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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0657C433EF for ; Sat, 16 Apr 2022 12:33:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231978AbiDPMgP (ORCPT ); Sat, 16 Apr 2022 08:36:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230055AbiDPMgH (ORCPT ); Sat, 16 Apr 2022 08:36:07 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A27FFE427 for ; Sat, 16 Apr 2022 05:33:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1650112415; x=1681648415; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=s/nEvl/+FxcEwkLWfzrwaMLflIe37RdxIWhxas3awd4=; b=gMgABO3sWFlcsHehJ2wVh301+E2HKhX5Q9PDOKPOVQwS6x9YN4Omc5JU DTjvX/gf8UjUMW5mM7w93Z/SuIj7uy3QQJBmX520m0ERyuEO3Wz03fbLy eXlVzdbDJbplwgyCFmE1ZBTixf23hitqtkmefCs3DrDfUosq2sTCKJvsz zKPe6rLzuzgSAq8GlBv/mol2D4hA2Yx7XRH51309sv+RsvneV0WUdOvmF RSqWiMkQAYl321tCkaqGu3QNihzY7q/k36sQTt/YnlnBBPPDaEkGq2+FE etM0qF3VM/iO6H99Adcr2JAcuEyOuUj199QdWj60v5ob69XB/zfGmyyHI w==; X-IronPort-AV: E=McAfee;i="6400,9594,10318"; a="243221102" X-IronPort-AV: E=Sophos;i="5.90,264,1643702400"; d="scan'208";a="243221102" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2022 05:33:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,264,1643702400"; d="scan'208";a="701332474" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga001.fm.intel.com with ESMTP; 16 Apr 2022 05:33:33 -0700 From: Lu Baolu To: Jacob jun Pan , Kevin Tian , Ashok Raj , Liu Yi L Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Lu Baolu , Jacob Pan Subject: [PATCH 2/3] iommu/vt-d: Drop stop marker messages Date: Sat, 16 Apr 2022 20:30:48 +0800 Message-Id: <20220416123049.879969-3-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220416123049.879969-1-baolu.lu@linux.intel.com> References: <20220416123049.879969-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The VT-d driver explicitly drains the pending page requests when a CPU page table (represented by a mm struct) is unbound from a PASID according to the procedures defined in the VT-d spec. Hence, there's no need to report the stop-marker message in prq_event_thread(). The stop marker messages do not need a response. This drops stop marker messages silently if any of them is found in the page request queue. Signed-off-by: Lu Baolu Reviewed-by: Jacob Pan --- drivers/iommu/intel/svm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index d88af37c20ef..d1c42dfae6ca 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -758,6 +758,10 @@ static irqreturn_t prq_event_thread(int irq, void *d) goto bad_req; } + /* Drop Stop Marker message. No need for a response. */ + if (unlikely(req->lpig && !req->rd_req && !req->wr_req)) + goto prq_advance; + if (!svm || svm->pasid != req->pasid) { /* * It can't go away, because the driver is not permitted -- 2.25.1