From patchwork Fri Apr 19 00:30:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wei Yang X-Patchwork-Id: 10908591 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AACE21515 for ; Fri, 19 Apr 2019 00:49:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 93B4A286F2 for ; Fri, 19 Apr 2019 00:49:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 85629287A6; Fri, 19 Apr 2019 00:49:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2755A286F2 for ; Fri, 19 Apr 2019 00:49:46 +0000 (UTC) Received: from localhost ([127.0.0.1]:49307 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hHHir-0003tq-3S for patchwork-qemu-devel@patchwork.kernel.org; Thu, 18 Apr 2019 20:49:45 -0400 Received: from eggs.gnu.org ([209.51.188.92]:35712) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hHHcA-0007cN-Bc for qemu-devel@nongnu.org; Thu, 18 Apr 2019 20:42:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hHHRB-0005ni-Qf for qemu-devel@nongnu.org; Thu, 18 Apr 2019 20:31:30 -0400 Received: from mga18.intel.com ([134.134.136.126]:3679) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hHHRA-0005kx-EK; Thu, 18 Apr 2019 20:31:28 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Apr 2019 17:31:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,367,1549958400"; d="scan'208";a="163163305" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga004.fm.intel.com with ESMTP; 18 Apr 2019 17:31:24 -0700 From: Wei Yang To: qemu-devel@nongnu.org, qemu-arm@nongnu.org Date: Fri, 19 Apr 2019 08:30:48 +0800 Message-Id: <20190419003053.8260-2-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190419003053.8260-1-richardw.yang@linux.intel.com> References: <20190419003053.8260-1-richardw.yang@linux.intel.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.126 Subject: [Qemu-devel] [PATCH v4 1/6] q35: acpi: do not create dummy MCFG table X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: yang.zhong@intel.com, peter.maydell@linaro.org, mst@redhat.com, shannon.zhaosl@gmail.com, Wei Yang , imammedo@redhat.com, philmd@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Igor Mammedov Dummy table (with signature "QEMU") creation came from original SeaBIOS codebase. And QEMU would have to keep it around if there were Q35 machine that depended on keeping ACPI tables blob constant size. Luckily there were no versioned Q35 machine types before commit: (since 2.3) a1666142db acpi-build: make ROMs RAM blocks resizeable which obsoleted need to keep ACPI tables blob the same size on source/destination. Considering the 1st versioned machine is pc-q35-2.4, the dummy table is not really necessary and it's safe to drop it without breaking cross version migration in both directions unconditionally. Signed-off-by: Igor Mammedov Signed-off-by: Wei Yang Reviewed-by: Philippe Mathieu-Daudé --- hw/i386/acpi-build.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index b17d4a711d..d009176072 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2401,7 +2401,6 @@ static void build_mcfg_q35(GArray *table_data, BIOSLinker *linker, AcpiMcfgInfo *info) { AcpiTableMcfg *mcfg; - const char *sig; int len = sizeof(*mcfg) + 1 * sizeof(mcfg->allocation[0]); mcfg = acpi_data_push(table_data, len); @@ -2411,19 +2410,7 @@ build_mcfg_q35(GArray *table_data, BIOSLinker *linker, AcpiMcfgInfo *info) mcfg->allocation[0].start_bus_number = 0; mcfg->allocation[0].end_bus_number = PCIE_MMCFG_BUS(info->mcfg_size - 1); - /* MCFG is used for ECAM which can be enabled or disabled by guest. - * To avoid table size changes (which create migration issues), - * always create the table even if there are no allocations, - * but set the signature to a reserved value in this case. - * ACPI spec requires OSPMs to ignore such tables. - */ - if (info->mcfg_base == PCIE_BASE_ADDR_UNMAPPED) { - /* Reserved signature: ignored by OSPM */ - sig = "QEMU"; - } else { - sig = "MCFG"; - } - build_header(linker, table_data, (void *)mcfg, sig, len, 1, NULL, NULL); + build_header(linker, table_data, (void *)mcfg, "MCFG", len, 1, NULL, NULL); } /* @@ -2592,6 +2579,9 @@ static bool acpi_get_mcfg(AcpiMcfgInfo *mcfg) } mcfg->mcfg_base = qnum_get_uint(qobject_to(QNum, o)); qobject_unref(o); + if (mcfg->mcfg_base == PCIE_BASE_ADDR_UNMAPPED) { + return false; + } o = object_property_get_qobject(pci_host, PCIE_HOST_MCFG_SIZE, NULL); assert(o);