From patchwork Thu Sep 17 07:47:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ani Sinha X-Patchwork-Id: 305174 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 48826C43461 for ; Thu, 17 Sep 2020 07:52:44 +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 D23C1221EF for ; Thu, 17 Sep 2020 07:52:43 +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="gxO3Vwy3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D23C1221EF 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]:52686 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIoig-000687-UC for qemu-devel@archiver.kernel.org; Thu, 17 Sep 2020 03:52:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50686) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIoeH-000858-TW for qemu-devel@nongnu.org; Thu, 17 Sep 2020 03:48:09 -0400 Received: from mail-pj1-x1044.google.com ([2607:f8b0:4864:20::1044]:55373) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kIoeF-0004oz-P1 for qemu-devel@nongnu.org; Thu, 17 Sep 2020 03:48:09 -0400 Received: by mail-pj1-x1044.google.com with SMTP id q4so828449pjh.5 for ; Thu, 17 Sep 2020 00:48:06 -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=gxO3Vwy3/F2P44bpyPiYBuQfkF33M9CXr3wejPzTTda6Q6/MhtDRKoLjXTHfw1K6qI GzyFRlWrJsZ1mZiSar3lDpB98jinYFTyZxkLRKloqIyfSVA3HJ68rIRwFkpoU3W/jYf0 ctiT96rknVPdV6eMvQXrEvMzez8PaEXR5g135tMfrV0sG81oXB2mSGX+ucNUi7PWD3wj pARFsHglks6tTRm8Y0eqGiph23La/YVez3eSMUs9B6J7yzlj1/dJ9KnI1194gqfmIquB uEOxwgYD4hKOk+eFW6oTuMnuLuAnOuWmj8G5j+7+bPz7tktRCvIGD+Gpvs1wTLfBMxLX ktcg== 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=GuCzbrvW8RMs1yF5SXOiblVOlhNU+gh3KYnIWNJLTP2HI6tEERjJ357pvyNd9xn4kX Z7FxLHIe60xSZXVkdXlvRYpHByBi11V74oRVPqIzJrqcGsGjq1m4Rj9lsj921URPvKpG pjgfoIrLd6DFTQN07yRUmCeXqqs8o9ES0ry3BZ5HrRhiOBnJAaE/iMUZiXDautoyJ4Bf HdVgKphGUPA0JeqHibF5YmU5xT5TmGEQWrYM1/XNMwS+kcYz6X+wpq6RnnIattRMrm/p cbSBlTavYF3aGYQeXMLQkFWOEI6zECh0xOUOqD9rd9SbC75gBOfArYNCztfANn/JDcKQ ga7g== X-Gm-Message-State: AOAM530Ltrn5CW8/ZUszSlI9/ChQLvc1rYwMyOuFUWkp+MIBZfOu64pp 5ngekZpTgADi+o7BJAedQFu4jBZYvqJcOLul X-Google-Smtp-Source: ABdhPJz0727rqNl+WZRjGLmP54xs8X6tRYy9Cb2VVfn11YKBBcvB/DmqTmY2SHKgGw6o2ngAuUgRDg== X-Received: by 2002:a17:90a:f992:: with SMTP id cq18mr7452906pjb.136.1600328885660; Thu, 17 Sep 2020 00:48:05 -0700 (PDT) Received: from localhost.localdomain ([115.96.122.113]) by smtp.googlemail.com with ESMTPSA id y3sm20572516pfb.18.2020.09.17.00.48.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2020 00:48:04 -0700 (PDT) From: Ani Sinha To: qemu-devel@nongnu.org Subject: [PATCH v6 04/12] Fix a gap where acpi_pcihp_find_hotplug_bus() returns a non-hotpluggable bus Date: Thu, 17 Sep 2020 13:17:24 +0530 Message-Id: <20200917074733.13612-5-ani@anisinha.ca> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200917074733.13612-1-ani@anisinha.ca> References: <20200917074733.13612-1-ani@anisinha.ca> Received-SPF: none client-ip=2607:f8b0:4864:20::1044; envelope-from=ani@anisinha.ca; helo=mail-pj1-x1044.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_Mathieu-Daud?= =?utf-8?b?w6k=?= , Aleksandar Markovic , Paolo Bonzini , Ani Sinha , Igor Mammedov , Aurelien Jarno , Richard Henderson 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; }