From nobody Sat Nov 15 23:39:33 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=1745327336; cv=pass; d=zohomail.com; s=zohoarc; b=mYbKJ852pkE8kHUWKnjIlvvqCUm/9VnaPoocUnGxQY9e8/WOu7jBThgiJsd/OmTNNMOsymZ1hoxs3Pa7vzO0bXJhmXILBU3WIaX4iZdmzWrsp41C9aNAurYbMQX1ncESdsI2vl0DGJVtDCn687SXJlv4o/du5Sz9T41efyYHxac= ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1745327336; h=Content-Type:Date:Date:From:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:Subject:To:To:Message-Id:Reply-To:Cc; bh=1f6fhPG4bAKk0JZt43u8c0MdQmVwY/dIp/p0/C0Ji9o=; b=aMynMZ8+Rclrk/mi+BVMHh4OTEzzqMiqTkRh32cXDP9cPHfm4Ve7iYUspgt8TP/WV6w6tJJIu1vKeeXgRE0pdkm8xFxnDiGuf2IBno+71ZGnYa6hYYCTqZ0dM3hcG7HkTO1dyYEnDgoANeOoe52K9TKTT9JGqMahuSWTa2kexr4= 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 1745327336747196.91217175113718; Tue, 22 Apr 2025 06:08:56 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u7DLf-00049D-3I; Tue, 22 Apr 2025 09:07:39 -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 1u78PW-0000p5-60; Tue, 22 Apr 2025 03:51:18 -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 1u78PQ-0006e6-CH; Tue, 22 Apr 2025 03:51:15 -0400 Received: by mx.zohomail.com with SMTPS id 1745308231245860.2718604626467; Tue, 22 Apr 2025 00:50:31 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1745308234; cv=none; d=zohomail.com; s=zohoarc; b=P/kgcEwkpQQRfCAd7YqqnzxgppohP+jSKyqw7/XhF9yr71eDYoaCZRPwnn7Xb9z1Kve7P7QKO4fTIenhEu8TXiFuTOiqhr+KpXWIi9i8UkFajKa5LTBf9/SWjB/TdEDtjPEwymVqa+OAmdsNjf7zbLLG1ewpRlSX6iiOByaOUPc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1745308234; h=Content-Type:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To:Cc; bh=1f6fhPG4bAKk0JZt43u8c0MdQmVwY/dIp/p0/C0Ji9o=; b=F2RsFmyJyb9mgZsBBGTPEu7JEmk802msYgQogeaQTi36CcA152NSW+3RzzOo4jGujbngbPlzgMQW/X39le5p5NMOAtnKMSapfIvWP8MyCqo49WrERd8AskwDlSG9NHbJcCcydtSIiIJxe5ehK8d+HAgzjMIZZFoFcP8p2KRIC1w= 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=1745308233; s=zmail; d=linux.beauty; i=me@linux.beauty; h=Date:Date:Message-ID:From:From:To:To:Subject:Subject:MIME-Version:Content-Type:Message-Id:Reply-To:Cc; bh=1f6fhPG4bAKk0JZt43u8c0MdQmVwY/dIp/p0/C0Ji9o=; b=Ym0B7m6rWEbMAKn2VwRtfsqozZmAmjGTep86N+4h5lddXx8zvqHkoTGztdaGukLV 9Alolr5InuK+cB3SNzEL0xD6I6N7BFk+Jj5R/eYYXEC3NOfNFP8WotFfhtc+Odz09s9 RwxXxf7m78SBKMHAr5IeivvBGGLxvcS/UBrMyq2E= Date: Tue, 22 Apr 2025 15:47:18 +0800 Message-ID: <87a588wsc9.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 , Bibo Mao , Jiaxun Yang , Sunil V L , Palmer Dabbelt , Alistair Francis , Weiwei Li , qemu-arm@nongnu.org, qemu-devel@nongnu.org, qemu-riscv@nongnu.org Subject: [PATCH] acpi: Add machine option to disable SPCR table 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") 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=136.143.188.15; 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_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-Mailman-Approved-At: Tue, 22 Apr 2025 09:07:38 -0400 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: 1745327338188019000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 Acked-by: Michael S. Tsirkin Reviewed-by: Bibo Mao --- 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, AcpiBuildT= ables *tables) } =20 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); + } =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 63c6ef93d2..d56f44f4e8 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -590,6 +590,20 @@ 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->enable_spcr; +} + +static void machine_set_spcr(Object *obj, bool value, Error **errp) +{ + MachineState *ms =3D MACHINE(obj); + + ms->enable_spcr =3D value; +} + static bool machine_get_hmat(Object *obj, Error **errp) { MachineState *ms =3D MACHINE(obj); @@ -1294,6 +1308,14 @@ static void machine_initfn(Object *obj) "Table (HMAT)"); } =20 + /* SPCR */ + ms->enable_spcr =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 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, 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->enable_spcr) + 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 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, AcpiBui= ldTables *tables) build_rhct(tables_blob, tables->linker, s); =20 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); + } =20 acpi_add_table(table_offsets, tables_blob); { diff --git a/include/hw/boards.h b/include/hw/boards.h index f22b2e7fc7..cdf2791a50 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; }; =20 /* 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=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 2.49.0