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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 60232C43331 for ; Thu, 21 Jan 2021 02:35:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DED82388E for ; Thu, 21 Jan 2021 02:35:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436785AbhAUC0M (ORCPT ); Wed, 20 Jan 2021 21:26:12 -0500 Received: from mga07.intel.com ([134.134.136.100]:31113 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389436AbhAUB6K (ORCPT ); Wed, 20 Jan 2021 20:58:10 -0500 IronPort-SDR: Eel21chMWO+df4GH/8jz9vn70NHL5002gHYOOAy+sByKq3t6K+X5s4wFFk3b+48TRfXN5at0fu R8s8CcsC49gw== X-IronPort-AV: E=McAfee;i="6000,8403,9870"; a="243275406" X-IronPort-AV: E=Sophos;i="5.79,362,1602572400"; d="scan'208";a="243275406" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jan 2021 17:53:39 -0800 IronPort-SDR: QNr0O4qpQMTHS7ga7fh2HdCPLX6cLjIEWA7Dfi+bY5r8+391q/1SYFco6bS6gXkO6Ym3Cn9XNe gYyS8ZtGQc+g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.79,362,1602572400"; d="scan'208";a="391762270" Received: from allen-box.sh.intel.com ([10.239.159.28]) by orsmga007.jf.intel.com with ESMTP; 20 Jan 2021 17:53:37 -0800 From: Lu Baolu To: Joerg Roedel , Will Deacon Cc: Ashok Raj , Jacob Pan , Kevin Tian , Liu Yi L , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 3/3] iommu/vt-d: Use INVALID response code instead of FAILURE Date: Thu, 21 Jan 2021 09:45:05 +0800 Message-Id: <20210121014505.1659166-4-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210121014505.1659166-1-baolu.lu@linux.intel.com> References: <20210121014505.1659166-1-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 IOMMU response RESPONSE_FAILURE for a page request in below cases: - When it gets a Page_Request with no PASID; - When it gets a Page_Request with PASID that is not in use for this device. This is allowed by the spec, but IOMMU driver doesn't support such cases today. When the device receives RESPONSE_FAILURE, it sends the device state machine to HALT state. Now if we try to unload the driver, it hangs since the device doesn't send any outbound transactions to host when the driver is trying to clear things up. The only possible responses would be for invalidation requests. Let's use RESPONSE_INVALID instead for now, so that the device state machine doesn't enter HALT state. Suggested-by: Ashok Raj Signed-off-by: Lu Baolu --- drivers/iommu/intel/svm.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 77509a0a863e..021f58899c16 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -907,10 +907,8 @@ static irqreturn_t prq_event_thread(int irq, void *d) u64 address; handled = 1; - req = &iommu->prq[head / sizeof(*req)]; - - result = QI_RESP_FAILURE; + result = QI_RESP_INVALID; address = (u64)req->addr << VTD_PAGE_SHIFT; if (!req->pasid_present) { pr_err("%s: Page request without PASID: %08llx %08llx\n", @@ -948,7 +946,6 @@ static irqreturn_t prq_event_thread(int irq, void *d) rcu_read_unlock(); } - result = QI_RESP_INVALID; /* Since we're using init_mm.pgd directly, we should never take * any faults on kernel addresses. */ if (!svm->mm) -- 2.25.1