From patchwork Thu Sep 17 10:09:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ani Sinha X-Patchwork-Id: 273496 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 DAA43C43461 for ; Thu, 17 Sep 2020 10:15:03 +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 744BE2083B for ; Thu, 17 Sep 2020 10:15:03 +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="xXPcjFiH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 744BE2083B 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]:33858 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIqwQ-0005NQ-JQ for qemu-devel@archiver.kernel.org; Thu, 17 Sep 2020 06:15:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60172) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIqs3-0000SV-JE for qemu-devel@nongnu.org; Thu, 17 Sep 2020 06:10:31 -0400 Received: from mail-pg1-x541.google.com ([2607:f8b0:4864:20::541]:42750) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kIqrn-0003PF-7r for qemu-devel@nongnu.org; Thu, 17 Sep 2020 06:10:31 -0400 Received: by mail-pg1-x541.google.com with SMTP id k14so1075139pgi.9 for ; Thu, 17 Sep 2020 03:10:14 -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=xXPcjFiHHrMOFSCzhVgjem/VWJrUXm9kkxrxNx8QkQVxEFApbPbbHhw+Ikt471TXnz S5GuE96AaQHCyo/bg5tHFd7z/CtfeXRUlZAJxDKSdeqt+LgR3/P6iZTxYTD0rq7P+mbL Sv34QsNiDpIsOldKYp2QMud+yriwEXDbU5JUydFgsNzgk5HVvd5WPrhDAs3Wph2y15AY 3x2zqltAYLV1weUQVgU01lODPSOrvAHLIcwx8xaQfUetzAuyoAsdA+bv2NZeZx+tso2N pWmq/cgVaKulSi2fpi5LYJ39MekWbYZTNyPQfd4iO4prnzCvry7hKd5R8XVhrAvLTzqV YYPw== 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=r6EornM4JtuW5ZsC5ZiD1YgsEi9zHGgt4lJ0dk6mNltvOJatlRUIrx+JYI6DAQPxO3 mHNxrFAT9Nbod0oy5oCrLKETvpMRfv72Sv72a3kjNO1n8tMSHFHIs4KFiQkwXUCB6498 N4PnIwdrMfUyofiu0IidcgKuNE8/sGwM39jKFVQHl9/wkHJ1eEyKkss7AdDfWeTa3Yz+ 5UoO7Jywtpte6uvMeOybTvVKfbSchf2U+5i3XmJiWZRWFA3bEbby8IEBMGdMapSDYl4P NwyfPVPIPuJdzRwF9cM4C5/v0polMAAJPW6xAH+QCdfvO+rqN+DAMxu+OwoQsmzLLHRl DUDA== X-Gm-Message-State: AOAM531c6Y/NAyb9HI7uwn/8agQTphP4mXXD1aQ7Y+vVqy7ckM7wff8v 1J1enGT0VfbI4E25heQE1D4Y1ZRkCOi6IJQj X-Google-Smtp-Source: ABdhPJwYDY64AmvKvgDfTpVXMTJBPkdGvHBBFBfLdp788+IjXzf73Owu+pYUbREGSvTIZvRRwK8RDg== X-Received: by 2002:a62:2581:0:b029:13f:ba38:b113 with SMTP id l123-20020a6225810000b029013fba38b113mr24089078pfl.15.1600337413694; Thu, 17 Sep 2020 03:10:13 -0700 (PDT) Received: from localhost.localdomain ([115.96.122.113]) by smtp.googlemail.com with ESMTPSA id d20sm5241559pjv.39.2020.09.17.03.10.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2020 03:10:12 -0700 (PDT) From: Ani Sinha To: qemu-devel@nongnu.org Subject: [PATCH v7 04/12] Fix a gap where acpi_pcihp_find_hotplug_bus() returns a non-hotpluggable bus Date: Thu, 17 Sep 2020 15:39:39 +0530 Message-Id: <20200917100947.21106-5-ani@anisinha.ca> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200917100947.21106-1-ani@anisinha.ca> References: <20200917100947.21106-1-ani@anisinha.ca> Received-SPF: none client-ip=2607:f8b0:4864:20::541; envelope-from=ani@anisinha.ca; helo=mail-pg1-x541.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; }