW7cg== X-IronPort-AV: E=McAfee;i="6000,8403,9688"; a="130121533" X-IronPort-AV: E=Sophos;i="5.75,377,1589266800"; d="scan'208";a="130121533" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2020 18:45:48 -0700 IronPort-SDR: KRaxwk92I+jel9tcLEJ2Nj2mexLNFK2VnXAavZ9QcNJIPrp9Lbx2Yh71ym9Ka0GtwL3+p924nn p5m1lOXlOLCg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,377,1589266800"; d="scan'208";a="326229072" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by FMSMGA003.fm.intel.com with ESMTP; 20 Jul 2020 18:45:48 -0700 Date: Mon, 20 Jul 2020 18:52:33 -0700 From: Jacob Pan To: Auger Eric Cc: iommu@lists.linux-foundation.org, LKML , Joerg Roedel , Alex Williamson , Lu Baolu , David Woodhouse , Yi Liu , "Tian, Kevin" , Raj Ashok , Christoph Hellwig , Jean-Philippe Brucker , Jonathan Corbet , jacob.jun.pan@linux.intel.com Subject: Re: [PATCH v5 2/5] iommu/uapi: Add argsz for user filled data Message-ID: <20200720185233.3e5841c1@jacob-builder> In-Reply-To: <1538ec69-62a2-ea04-0870-a583fc63a2bf@redhat.com> References: <1594925117-64892-1-git-send-email-jacob.jun.pan@linux.intel.com> <1594925117-64892-3-git-send-email-jacob.jun.pan@linux.intel.com> <1538ec69-62a2-ea04-0870-a583fc63a2bf@redhat.com> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 17 Jul 2020 15:44:23 +0200 Auger Eric wrote: > Hi Jacob, > > On 7/16/20 8:45 PM, Jacob Pan wrote: > > As IOMMU UAPI gets extended, user data size may increase. To support > > backward compatibiliy, this patch introduces a size field to each > > UAPI data structures. It is *always* the responsibility for the > > user to fill in the correct size. Padding fields are adjusted to > > ensure 8 byte alignment. > > > > Specific scenarios for user data handling are documented in: > > Documentation/userspace-api/iommu.rst > > > > Signed-off-by: Liu Yi L > > Signed-off-by: Jacob Pan > > --- > > include/uapi/linux/iommu.h | 12 +++++++++--- > > 1 file changed, 9 insertions(+), 3 deletions(-) > > > > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h > > index e907b7091a46..d5e9014f690e 100644 > > --- a/include/uapi/linux/iommu.h > > +++ b/include/uapi/linux/iommu.h > > @@ -135,6 +135,7 @@ enum iommu_page_response_code { > > > > /** > > * struct iommu_page_response - Generic page response information > > + * @argsz: User filled size of this data > > * @version: API version of this structure > > * @flags: encodes whether the corresponding fields are valid > > * (IOMMU_FAULT_PAGE_RESPONSE_* values) > > @@ -143,6 +144,7 @@ enum iommu_page_response_code { > > * @code: response code from &enum iommu_page_response_code > > */ > > struct iommu_page_response { > > + __u32 argsz; > > #define IOMMU_PAGE_RESP_VERSION_1 1 > Don't you need to incr the version for all the modified structs? not literal "flags" but @cache and @granularity are flags in reality. I think that is OK. I also updated document to say "flags or equivalent". > > __u32 version; > > #define IOMMU_PAGE_RESP_PASID_VALID (1 << 0) > > @@ -218,6 +220,7 @@ struct iommu_inv_pasid_info { > > /** > > * struct iommu_cache_invalidate_info - First level/stage > > invalidation > > * information > > + * @argsz: User filled size of this data > > * @version: API version of this structure > > * @cache: bitfield that allows to select which caches to > > invalidate > > * @granularity: defines the lowest granularity used for the > > invalidation: @@ -246,6 +249,7 @@ struct iommu_inv_pasid_info { > > * must support the used granularity. > > */ > > struct iommu_cache_invalidate_info { > > + __u32 argsz; > > #define IOMMU_CACHE_INVALIDATE_INFO_VERSION_1 1 > > __u32 version; > so there is no "flags" field in this struct. Is it OK? > > /* IOMMU paging structure cache */ > > @@ -255,7 +259,7 @@ struct iommu_cache_invalidate_info { > > #define IOMMU_CACHE_INV_TYPE_NR (3) > > __u8 cache; > > __u8 granularity; > > - __u8 padding[2]; > > + __u8 padding[6]; > > union { > > struct iommu_inv_pasid_info pasid_info; > > struct iommu_inv_addr_info addr_info; > > @@ -292,6 +296,7 @@ struct iommu_gpasid_bind_data_vtd { > > > > /** > > * struct iommu_gpasid_bind_data - Information about device and > > guest PASID binding > > + * @argsz: User filled size of this data > > * @version: Version of this data structure > > * @format: PASID table entry format > > * @flags: Additional information on guest bind request > > @@ -309,17 +314,18 @@ struct iommu_gpasid_bind_data_vtd { > > * PASID to host PASID based on this bind data. > > */ > > struct iommu_gpasid_bind_data { > > + __u32 argsz; > > #define IOMMU_GPASID_BIND_VERSION_1 1 > > __u32 version; > > #define IOMMU_PASID_FORMAT_INTEL_VTD 1 > > __u32 format; > > + __u32 addr_width; > > #define IOMMU_SVA_GPASID_VAL (1 << 0) /* guest PASID valid > > */ __u64 flags; > > __u64 gpgd; > > __u64 hpasid; > > __u64 gpasid; > > - __u32 addr_width; > > - __u8 padding[12]; > > + __u8 padding[8]; > > /* Vendor specific data */ > > union { > > struct iommu_gpasid_bind_data_vtd vtd; > > > Thanks > > Eric > [Jacob Pan]