From patchwork Mon Apr 7 13:24:27 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Petr_Van=C4=9Bk?= X-Patchwork-Id: 14040520 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.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 C04EAC369A3 for ; Mon, 7 Apr 2025 13:25:21 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.940124.1340004 (Exim 4.92) (envelope-from ) id 1u1mTO-0004dI-Qg; Mon, 07 Apr 2025 13:25:10 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 940124.1340004; Mon, 07 Apr 2025 13:25:10 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u1mTO-0004d9-Nh; Mon, 07 Apr 2025 13:25:10 +0000 Received: by outflank-mailman (input) for mailman id 940124; Mon, 07 Apr 2025 13:25:09 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u1mTN-0004Of-SL for xen-devel@lists.xenproject.org; Mon, 07 Apr 2025 13:25:09 +0000 Received: from gmmr-4.centrum.cz (gmmr-4.centrum.cz [46.255.227.205]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id b984b4fb-13b3-11f0-9ffb-bf95429c2676; Mon, 07 Apr 2025 15:25:08 +0200 (CEST) Received: from gmmr-4.centrum.cz (localhost [127.0.0.1]) by gmmr-4.centrum.cz (Postfix) with ESMTP id E9EEF6C60 for ; Mon, 7 Apr 2025 15:25:07 +0200 (CEST) Received: from antispam30.centrum.cz (antispam30.cent [10.30.208.30]) by gmmr-4.centrum.cz (Postfix) with ESMTP id E699F201A7B2 for ; Mon, 7 Apr 2025 15:25:07 +0200 (CEST) Received: from unknown (HELO gm-smtp11.centrum.cz) ([46.255.227.75]) by antispam30.centrum.cz with ESMTP; 07 Apr 2025 15:25:07 +0200 Received: from localhost.localdomain (ip-213-220-240-96.bb.vodafone.cz [213.220.240.96]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by gm-smtp11.centrum.cz (Postfix) with ESMTPSA id F2BC0100AE2A3; Mon, 7 Apr 2025 15:25:06 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: b984b4fb-13b3-11f0-9ffb-bf95429c2676 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=atlas.cz; s=mail; t=1744032307; bh=M/srLozqjowrKwxtWCSUenY0UgmwFAtRY3NtZmGhjoU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y0tXSlgkErRtODYBiUMGYNczgBWjKYFksC5143OmPUFkyQ0py/iJvocinpd0MJ7DR n0BuqzTbY/xeYcSWAURax2xclTD7SGgGJQLwWjG8Xc+nC3y7QqnxagS59kOe4GT+Hi xKLbtottagnJ/BxrCuTMYiu/tBzEFZwaJmMnImIA= X-CSE-ConnectionGUID: JocpOiqgRoW7s7bex2I8zA== X-CSE-MsgGUID: pHnCKEnUQlCmrY9o+Cl+1Q== X-ThreatScanner-Verdict: Negative X-IPAS-Result: A2EDAADz0PNn/0vj/y5aGQEBAQEBAQEBAQEBAQEBAQEBARIBAQEBAQEBAQEBAQFACYE3AwEBAQEBCwGDM4FxhFWRcmGLGIYzi2qBcwsPAQEBAQEBAQEBCS4WBAEBPwaEOAoCiyonNQgOAQIEAQEBAQMCAwEBAQEBAQEBAQ0BAQYBAQEBAQEGBgECgR2FNVOCYgGEAAIBAwEiDwFGEBgBDAImAgInLwYTgwKCMAEDMa0qgTIaAmXccAJJBVVkgSmBGi4BiE8BhHxwhHdCgg2BFYE7gT5vhBoBhAOCaQSDR4RTkgWKHUiBBRwDWSwBVRMNCgsHBYFsAzUMCy4VMkQ4HYF8g3KFOIIRggSJFYRaLU+Dbx1AAwsYDUgRLDcUGwY9AW4Hll+EDQcBWTR7dniQS7YLhCWETZUEh3caM5dSHgOSZJh+pEuEaIFoAYIUMyIwgyJSGY48FhbMAXY8AgcBCgEBAwmCO40tATOBSwEB IronPort-PHdr: A9a23:BaswThdmsij45968CuU390jxlGM+7djLVj580XLHo4xHfqnrxZn+J kuXvawr0ASTG92DoKgc07CG+4nbGkU+or+5+EgYd5JNUxJXwe43pCcHROOjNwjQAcWuURYHG t9fXkRu5XCxPBsdMs//Y1rPvi/6tmZKSV3wOgVvO+v6BJPZgdip2OCu4Z3TZBhDiCagbb9oI xi7oxvdutMKjYd+Jao91AfFrmdWd+lV2GhlOU+dkxHg68i/+5Ju7z5esO87+c5aVqX6caU4T bhGAzkjLms4+s7luwTdQAWW/ncSXX0YnRVRDwXb4x/0Q4/9vSTmuOVz3imaJtD2QqsvWTu+9 adrSQTnhzkBOjUk7WzYkM1wjKZcoBK8uxxyxpPfbY+JOPZieK7WYMgXTnRdUMlPSyNBA5u8b 4oRAOoHIeZYtJT2q18XoRejGQWgGObjxzlVjXH0wKI6yfwsHwHY0gE+AtwAvnfaotL3O6ccX u+60KbGwC7fb/5Vwzrx9JLFfgwjrPyKQLl+cdDRyU4qFw7dlFuft5DlPymI3esCqWeb6fRlV eGygGMgsQ5xuDuvyd0piobTnIIY0UrL9Tl9wIkvPt20UlJ0YN+9HZZWqiqVOJd4TNk4TGF0p CY11KcGuZijcSQX1JgqyB7RZ+GDfoaI/x/uSOafLzh3iX9meb+yiBm//0ijx+DiWce501RHo yREn9TMuX0Byh/e58qGR/dg/Uqs3yuE2QPL6uxcLk05lLDXJ4Ahz7MwjJYfr1rPEy3slEj0j KKablso9vWm5uj9fLnquIOQO5VqhgzxLqgigMiyDOU+PwMTRWaU4/6826fm/UDhRbVKieA5n bfBvZDBIMQbura5AwhI0oY/8xq/Dymp0NAfnXQfI1JFfQuLj5PsO1HSOPD0EOqzj06wnzh1w fDGIqfhAojILnTZjLjgfK5x609ayAUt0dBS/51ZB7AbLP7tWkL8tMbUAgEnPwG22erqCtVw2 psbWW2VA6+ZNK3SsUWP5uIqO+SDfpUVuDXnJPgg/fHul2Q0lkUBfamtx5QXc2q0EehnIkmBe 3rjns8BEXsWvgo5VOHlkkeCUT1JaHa3Ra08/Co2B5i6DYfHXI+tm6aN0zu6H5FOfGBJFkiME Wv0d4WDQ/oDciSSLdJ7kjMaW7mtUZMu1RaptA/i1bVnNOTZ9zYEupLiyNh1/ezTlB4o+TNoC MSd1nmBT3tokWMQWz82wKd/rFRyy1qA0KV1mP9YGsJJ5/NPTAg6MYTQz+tgC9D9Qg7BZMuGS E66QtW6BjE8Vs4xw9AKY0dyANiiihHD3yy3A78JjbyLA5o08qPT3nTrOsly1W7K1LM9gFk+X stPKWqmi7Zw9gfNAY7FiliWmLi0dasC2C7A72ODzWuVvEFESw58S6rEUm4ZZkvOt9T54UHCQ KGyBrQ7KAdBztSCKqRSZt3zkVpGXOvjOMjZY2+pmWewCgyIxrSXbIrxYGgdxzjdCFManAwJ4 XmGMg0+Cj+7o23CFDxuCU7vY0T0/Ol6qXO7SFI0zg6TY0J7y7W14h8ViOeCS/McwL0Eoj0tq zZqE1an2dLZFd6AqxBmfKVGbtMx+E1H2n7BtwxhIpygKLhvhlofcwRxokPv2Ax7CoZensgwq nMl0g5yJLmG0FNOaTyYx4r8Or7JJWno+hCgdarW1kvZ0NaM9adcoMg//mnjuwSgDQIN93hmw 99YyTPI+prOHCIWUJTsTlww8Rlq4b3XNHoT/YTRgEVhLbP8jDbEeNFhUOI/yR+lds13Ob+AH RS0GN9MVJvmE/Ajh1X8NkFMB+tV7qNhepr+L5O7 IronPort-Data: A9a23:ws5s2qz7AqqBuXO7cth6t+fKxyrEfRIJ4+MujC+fZmUNrF6WrkVWz 2YcUD+PPf2JZzTyKtF+aoywo0pVusOEyNRnSgNu+FhgHilAwSbn6XV1DatS0we6dJCroJdPt p1GAjX4BJlpCCKa/1H1b+WJQUBUjcmgXqD7BPPPJhd/TAplTDZJoR94kobVuKYx6TSCK13L4 I6aT/H3Ygf/hmYoaj1Mt8pvlTs21BjMkGJF1rABTa8T1LPuvyF9JI4SI6i3M0z5TuF8dsamR /zOxa2O5WjQ+REgELuNyt4XpWVXKlJ6FVHmZkt+A8BOsDAbzsAB+vpT2M4nVKtio27hc+ZZk 4wR6MPqGW/FCYWX8AgVe0Ew/yiTpsSq8pefSZS0mZT7I0Er7xIAahihZa07FdRwxwp5PY1B3 d4fIygqbwmMveWJn6nkQOR83OVzPuC+aevzulk4pd3YJfkjBIvGX72TvJlT0TEsnN1LW/3MD yYbQWYxKk6dPlsVYAhRV89WcOSA3xETdxVRslGcoKMty2HPyAVqlrP/WDbQUofTH5QJwRbF+ woq+UzhIhcxF/GZ9AOB2Xe2t77I3gj/G9srQejQGvlCxQf7KnYoIBQMVlK+qOORg1K6UskZI F580iMoobI/6wqgSd7lUgfjiHWFogQdS5xbFOhSwBHdlILX7hyfC2xCSSROAPQ6u8smbTgr0 EKVhdTvBCwpvLD9YWKQ8PKYoC2/PQARLHQefmkUQA0d+d7hrYovyBXVQb5LEqGvicbuMSrt2 D3Mpy87750XjMgWx+Cy9kjGqyyjq4KPTQMv4AjTGGW/4WtRYI+jepzt6lXB6/tEBJiWQ0PHv 3UencWaqucUAvmljzCESuEANK+m6uzDMzDGh1NrWZ47+FyQF2WLId4WumwjYh0zbYBbJFcFf XPuhO+Y37cLVFPCUEO9S9/Z5xgCpUQ4KenYaw== IronPort-HdrOrdr: A9a23:wZCehaMFyYxuqsBcTsyjsMiBIKoaSvp037Dk7SxMoHtuA6ulfq GV7ZAmPHDP5gr5NEtLpTnEAtjifZq+z+8R3WByB9aftWDd0QPCEGgh1/qB/9SKIULDH4BmuJ uIC5IfNOHN X-Talos-CUID: 9a23:d87GiGz6gwMWXhBoyF7GBgU2Hcs9VXzEw03XHBCjVmxkWOe0GU25rfY= X-Talos-MUID: 9a23:Vt6T6wajnKiKdeBTrx/qrxJPMvpR54+rEnFcltYtv4rdDHkl X-IronPort-Anti-Spam-Filtered: true X-IronPort-AV: E=Sophos;i="6.15,194,1739833200"; d="scan'208";a="312947855" From: =?utf-8?q?Petr_Van=C4=9Bk?= To: Thomas Gleixner Cc: Andrew Cooper , arkamar@atlas.cz, Juergen Gross , linux-kernel@vger.kernel.org, stable@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org Subject: [PATCH v2 1/1] x86/acpi: Don't limit CPUs to 1 for Xen PV guests due to disabled ACPI Date: Mon, 7 Apr 2025 15:24:27 +0200 Message-ID: <20250407132445.6732-2-arkamar@atlas.cz> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250407132445.6732-1-arkamar@atlas.cz> References: <87ecy5wqjm.ffs@tglx> <20250407132445.6732-1-arkamar@atlas.cz> MIME-Version: 1.0 Xen disables ACPI for PV guests in DomU, which causes acpi_mps_check() to return 1 when CONFIG_X86_MPPARSE is not set. As a result, APIC is disabled and the guest is later limited to a single vCPU, despite being configured with more. This regression was introduced in version 6.9 in commit 7c0edad3643f ("x86/cpu/topology: Rework possible CPU management"), which added an early check that limits CPUs to 1 if apic_is_disabled. This patch updates acpi_mps_check() logic to return 0 early when running as a Xen PV guest in DomU, preventing APIC from being disabled in this specific case and restoring correct multi-vCPU behaviour. Fixes: 7c0edad3643f ("x86/cpu/topology: Rework possible CPU management") Cc: Thomas Gleixner Cc: x86@kernel.org Cc: xen-devel@lists.xenproject.org Cc: stable@vger.kernel.org # 6.9+ Signed-off-by: Petr Vaněk --- arch/x86/kernel/acpi/boot.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index dae6a73be40e..9fa321a95eb3 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -23,6 +23,8 @@ #include #include +#include + #include #include #include @@ -1729,6 +1731,15 @@ int __init acpi_mps_check(void) { #if defined(CONFIG_X86_LOCAL_APIC) && !defined(CONFIG_X86_MPPARSE) /* mptable code is not built-in*/ + + /* + * Xen disables ACPI in PV DomU guests but it still emulates APIC and + * supports SMP. Returning early here ensures that APIC is not disabled + * unnecessarily and the guest is not limited to a single vCPU. + */ + if (xen_pv_domain() && !xen_initial_domain()) + return 0; + if (acpi_disabled || acpi_noirq) { pr_warn("MPS support code is not built-in, using acpi=off or acpi=noirq or pci=noacpi may have problem\n"); return 1;