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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 7445AECDE4B for ; Thu, 8 Nov 2018 21:56:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3AB5B2089F for ; Thu, 8 Nov 2018 21:56:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="oHCWAC6T" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3AB5B2089F 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 S1728992AbeKIHdj (ORCPT ); Fri, 9 Nov 2018 02:33:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:49428 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728900AbeKIHdi (ORCPT ); Fri, 9 Nov 2018 02:33:38 -0500 Received: from localhost (unknown [208.72.13.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3647621104; Thu, 8 Nov 2018 21:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541714170; bh=VirZwrLd6KwzxlPyBRfgeerhEFpSwo5yxcuPYdN+DAM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oHCWAC6TRbdb1tvvZznRqmrOEYAdrXTU1mK8lNLH4kc6dbQ3aFdn77bZuMNddfUlj xGb3sBy7dbHQkdvodtWOwNUyDvzFxJsEBwLOmv5H2u4I+Mu3IeZeQ7m//xgCzDtpar 3bDbKBLzjWLixJvRYmxrRsLMWTK5FEDSDAtzd0Jg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Williamson , Jiang Liu , Joerg Roedel , Sasha Levin Subject: [PATCH 3.18 092/144] iommu/vt-d: Fix VM domain ID leak Date: Thu, 8 Nov 2018 13:51:03 -0800 Message-Id: <20181108215102.527593662@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181108215054.826084593@linuxfoundation.org> References: <20181108215054.826084593@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 46ebb7af7b93792de65e124e1ab8b89a108a41f2 ] This continues the attempt to fix commit fb170fb4c548 ("iommu/vt-d: Introduce helper functions to make code symmetric for readability"). The previous attempt in commit 71684406905f ("iommu/vt-d: Detach domain *only* from attached iommus") overlooked the fact that dmar_domain.iommu_bmp gets cleared for VM domains when devices are detached: intel_iommu_detach_device domain_remove_one_dev_info domain_detach_iommu The domain is detached from the iommu, but the iommu is still attached to the domain, for whatever reason. Thus when we get to domain_exit(), we can't rely on iommu_bmp for VM domains to find the active iommus, we must check them all. Without that, the corresponding bit in intel_iommu.domain_ids doesn't get cleared and repeated VM domain creation and destruction will run out of domain IDs. Meanwhile we still can't call iommu_detach_domain() on arbitrary non-VM domains or we risk clearing in-use domain IDs, as 71684406905f attempted to address. It's tempting to modify iommu_detach_domain() to test the domain iommu_bmp, but the call ordering from domain_remove_one_dev_info() prevents it being able to work as fb170fb4c548 seems to have intended. Caching of unused VM domains on the iommu object seems to be the root of the problem, but this code is far too fragile for that kind of rework to be proposed for stable, so we simply revert this chunk to its state prior to fb170fb4c548. Fixes: fb170fb4c548 ("iommu/vt-d: Introduce helper functions to make code symmetric for readability") Fixes: 71684406905f ("iommu/vt-d: Detach domain *only* from attached iommus") Signed-off-by: Alex Williamson Cc: Jiang Liu Cc: stable@vger.kernel.org # v3.17+ Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/intel-iommu.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 351da1da814f..2068cb59f7ed 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1759,8 +1759,9 @@ static int domain_init(struct dmar_domain *domain, int guest_width) static void domain_exit(struct dmar_domain *domain) { + struct dmar_drhd_unit *drhd; + struct intel_iommu *iommu; struct page *freelist = NULL; - int i; /* Domain 0 is reserved, so dont process it */ if (!domain) @@ -1780,8 +1781,10 @@ static void domain_exit(struct dmar_domain *domain) /* clear attached or cached domains */ rcu_read_lock(); - for_each_set_bit(i, domain->iommu_bmp, g_num_of_iommus) - iommu_detach_domain(domain, g_iommus[i]); + for_each_active_iommu(iommu, drhd) + if (domain_type_is_vm(domain) || + test_bit(iommu->seq_id, domain->iommu_bmp)) + iommu_detach_domain(domain, iommu); rcu_read_unlock(); dma_free_pagelist(freelist); -- 2.17.1