From nobody Wed Dec 17 09:44:29 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DC60C001DF for ; Fri, 20 Oct 2023 15:13:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377645AbjJTPNA (ORCPT ); Fri, 20 Oct 2023 11:13:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377631AbjJTPM5 (ORCPT ); Fri, 20 Oct 2023 11:12:57 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 137A2D60 for ; Fri, 20 Oct 2023 08:12:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697814776; x=1729350776; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3y5HBaCbruvZDuSXbdYk2vE0ssqVScSk0E4lneENlsY=; b=OA67ho2f3XyDZjWR/DXxT8D7+WSHYel4yamtCsd/uEBz3xudt4C2kN9g GYayaIQ0icpYcvQDijIFH9UscSqiYMQl8CZQm3O7cY3K2HK0kcaG4ZUPM UdAXuzLXP8/aFiHBzHDSASOEy1hUnwEWyLcUFkIe+EC/avPzfjsz3nla/ TkANF+qN8Ub6+J7l/ZdCl5xCA7kYDuSvALB3wCynoSR0ixkiW622171pJ 6Q6fqCi2gbKO1QdznIJiN9EALuP4hoDf0VBMXnQsBvbXveYTR+3eKUuUn jnbog+MF/DIoMUqSqoa00g23PwJwXyS6DJKJ1wuBAEqaHJtBdD+1sTams g==; X-IronPort-AV: E=McAfee;i="6600,9927,10869"; a="376893594" X-IronPort-AV: E=Sophos;i="6.03,239,1694761200"; d="scan'208";a="376893594" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2023 08:12:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10869"; a="761080243" X-IronPort-AV: E=Sophos;i="6.03,239,1694761200"; d="scan'208";a="761080243" Received: from dgutows1-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.249.39.237]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2023 08:12:49 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 0648110A295; Fri, 20 Oct 2023 18:12:45 +0300 (+03) From: "Kirill A. Shutemov" To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "Huang, Kai" , Baoquan He , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv2 03/13] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup Date: Fri, 20 Oct 2023 18:12:32 +0300 Message-ID: <20231020151242.1814-4-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231020151242.1814-1-kirill.shutemov@linux.intel.com> References: <20231020151242.1814-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" ACPI MADT doesn't allow to offline CPU after it got woke up. Currently hotplug prevented based on the confidential computing attribute which is set for Intel TDX. But TDX is not the only possible user of the wake up method. Disable CPU offlining on ACPI MADT wakeup enumeration. Signed-off-by: Kirill A. Shutemov --- arch/x86/coco/core.c | 1 - arch/x86/kernel/acpi/madt_wakeup.c | 3 +++ include/linux/cc_platform.h | 10 ---------- kernel/cpu.c | 3 +-- 4 files changed, 4 insertions(+), 13 deletions(-) diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c index eeec9986570e..f07c3bb7deab 100644 --- a/arch/x86/coco/core.c +++ b/arch/x86/coco/core.c @@ -20,7 +20,6 @@ static bool noinstr intel_cc_platform_has(enum cc_attr at= tr) { switch (attr) { case CC_ATTR_GUEST_UNROLL_STRING_IO: - case CC_ATTR_HOTPLUG_DISABLED: case CC_ATTR_GUEST_MEM_ENCRYPT: case CC_ATTR_MEM_ENCRYPT: return true; diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt= _wakeup.c index 58cdfc0b6c0a..4bc1d5106afd 100644 --- a/arch/x86/kernel/acpi/madt_wakeup.c +++ b/arch/x86/kernel/acpi/madt_wakeup.c @@ -1,4 +1,5 @@ #include +#include #include #include #include @@ -75,6 +76,8 @@ int __init acpi_parse_mp_wake(union acpi_subtable_headers= *header, =20 acpi_mp_wake_mailbox_paddr =3D mp_wake->base_address; =20 + cpu_hotplug_disable_offlining(); + apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu); =20 return 0; diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h index cb0d6cd1c12f..d08dd65b5c43 100644 --- a/include/linux/cc_platform.h +++ b/include/linux/cc_platform.h @@ -80,16 +80,6 @@ enum cc_attr { * using AMD SEV-SNP features. */ CC_ATTR_GUEST_SEV_SNP, - - /** - * @CC_ATTR_HOTPLUG_DISABLED: Hotplug is not supported or disabled. - * - * The platform/OS is running as a guest/virtual machine does not - * support CPU hotplug feature. - * - * Examples include TDX Guest. - */ - CC_ATTR_HOTPLUG_DISABLED, }; =20 #ifdef CONFIG_ARCH_HAS_CC_PLATFORM diff --git a/kernel/cpu.c b/kernel/cpu.c index faebee0050a2..51c258f289ac 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1517,8 +1517,7 @@ static int cpu_down_maps_locked(unsigned int cpu, enu= m cpuhp_state target) * If the platform does not support hotplug, report it explicitly to * differentiate it from a transient offlining failure. */ - if (cc_platform_has(CC_ATTR_HOTPLUG_DISABLED) || - cpu_hotplug_offline_disabled) + if (cpu_hotplug_offline_disabled) return -EOPNOTSUPP; if (cpu_hotplug_disabled) return -EBUSY; --=20 2.41.0