From patchwork Fri Sep 11 18:07:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ani Sinha X-Patchwork-Id: 273936 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=-12.5 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 798EAC43461 for ; Fri, 11 Sep 2020 18:09:42 +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 C7E44221F0 for ; Fri, 11 Sep 2020 18:09:40 +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="u3W/o8P1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C7E44221F0 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]:41272 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kGnUR-0004I1-My for qemu-devel@archiver.kernel.org; Fri, 11 Sep 2020 14:09:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53954) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGnTO-0002dn-46 for qemu-devel@nongnu.org; Fri, 11 Sep 2020 14:08:34 -0400 Received: from mail-pg1-x542.google.com ([2607:f8b0:4864:20::542]:35368) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kGnTM-0005xW-Ab for qemu-devel@nongnu.org; Fri, 11 Sep 2020 14:08:33 -0400 Received: by mail-pg1-x542.google.com with SMTP id g29so7218732pgl.2 for ; Fri, 11 Sep 2020 11:08:31 -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=Gel2ySMpTt4f7XUoVi2e2wkLqL2QzwXiN3Z4/PyZJos=; b=u3W/o8P1eTKmxjWMX2yHNNkkKCgTsIAPquXKWN40MOr4kJXyETU1AvIGx6yL1tTQIo 7PQHVM4DSV+yD4YnT3FtJFD8oi0aVTtT1HqgEOTDbYk7wIQcnYPpum6jP49j+6prR0p7 58qBGlkoanNqYPxMPyWRfNotgOePELAryozSTW3DxHT+XZyBYcgS64JUOqoRvfJPlXJ0 V4qdLZOPj7+GkoZsLr8EWd/wXjas0sClF0CP4TPKQwbvAA0M0tgWwk3BHNn6GPvXM7C5 ZkGRYl02l1liPjJLFTZp1ZqR0zZWQrmb2B3iU8hnOs2gEGqXhUoz3EkKZkr+w/P4TgHG Gp/w== 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=Gel2ySMpTt4f7XUoVi2e2wkLqL2QzwXiN3Z4/PyZJos=; b=bFIKmuSyVeitNEfXV68pRp5AY2EgZ68qyovMkWty6PYdCImuBG673TFDQVeg6uai9N 5WTL/hp4FlWrjhfbt3s2t9B2eUTdIRfA7Z33VjxtHC/ePGuPLoHtJb19R/jK5buYa+fX wCxzq7wUkKCUOM9GEQP2N+DusCuuZ1lf/YtrlKfb3hSeXIyv/27SeVcidMkW2WO6DGzN +Ritx7dD6OAyZrjQyTEcnPvU/S3xbzGu+nZ2/mCcXbaxOeXSARBQNEaF0T2QWp5Rd84p u6noqk6L5w7JJoGzHkC4K/PBpk67e5ltmKkiLrlKCIS7153Ydi2ucqPS01vGqxrfkWpu sR5g== X-Gm-Message-State: AOAM531AH6EaG8bSk+1MSHAvBmMhQ8tVQ0/MXYMVEsphjvXFY96o1Qhm /Dqp7dnEiFYo4wab1sx6KXswpID9a3EmEw== X-Google-Smtp-Source: ABdhPJzqaDNA8P/A6MD5VC5ghPPF+/mEPI40V/fEGPDUFg82QlJsx6XF/bjdefD9CRdsXR8NkIbt+Q== X-Received: by 2002:a17:902:b10a:: with SMTP id q10mr3247096plr.156.1599847710585; Fri, 11 Sep 2020 11:08:30 -0700 (PDT) Received: from localhost.localdomain ([115.96.135.201]) by smtp.googlemail.com with ESMTPSA id n9sm2929135pfu.163.2020.09.11.11.08.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Sep 2020 11:08:29 -0700 (PDT) From: Ani Sinha To: qemu-devel@nongnu.org Subject: [PATCH 4/9] Fix a gap where acpi_pcihp_find_hotplug_bus() returns a non-hotpluggable bus Date: Fri, 11 Sep 2020 23:37:50 +0530 Message-Id: <20200911180755.28409-4-ani@anisinha.ca> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200911180755.28409-1-ani@anisinha.ca> References: <20200911180755.28409-1-ani@anisinha.ca> Received-SPF: none client-ip=2607:f8b0:4864:20::542; envelope-from=ani@anisinha.ca; helo=mail-pg1-x542.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: Ani Sinha , Igor Mammedov , jusual@redhat.com, "Michael S. Tsirkin" 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. This patch is based off of tag v5.10 Signed-off-by: Ani Sinha --- 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; }