From nobody Tue Feb 10 06:07:20 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1600237157; cv=none; d=zohomail.com; s=zohoarc; b=ejO4jxKLDqzilvQ8hCer7bA1pAk7DGulVhcuFXJ2QcmXER9rQRQNByDybz96IZqqFGHUUx5/bkcZ/9bArqwaI//kj6a/uDU6bCwYHFprhF6H5JRtByGmRU2ne4Ft5ms2n9CiXddYu7/UrIUJRCNxyMTrlvnQzf59xaUeSlEsVkc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1600237157; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=tX9XLbRzvavvjyMGPc0edB0FeNbRKcsKHFO3wqmL2TY=; b=YdQq0ysXlLT26boHfCQ4wIgsLmGjIs31F5H50sLp6z9FGShI3AaeSQ1j6doW9Z7seP05TysQsi70Adr2+pVVB4qAVjBc/cte0p9b28gLOJM4b6VZXgmSwa3Dso0jVxo3DUUBzX8+Vl8RXDiBUgaMip/3q9kW12UV+bgWGR70cAY= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1600237157084216.21300520910745; Tue, 15 Sep 2020 23:19:17 -0700 (PDT) Received: from localhost ([::1]:53358 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIQmh-0007Na-WB for importer@patchew.org; Wed, 16 Sep 2020 02:19:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59436) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIQhp-0001hW-Fi for qemu-devel@nongnu.org; Wed, 16 Sep 2020 02:14:13 -0400 Received: from mail-pl1-x643.google.com ([2607:f8b0:4864:20::643]:38372) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kIQhn-0005lC-FI for qemu-devel@nongnu.org; Wed, 16 Sep 2020 02:14:13 -0400 Received: by mail-pl1-x643.google.com with SMTP id c3so2624572plz.5 for ; Tue, 15 Sep 2020 23:14:11 -0700 (PDT) Received: from localhost.localdomain ([203.163.234.244]) by smtp.googlemail.com with ESMTPSA id c20sm583164pfc.209.2020.09.15.23.14.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Sep 2020 23:14:07 -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=tX9XLbRzvavvjyMGPc0edB0FeNbRKcsKHFO3wqmL2TY=; b=CtAL8nJLWNFsdH7iXEqobHGm3zrCOJZYbETTxmud7Rnuf/1hcBvSnjWiv9EL8V72pz mFDduJd/FDvru8WvMnSdm9dLMLjSouH6mbG/4EKjc9o4nta56Xh9pFgMizWpgXIiTrwO UawBrCxo3hgpVT9pc87WBjZ0HKr4eRfPDp5GEUZvo/BacJxgc5JmItSLXs6K/ugw4jHk M8QE5O2/ugT7oQCqjsCoues4c++gBfWuckSWF+S2SErxOCbjUKLfpEOpgmMWUCkNZY0W tUKFK1v/a3eZA5W1VKXLwihSvNM5RD0tIWtY5AixlilHPPw79qJecRQtIsfhoghcVbUf 1Png== 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=tX9XLbRzvavvjyMGPc0edB0FeNbRKcsKHFO3wqmL2TY=; b=a0/dKNFJ4GMw82F4xfoahyvoM5z0aLmuy6MezIEgoEIv+bIm/XsSUAV0Bw5IPzS3kI /8ibfSD6C6nbmhPtA5o26oMDhZTBau8rAS0XcBt7aje459/kzX995xiPu3BOY8SsJMpm 3p507iURloyYDSZW9YH8WsbteT8wXOew2m6NG3QIuIMEYSoHgw/phPOa8+TEg+ixm2CV 3qeqGkJxZyck/Bmdu50lOXY0hIju67r7r9L2ysWca0cDJQ0YXFSPD9tnGVvkiHx5nmgC cwBC/1d2fDJyBRTqhZSP1PuPSh2BV81vNSCMRjlWIeBTIQf8diwuB4JAZ+4uHqwa/NL5 5NUw== X-Gm-Message-State: AOAM531xFuxZQdVh0ECzXrE0Z5w9nduVxVaH6Qu8lr8ggeRxzQHk7AOV gu97F7jqAYtlAbyQ4ZemJh7RYvZfAkTQSOfp X-Google-Smtp-Source: ABdhPJziqO7SF8PYcMidjTSWzmqJ2Byf0cFS5hDjHliajpEiCSIpuL4KXrHtJswzhGcf9ytZecwQeA== X-Received: by 2002:a17:902:8c8c:b029:d1:cc21:9056 with SMTP id t12-20020a1709028c8cb02900d1cc219056mr11302303plo.22.1600236848628; Tue, 15 Sep 2020 23:14:08 -0700 (PDT) From: Ani Sinha To: qemu-devel@nongnu.org Subject: [PATCH v4 04/11] Fix a gap where acpi_pcihp_find_hotplug_bus() returns a non-hotpluggable bus Date: Wed, 16 Sep 2020 11:43:28 +0530 Message-Id: <20200916061335.14045-5-ani@anisinha.ca> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200916061335.14045-1-ani@anisinha.ca> References: <20200916061335.14045-1-ani@anisinha.ca> Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: none client-ip=2607:f8b0:4864:20::643; envelope-from=ani@anisinha.ca; helo=mail-pl1-x643.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: Eduardo Habkost , "Michael S. Tsirkin" , jusual@redhat.com, =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Aleksandar Markovic , Paolo Bonzini , Ani Sinha , Igor Mammedov , Aurelien Jarno , Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 t= he 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 atta= ched to the root bus to get hot-unplugged if the user issues the following set of c= ommmands: 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 whi= ch 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(+) change log: v1: initial patch v4: commit log updated as per suggestion. 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(AcpiPciHpSt= ate *s, int bsel) if (!bsel && !find.bus) { find.bus =3D 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 =3D NULL; + } return find.bus; } =20 --=20 2.17.1