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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 2A4FFC433E2 for ; Fri, 4 Sep 2020 09:39:55 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 ECF63205CB for ; Fri, 4 Sep 2020 09:39:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECF63205CB 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 localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id C4B4187514; Fri, 4 Sep 2020 09:39:54 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 0TojJ-xG+bUH; Fri, 4 Sep 2020 09:39:52 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id E988087512; Fri, 4 Sep 2020 09:39:52 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id D1BA8C0052; Fri, 4 Sep 2020 09:39:52 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id ADEE9C0051 for ; Fri, 4 Sep 2020 09:39:51 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id A1DF286D99 for ; Fri, 4 Sep 2020 09:39:51 +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 Q7Nu0lNWT9Ep for ; Fri, 4 Sep 2020 09:39:48 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by whitealder.osuosl.org (Postfix) with ESMTPS id 9D05C86D70 for ; Fri, 4 Sep 2020 09:39:48 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id 2631D9CE; Fri, 4 Sep 2020 11:39:47 +0200 (CEST) Date: Fri, 4 Sep 2020 11:39:45 +0200 From: Joerg Roedel To: Lu Baolu Subject: Re: [PATCH v3 1/1] iommu/vt-d: Serialize IOMMU GCMD register modifications Message-ID: <20200904093945.GO6714@8bytes.org> References: <20200828000615.8281-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200828000615.8281-1-baolu.lu@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: Kevin Tian , Ashok Raj , linux-kernel@vger.kernel.org, Andy Lutomirski , iommu@lists.linux-foundation.org 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 Fri, Aug 28, 2020 at 08:06:15AM +0800, Lu Baolu wrote: > The VT-d spec requires (10.4.4 Global Command Register, GCMD_REG General > Description) that: > > If multiple control fields in this register need to be modified, software > must serialize the modifications through multiple writes to this register. > > However, in irq_remapping.c, modifications of IRE and CFI are done in one > write. We need to do two separate writes with STS checking after each. It > also checks the status register before writing command register to avoid > unnecessary register write. > > Fixes: af8d102f999a4 ("x86/intel/irq_remapping: Clean up x2apic opt-out security warning mess") > Cc: Andy Lutomirski > Cc: Jacob Pan > Cc: Kevin Tian > Cc: Ashok Raj > Signed-off-by: Lu Baolu > --- > drivers/iommu/intel/irq_remapping.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) Applied for v5.9, thanks. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 B1448C43461 for ; Fri, 4 Sep 2020 09:39:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8EE3720791 for ; Fri, 4 Sep 2020 09:39:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729707AbgIDJjt (ORCPT ); Fri, 4 Sep 2020 05:39:49 -0400 Received: from 8bytes.org ([81.169.241.247]:41010 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725812AbgIDJjt (ORCPT ); Fri, 4 Sep 2020 05:39:49 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id 2631D9CE; Fri, 4 Sep 2020 11:39:47 +0200 (CEST) Date: Fri, 4 Sep 2020 11:39:45 +0200 From: Joerg Roedel To: Lu Baolu Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Jacob Pan , Kevin Tian , Ashok Raj Subject: Re: [PATCH v3 1/1] iommu/vt-d: Serialize IOMMU GCMD register modifications Message-ID: <20200904093945.GO6714@8bytes.org> References: <20200828000615.8281-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200828000615.8281-1-baolu.lu@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 28, 2020 at 08:06:15AM +0800, Lu Baolu wrote: > The VT-d spec requires (10.4.4 Global Command Register, GCMD_REG General > Description) that: > > If multiple control fields in this register need to be modified, software > must serialize the modifications through multiple writes to this register. > > However, in irq_remapping.c, modifications of IRE and CFI are done in one > write. We need to do two separate writes with STS checking after each. It > also checks the status register before writing command register to avoid > unnecessary register write. > > Fixes: af8d102f999a4 ("x86/intel/irq_remapping: Clean up x2apic opt-out security warning mess") > Cc: Andy Lutomirski > Cc: Jacob Pan > Cc: Kevin Tian > Cc: Ashok Raj > Signed-off-by: Lu Baolu > --- > drivers/iommu/intel/irq_remapping.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) Applied for v5.9, thanks.