From patchwork Thu Sep 17 15:00:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ani Sinha X-Patchwork-Id: 273465 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=-12.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,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 ABAA5C433E2 for ; Thu, 17 Sep 2020 15:09:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 140A220708 for ; Thu, 17 Sep 2020 15:09:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=anisinha-ca.20150623.gappssmtp.com header.i=@anisinha-ca.20150623.gappssmtp.com header.b="P3dFdiby" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 140A220708 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=anisinha.ca Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58640 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIvXD-00040j-1t for qemu-devel@archiver.kernel.org; Thu, 17 Sep 2020 11:09:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54378) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIvPS-0001cI-Fp for qemu-devel@nongnu.org; Thu, 17 Sep 2020 11:01:18 -0400 Received: from mail-pl1-x641.google.com ([2607:f8b0:4864:20::641]:44335) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kIvPP-0000zQ-EL for qemu-devel@nongnu.org; Thu, 17 Sep 2020 11:01:17 -0400 Received: by mail-pl1-x641.google.com with SMTP id j7so1258260plk.11 for ; Thu, 17 Sep 2020 08:01:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=anisinha-ca.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=WIzwySGHusyyqcxBP6wP/5K/w/rrBhlYTKtBQXK9Uy8=; b=P3dFdibyVXyQ4ZKwOW+e6o6AkASN67WG+tqCQTD7NBpVWSlu2xB3Jbu1nELQXme+ts QzM60iOmlbhD2Qc6qygJ95Zb+xHeEKe1JPHAWpT6pHTqi1lQQ7L3nh+2hNUcpGAfbIhZ khdKsoW6T9AqNTLRLkfL708GEjIjoaugw/KV/pK74ex0R/c4Tsn9CGmZ8JE1ZfUN9kbr ZARcciGVNR5ktaGgR0xNTeGtw7zEXDJrk1/xCn0EeyF+wJURveDjSa6aXUpKszDADytl uQD00y/ZesIBCwhAMyqmvr5wQubdBtXJc13+jEmKKeg8z7q2ElVT5Q7fOssL2Ir4kCXx y2SA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=WIzwySGHusyyqcxBP6wP/5K/w/rrBhlYTKtBQXK9Uy8=; b=jXpGtg2WEmwrogT7YNPkTh0PofPXDgtoTFGrg2uYnwazRqDWmpgjh307SpdWL85iiU FKihPrNAH4j8o6XLas2LyP8OgxzfbIqLT8nWMOTZ0IpfBeGxc0HazZi66uH1g+yMYxdr 2DiMQS2yBCCJMEtP7LWFZprtgdFNfUqMmhGkRfADv5CQ03tgUHs5OCE49Q0K6OgXygTX IVBnqXU8eoiQvzWPmB+0CXP8LcNS5u3xKZ2eJ7OBwHQFaP9mvajIHE6JQlXO+mRJkWqP ++7wDupYpypD2yObk5J0zU0DhsnKaj5kwlqkvO1XhpMxhJecuV+rH/LzsgotFbLsO+Dx cjRg== X-Gm-Message-State: AOAM532AsnPr7G0jaBfQfuRbCrLR61NQa/lv0XSjsGhRIIlE1CrSRoIX iZruwHU97Xahvf1Tcms3/uG0zXXkXfwsrXZN X-Google-Smtp-Source: ABdhPJx/Y5yMQiAkKXklavjR5qvGYdlgWxyMnN9qtT1mOQESJaYnZZrZpjyKq7hqVeVnKMzIDQISKg== X-Received: by 2002:a17:902:bb82:b029:d1:e5e7:bde6 with SMTP id m2-20020a170902bb82b02900d1e5e7bde6mr11658102pls.70.1600354870841; Thu, 17 Sep 2020 08:01:10 -0700 (PDT) Received: from localhost.localdomain ([115.96.151.231]) by smtp.googlemail.com with ESMTPSA id e10sm17674374pgb.45.2020.09.17.08.01.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2020 08:01:10 -0700 (PDT) From: Ani Sinha To: qemu-devel@nongnu.org Subject: [PATCH v8 04/12] Fix a gap where acpi_pcihp_find_hotplug_bus() returns a non-hotpluggable bus Date: Thu, 17 Sep 2020 20:30:36 +0530 Message-Id: <20200917150044.23159-5-ani@anisinha.ca> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200917150044.23159-1-ani@anisinha.ca> References: <20200917150044.23159-1-ani@anisinha.ca> Received-SPF: none client-ip=2607:f8b0:4864:20::641; envelope-from=ani@anisinha.ca; helo=mail-pl1-x641.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Thomas Huth , "Michael S. Tsirkin" , jusual@redhat.com, Paolo Bonzini , Ani Sinha , Igor Mammedov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" When ACPI hotplug for the root bus is disabled, the bsel property for that bus is not set. Please see the following commit: 3d7e78aa7777f ("Introduce a new flag for i440fx to disable PCI hotplug on the root bus"). As a result, when acpi_pcihp_find_hotplug_bus() is called with bsel set to 0, it may return the root bus. This can cause devices attached to the root bus to get hot-unplugged if the user issues the following set of commmands: outl 0xae10 0 outl 0xae08 your_slot Thanks to Julia for pointing this out here: https://www.mail-archive.com/qemu-devel@nongnu.org/msg734548.html In this patch, we fix the issue in this function by checking if the bus which is returned by the function is actually hotpluggable. If not, we simply return NULL. This avoids the scenario where we were returning a non-hotpluggable bus. Signed-off-by: Ani Sinha Reviewed-by: Igor Mammedov --- hw/acpi/pcihp.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c index 39b1f74442..32ae8b2c0a 100644 --- a/hw/acpi/pcihp.c +++ b/hw/acpi/pcihp.c @@ -147,6 +147,21 @@ static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel) if (!bsel && !find.bus) { find.bus = s->root; } + + /* + * Check if find.bus is actually hotpluggable. If bsel is set to + * NULL for example on the root bus in order to make it + * non-hotpluggable, find.bus will match the root bus when bsel + * is 0. See acpi_pcihp_test_hotplug_bus() above. Since the + * bus is not hotpluggable however, we should not select the bus. + * Instead, we should set find.bus to NULL in that case. In the check + * below, we generalize this case for all buses, not just the root bus. + * The callers of this function check for a null return value and + * handle them appropriately. + */ + if (find.bus && !qbus_is_hotpluggable(BUS(find.bus))) { + find.bus = NULL; + } return find.bus; }