From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 9925DC2D0CD for ; Thu, 15 May 2025 12:42:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uFXuR-0002Zh-Ha; Thu, 15 May 2025 08:42:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uFXuH-0002Mv-7H; Thu, 15 May 2025 08:41:49 -0400 Received: from sender4-op-o15.zoho.com ([136.143.188.15]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uFXuF-0007dz-3o; Thu, 15 May 2025 08:41:48 -0400 ARC-Seal: i=1; a=rsa-sha256; t=1747312870; cv=none; d=zohomail.com; s=zohoarc; b=lXKazK33GIGXnAh4qcXAAOgVa2y7N8MRhVEroh39T4RhKCVSUd2rft64OWjSX5J4RI81esF+UAJAvCwx9sOa9qA/hW1gHEYCXT7VUEosrPmL0KRKvVxugXyZb6qxOzO9cvASd6ZPqhDdTo/HzGpZ9dxukNMRiVmE14qLqBiom7o= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1747312870; h=Content-Type:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To:Cc; bh=sOoa7OazfG9PBNcg4uZXxjwpzZMA8hhvpy2CeeEbcoo=; b=EKSqX9eM/5nkSS/Y2CczNHWQEgVYNjqvyZygn+WREWKU/TvYep7xgNVOjt/Pi8IcAe8nklqKC6eYnAGfMxcdcaX18lze/67X5ONzTcrC79AFdu+Rc3526eiE+mRvZ2VlRk+6dRwdowPWnumtEwgo4g6y7HupeMp9hBwQb7qquok= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=linux.beauty; spf=pass smtp.mailfrom=me@linux.beauty; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1747312870; s=zmail; d=linux.beauty; i=me@linux.beauty; h=Date:Date:Message-ID:From:From:To:To:Subject:Subject:In-Reply-To:References:MIME-Version:Content-Type:Message-Id:Reply-To:Cc; bh=sOoa7OazfG9PBNcg4uZXxjwpzZMA8hhvpy2CeeEbcoo=; b=FgL8bvG+7c7151dVUic9YBN5jWbU9PafdkDYyxVR4CvohRVGpjBADjTt4MRc4h5O mEnwQv1zxdKX7oyN5riv+fx7PsmShGVRVDGWVoOqRB6Ov/i2prlo8v+zO5rq1ufC0HC pAr01KQR5QamsztbcDjjr2a3OFHGHbxBPGal/lZM= Received: by mx.zohomail.com with SMTPS id 1747312868309660.3907576829178; Thu, 15 May 2025 05:41:08 -0700 (PDT) Date: Thu, 15 May 2025 20:41:03 +0800 Message-ID: <87ldqyrqqo.wl-me@linux.beauty> From: Li Chen To: "Peter Maydell" , "Shannon Zhao" , "Michael S. Tsirkin" , "Igor Mammedov" , "Ani Sinha" , "Eduardo Habkost" , "Marcel Apfelbaum" , =?ISO-8859-1?Q?=22Philippe_Mathieu-Daud=E9?= =?ISO-8859-1?Q?=22?= , "Yanan Wang" , "Zhao Liu" , "Song Gao" , "Jiaxun Yang" , "Sunil V L" , "Palmer Dabbelt" , "Alistair Francis" , "Weiwei Li" , "qemu-arm" , "qemu-devel" , "qemu-riscv" Subject: [PATCH V3 1/4] acpi: Add machine option to disable SPCR table In-Reply-To: <87msberqzi.wl-me@linux.beauty> References: <87msberqzi.wl-me@linux.beauty> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?ISO-8859-4?Q?Goj=F2?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-ZohoMailClient: External Received-SPF: pass client-ip=136.143.188.15; envelope-from=me@linux.beauty; helo=sender4-op-o15.zoho.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-riscv@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-riscv-bounces+qemu-riscv=archiver.kernel.org@nongnu.org Sender: qemu-riscv-bounces+qemu-riscv=archiver.kernel.org@nongnu.org From: Li Chen The ACPI SPCR (Serial Port Console Redirection) table allows firmware to specify a preferred serial console device to the operating system. On ARM64 systems, Linux by default respects this table: even if the kernel command line does not include a hardware serial console (e.g., "console=ttyAMA0"), the kernel still register the serial device referenced by SPCR as a printk console. While this behavior is standard-compliant, it can lead to situations where guest console behavior is influenced by platform firmware rather than user-specified configuration. To make guest console behavior more predictable and under user control, this patch introduces a machine option to explicitly disable SPCR table exposure: -machine spcr=off By default, the option is enabled (spcr=on), preserving existing behavior. When disabled, QEMU will omit the SPCR table from the guest's ACPI namespace, ensuring that only consoles explicitly declared in the kernel command line are registered. Signed-off-by: Li Chen Reviewed-by: Bibo Mao Acked-by: Michael S. Tsirkin Reviewed-by: Gavin Shan --- Changes since V2: Add Reviewed-by from Gavin Shan for the first patch and fix style issue. Changes since V1: add Reviewed-by and Acked-by hw/arm/virt-acpi-build.c | 5 ++++- hw/core/machine.c | 22 ++++++++++++++++++++++ hw/loongarch/virt-acpi-build.c | 4 +++- hw/riscv/virt-acpi-build.c | 5 ++++- include/hw/boards.h | 1 + qemu-options.hx | 5 +++++ 6 files changed, 39 insertions(+), 3 deletions(-) diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c index 3ac8f8e178..f25c3b26ce 100644 --- a/hw/arm/virt-acpi-build.c +++ b/hw/arm/virt-acpi-build.c @@ -940,7 +940,10 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables) } acpi_add_table(table_offsets, tables_blob); - spcr_setup(tables_blob, tables->linker, vms); + + if (ms->enable_spcr) { + spcr_setup(tables_blob, tables->linker, vms); + } acpi_add_table(table_offsets, tables_blob); build_dbg2(tables_blob, tables->linker, vms); diff --git a/hw/core/machine.c b/hw/core/machine.c index ed01798d37..71a935512e 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -593,6 +593,20 @@ static void machine_set_nvdimm(Object *obj, bool value, Error **errp) ms->nvdimms_state->is_enabled = value; } +static bool machine_get_spcr(Object *obj, Error **errp) +{ + MachineState *ms = MACHINE(obj); + + return ms->enable_spcr; +} + +static void machine_set_spcr(Object *obj, bool value, Error **errp) +{ + MachineState *ms = MACHINE(obj); + + ms->enable_spcr = value; +} + static bool machine_get_hmat(Object *obj, Error **errp) { MachineState *ms = MACHINE(obj); @@ -1297,6 +1311,14 @@ static void machine_initfn(Object *obj) "Table (HMAT)"); } + /* SPCR */ + ms->enable_spcr = true; + object_property_add_bool(obj, "spcr", machine_get_spcr, machine_set_spcr); + object_property_set_description(obj, "spcr", + "Set on/off to enable/disable " + "ACPI Serial Port Console Redirection " + "Table (spcr)"); + /* default to mc->default_cpus */ ms->smp.cpus = mc->default_cpus; ms->smp.max_cpus = mc->default_cpus; diff --git a/hw/loongarch/virt-acpi-build.c b/hw/loongarch/virt-acpi-build.c index fced6c445a..0e437bcf25 100644 --- a/hw/loongarch/virt-acpi-build.c +++ b/hw/loongarch/virt-acpi-build.c @@ -557,7 +557,9 @@ static void acpi_build(AcpiBuildTables *tables, MachineState *machine) acpi_add_table(table_offsets, tables_blob); build_srat(tables_blob, tables->linker, machine); acpi_add_table(table_offsets, tables_blob); - spcr_setup(tables_blob, tables->linker, machine); + + if (machine->enable_spcr) + spcr_setup(tables_blob, tables->linker, machine); if (machine->numa_state->num_nodes) { if (machine->numa_state->have_numa_distance) { diff --git a/hw/riscv/virt-acpi-build.c b/hw/riscv/virt-acpi-build.c index 1ad6800508..7f6d221c63 100644 --- a/hw/riscv/virt-acpi-build.c +++ b/hw/riscv/virt-acpi-build.c @@ -680,7 +680,10 @@ static void virt_acpi_build(RISCVVirtState *s, AcpiBuildTables *tables) build_rhct(tables_blob, tables->linker, s); acpi_add_table(table_offsets, tables_blob); - spcr_setup(tables_blob, tables->linker, s); + + if (ms->enable_spcr) { + spcr_setup(tables_blob, tables->linker, s); + } acpi_add_table(table_offsets, tables_blob); { diff --git a/include/hw/boards.h b/include/hw/boards.h index 765dc8dd35..089104d54b 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -444,6 +444,7 @@ struct MachineState { SmpCache smp_cache; struct NVDIMMState *nvdimms_state; struct NumaState *numa_state; + bool enable_spcr; }; /* diff --git a/qemu-options.hx b/qemu-options.hx index dc694a99a3..953680595f 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -38,6 +38,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ " nvdimm=on|off controls NVDIMM support (default=off)\n" " memory-encryption=@var{} memory encryption object to use (default=none)\n" " hmat=on|off controls ACPI HMAT support (default=off)\n" + " spcr=on|off controls ACPI SPCR support (default=on)\n" #ifdef CONFIG_POSIX " aux-ram-share=on|off allocate auxiliary guest RAM as shared (default: off)\n" #endif @@ -105,6 +106,10 @@ SRST Enables or disables ACPI Heterogeneous Memory Attribute Table (HMAT) support. The default is off. + ``spcr=on|off`` + Enables or disables ACPI Serial Port Console Redirection Table + (SPCR) support. The default is on. + ``aux-ram-share=on|off`` Allocate auxiliary guest RAM as an anonymous file that is shareable with an external process. This option applies to -- 2.49.0