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=-11.2 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_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 3239EC43464 for ; Fri, 18 Sep 2020 09:45:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC56621D7B for ; Fri, 18 Sep 2020 09:45:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726614AbgIRJo5 (ORCPT ); Fri, 18 Sep 2020 05:44:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbgIRJo4 (ORCPT ); Fri, 18 Sep 2020 05:44:56 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AB1DC06174A for ; Fri, 18 Sep 2020 02:44:55 -0700 (PDT) Received: by theia.8bytes.org (Postfix, from userid 1000) id 00962293; Fri, 18 Sep 2020 11:44:51 +0200 (CEST) Date: Fri, 18 Sep 2020 11:44:50 +0200 From: Joerg Roedel To: Jacob Pan Cc: iommu@lists.linux-foundation.org, LKML , Alex Williamson , Lu Baolu , David Woodhouse , Jonathan Corbet , Jean-Philippe Brucker , Eric Auger , Jacob Pan , Yi Liu , "Tian, Kevin" , Raj Ashok , Wu Hao , Yi Sun Subject: Re: [PATCH v9 3/7] iommu/uapi: Introduce enum type for PASID data format Message-ID: <20200918094450.GP31590@8bytes.org> References: <1599861476-53416-1-git-send-email-jacob.jun.pan@linux.intel.com> <1599861476-53416-4-git-send-email-jacob.jun.pan@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1599861476-53416-4-git-send-email-jacob.jun.pan@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 11, 2020 at 02:57:52PM -0700, Jacob Pan wrote: > There can be multiple vendor-specific PASID data formats used in UAPI > structures. This patch adds enum type with a last entry which makes > range checking much easier. But it also makes it much easier to screw up the numbers (which are ABI) by inserting a new value into the middle. I prefer defines here, or alternativly BUILD_BUG_ON() checks for the numbers. Regards, Joerg > > Suggested-by: Alex Williamson > Reviewed-by: Eric Auger > Signed-off-by: Jacob Pan > --- > include/uapi/linux/iommu.h | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h > index b42acc8fe007..7cc6ee6c41f7 100644 > --- a/include/uapi/linux/iommu.h > +++ b/include/uapi/linux/iommu.h > @@ -298,11 +298,16 @@ struct iommu_gpasid_bind_data_vtd { > IOMMU_SVA_VTD_GPASID_PCD | \ > IOMMU_SVA_VTD_GPASID_PWT) > > +enum iommu_pasid_data_format { > + IOMMU_PASID_FORMAT_INTEL_VTD = 1, > + IOMMU_PASID_FORMAT_LAST, > +}; > + > /** > * 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 > + * @format: PASID table entry format of enum iommu_pasid_data_format type > * @flags: Additional information on guest bind request > * @gpgd: Guest page directory base of the guest mm to bind > * @hpasid: Process address space ID used for the guest mm in host IOMMU > @@ -321,7 +326,6 @@ 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 */ > -- > 2.7.4