From nobody Sat Nov 15 12:30:55 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass header.i=me@linux.beauty; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; arc=pass (i=1 dmarc=pass fromdomain=linux.beauty) ARC-Seal: i=2; a=rsa-sha256; t=1752665360; cv=pass; d=zohomail.com; s=zohoarc; b=ClHEjagexove2idip0fTzX20JqQOGcyXmEUUigesbLMs8iOdtKedg/W+CTZnUspG+5/Yc+vZASDTpHoUr0thc/MotkoqaIHEjQwSIObOnDtETYhHfzwu19Oy8UYUMylsdXilwR5cUcshrKTz2ANqR2mk3PUMt8rnI1jEno4g0wY= ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1752665360; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=PbWXELrNFK36KaZSrte+NesZIbPeFodr3uFNaBSeM1c=; b=Z00ZSFxrFGeRTnCKLswyKal0pwZAOueUr376eBVdXfnf0u8NNHEztaKksSRudWiTBc6HojEcY5SmR5mObztauUyElR+g2qcEOmkI0xYlAHAxAdXZ6numJTLwqKD+Y2xEGak+7LkhEJ9qSkX/AIwllOs1pLaeJnoIf0sqGc9PY1I= ARC-Authentication-Results: i=2; mx.zohomail.com; dkim=pass header.i=me@linux.beauty; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; arc=pass (i=1 dmarc=pass fromdomain=linux.beauty) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1752665360200751.658682443638; Wed, 16 Jul 2025 04:29:20 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uc0Hm-0006eg-W0; Wed, 16 Jul 2025 07:26:55 -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 1uc0CD-0001l0-LS; Wed, 16 Jul 2025 07:21:09 -0400 Received: from sender4-pp-f112.zoho.com ([136.143.188.112]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uc0CB-00013U-7B; Wed, 16 Jul 2025 07:21:09 -0400 Received: by mx.zohomail.com with SMTPS id 175266481068276.30808314738442; Wed, 16 Jul 2025 04:20:10 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1752664813; cv=none; d=zohomail.com; s=zohoarc; b=h56aqE1lIb4fXncE8zwikK5HSfeEQ27frip9S/5rz1s4+TAojxpIKXq2D+uFerkOUOZZ6IRu4DM9AT28YnM6qN5mjDLUfT3N2o5BI/tNlw73Tx3SKLR9Z9aY0VyVFmJHx7Xx2eMjH9cc1YGQTtKjeUtLZaOxgLPoFOxfvQCraBY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1752664813; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=PbWXELrNFK36KaZSrte+NesZIbPeFodr3uFNaBSeM1c=; b=IOAJ9X+mQYjZu6xNpcG+OcfoOvaXVXIiIR/QaNTLc9uDh2RT36YXFPhVWOfHTI+G+TaZko+r/NpL3XpGZ3j2jabVr+31bU6Cot9M94/QUd/eDafNVon4UUmjewKtRjk8otOikmV4c0wGW4vK9le7k5qqMeQpqORuoNnCmiYlovo= 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=1752664813; s=zmail; d=linux.beauty; i=me@linux.beauty; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=PbWXELrNFK36KaZSrte+NesZIbPeFodr3uFNaBSeM1c=; b=h47/argpBUdI3AXPYWmWqiB7+uk/6tPQPmfGRQg14THTlDNVE2viT4CunIBivE7B im4yz6hqBBzo/pg5eZJGHwGgUWSEhGKwgdzNZr4izDeyqkxzJNHpZ1RlDuv/R7cf2Em kEYcMO2orOrfNZSgRPPfceN0+Wxs8j0NZpzz40a4= From: Li Chen To: "Peter Maydell" , "Shannon Zhao" , "Michael S. Tsirkin" , "Igor Mammedov" , "Ani Sinha" , "Eduardo Habkost" , "Marcel Apfelbaum" , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , "Yanan Wang" , "Zhao Liu" , "Song Gao" , "Jiaxun Yang" , "Sunil V L" , "Palmer Dabbelt" , "Alistair Francis" , "Weiwei Li" , "qemu-arm" , "qemu-devel" , "qemu-riscv" Cc: Bibo Mao , Gavin Shan Subject: [PATCH v5 1/4] acpi: Add machine option to disable SPCR table Date: Wed, 16 Jul 2025 19:19:53 +0800 Message-ID: <20250716111959.404917-2-me@linux.beauty> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250716111959.404917-1-me@linux.beauty> References: <20250716111959.404917-1-me@linux.beauty> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ZohoMailClient: External Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=136.143.188.112; envelope-from=me@linux.beauty; helo=sender4-pp-f112.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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_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-devel@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-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity me@linux.beauty) X-ZM-MESSAGEID: 1752665361911116600 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=3DttyAMA0"), 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=3Doff By default, the option is enabled (spcr=3Don), 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 Reviewed-by: Sunil V L --- Notes: Changes since v3: 1. Add Reviewed-by from Sunil V L 2. rename enable_spcr to acpi_spcr_enabled as suggested by Philippe Mathieu-Daud=C3=A9 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 0dfb8ec2c3..782b17b966 100644 --- a/hw/arm/virt-acpi-build.c +++ b/hw/arm/virt-acpi-build.c @@ -1023,7 +1023,10 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuil= dTables *tables) } =20 acpi_add_table(table_offsets, tables_blob); - spcr_setup(tables_blob, tables->linker, vms); + + if (ms->acpi_spcr_enabled) { + spcr_setup(tables_blob, tables->linker, vms); + } =20 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 e869821b22..ceee058cad 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -577,6 +577,20 @@ static void machine_set_nvdimm(Object *obj, bool value= , Error **errp) ms->nvdimms_state->is_enabled =3D value; } =20 +static bool machine_get_spcr(Object *obj, Error **errp) +{ + MachineState *ms =3D MACHINE(obj); + + return ms->acpi_spcr_enabled; +} + +static void machine_set_spcr(Object *obj, bool value, Error **errp) +{ + MachineState *ms =3D MACHINE(obj); + + ms->acpi_spcr_enabled =3D value; +} + static bool machine_get_hmat(Object *obj, Error **errp) { MachineState *ms =3D MACHINE(obj); @@ -1281,6 +1295,14 @@ static void machine_initfn(Object *obj) "Table (HMAT)"); } =20 + /* SPCR */ + ms->acpi_spcr_enabled =3D true; + object_property_add_bool(obj, "spcr", machine_get_spcr, machine_set_sp= cr); + 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 =3D mc->default_cpus; ms->smp.max_cpus =3D mc->default_cpus; diff --git a/hw/loongarch/virt-acpi-build.c b/hw/loongarch/virt-acpi-build.c index 2cd2d9d842..8c2228a772 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, Machine= State *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->acpi_spcr_enabled) + spcr_setup(tables_blob, tables->linker, machine); =20 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 8b5683dbde..ee1416d264 100644 --- a/hw/riscv/virt-acpi-build.c +++ b/hw/riscv/virt-acpi-build.c @@ -894,7 +894,10 @@ static void virt_acpi_build(RISCVVirtState *s, AcpiBui= ldTables *tables) } =20 acpi_add_table(table_offsets, tables_blob); - spcr_setup(tables_blob, tables->linker, s); + + if (ms->acpi_spcr_enabled) { + spcr_setup(tables_blob, tables->linker, s); + } =20 acpi_add_table(table_offsets, tables_blob); { diff --git a/include/hw/boards.h b/include/hw/boards.h index f424b2b505..f94713e6e2 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -443,6 +443,7 @@ struct MachineState { SmpCache smp_cache; struct NVDIMMState *nvdimms_state; struct NumaState *numa_state; + bool acpi_spcr_enabled; }; =20 /* diff --git a/qemu-options.hx b/qemu-options.hx index 1f862b19a6..9b2d5f4b7a 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -38,6 +38,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ " nvdimm=3Don|off controls NVDIMM support (default=3Dof= f)\n" " memory-encryption=3D@var{} memory encryption object t= o use (default=3Dnone)\n" " hmat=3Don|off controls ACPI HMAT support (default=3Do= ff)\n" + " spcr=3Don|off controls ACPI SPCR support (default=3Do= n)\n" #ifdef CONFIG_POSIX " aux-ram-share=3Don|off allocate auxiliary guest RAM a= s shared (default: off)\n" #endif @@ -105,6 +106,10 @@ SRST Enables or disables ACPI Heterogeneous Memory Attribute Table (HMAT) support. The default is off. =20 + ``spcr=3Don|off`` + Enables or disables ACPI Serial Port Console Redirection Table + (SPCR) support. The default is on. + ``aux-ram-share=3Don|off`` Allocate auxiliary guest RAM as an anonymous file that is shareable with an external process. This option applies to --=20 2.50.0