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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 5B0C6C31E5B for ; Tue, 18 Jun 2019 15:16:02 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 1E40B213F2 for ; Tue, 18 Jun 2019 15:16:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E40B213F2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id BEC2FE56; Tue, 18 Jun 2019 15:16:01 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 69D92E57 for ; Tue, 18 Jun 2019 15:16:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D3DAB831 for ; Tue, 18 Jun 2019 15:15:59 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id CA3D04D4; Tue, 18 Jun 2019 17:15:56 +0200 (CEST) Date: Tue, 18 Jun 2019 17:15:55 +0200 From: Joerg Roedel To: Jean-Philippe Brucker Subject: Re: [PATCH] iommu: Add padding to struct iommu_fault Message-ID: <20190618151555.GA21128@8bytes.org> References: <20190612131143.GF21613@8bytes.org> <20190612175938.16428-1-jean-philippe.brucker@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190612175938.16428-1-jean-philippe.brucker@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: iommu@lists.linux-foundation.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 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 Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Wed, Jun 12, 2019 at 06:59:38PM +0100, Jean-Philippe Brucker wrote: > Ease future extensions of struct iommu_fault_page_request and struct > iommu_fault_unrecoverable by adding a few bytes of padding. That way, a > new field can be added to either of these structures by simply introducing > a new flag. To extend it after the size limit is reached, a new fault > reporting structure will have to be negotiated with userspace. > > With 56 bytes of padding, the total size of iommu_fault is 64 bytes and > fits in a cache line on a lot of contemporary machines, while providing 16 > and 24 bytes of extension to structures iommu_fault_page_request and > iommu_fault_unrecoverable respectively. > > Signed-off-by: Jean-Philippe Brucker > --- > include/uapi/linux/iommu.h | 2 ++ > 1 file changed, 2 insertions(+) Applied, thanks. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu