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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 7282EC5CFC0 for ; Mon, 18 Jun 2018 08:22:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38E8A20864 for ; Mon, 18 Jun 2018 08:22:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38E8A20864 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965592AbeFRIWw (ORCPT ); Mon, 18 Jun 2018 04:22:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55640 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935849AbeFRIWt (ORCPT ); Mon, 18 Jun 2018 04:22:49 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 6063BC7F; Mon, 18 Jun 2018 08:22:48 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jagannathan Raman , Joerg Roedel , Sasha Levin Subject: [PATCH 4.16 163/279] iommu/vt-d: Fix usage of force parameter in intel_ir_reconfigure_irte() Date: Mon, 18 Jun 2018 10:12:28 +0200 Message-Id: <20180618080615.569482551@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180618080608.851973560@linuxfoundation.org> References: <20180618080608.851973560@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jagannathan Raman [ Upstream commit aa7528fe3576d11f4a10237178a723a1f080a547 ] It was noticed that the IRTE configured for guest OS kernel was over-written while the guest was running. As a result, vt-d Posted Interrupts configured for the guest are not being delivered directly, and instead bounces off the host. Every interrupt delivery takes a VM Exit. It was noticed that the following stack is doing the over-write: [ 147.463177] modify_irte+0x171/0x1f0 [ 147.463405] intel_ir_set_affinity+0x5c/0x80 [ 147.463641] msi_domain_set_affinity+0x32/0x90 [ 147.463881] irq_do_set_affinity+0x37/0xd0 [ 147.464125] irq_set_affinity_locked+0x9d/0xb0 [ 147.464374] __irq_set_affinity+0x42/0x70 [ 147.464627] write_irq_affinity.isra.5+0xe1/0x110 [ 147.464895] proc_reg_write+0x38/0x70 [ 147.465150] __vfs_write+0x36/0x180 [ 147.465408] ? handle_mm_fault+0xdf/0x200 [ 147.465671] ? _cond_resched+0x15/0x30 [ 147.465936] vfs_write+0xad/0x1a0 [ 147.466204] SyS_write+0x52/0xc0 [ 147.466472] do_syscall_64+0x74/0x1a0 [ 147.466744] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 reversing the sense of force check in intel_ir_reconfigure_irte() restores proper posted interrupt functionality Signed-off-by: Jagannathan Raman Fixes: d491bdff888e ('iommu/vt-d: Reevaluate vector configuration on activate()') Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/intel_irq_remapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -1136,7 +1136,7 @@ static void intel_ir_reconfigure_irte(st irte->dest_id = IRTE_DEST(cfg->dest_apicid); /* Update the hardware only if the interrupt is in remapped mode. */ - if (!force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) + if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) modify_irte(&ir_data->irq_2_iommu, irte); }