From nobody Wed Oct 23 00:38:54 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; 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; dmarc=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1728987539; cv=none; d=zohomail.com; s=zohoarc; b=oDtRsmuzVeGwrZHPwLXlSS2Zh19A9yL/j2xacpTYVuN4INWhQCiDQFaSm+Y/J2PDu6iQJulW5J60W/jFHwxfsYG0CfFDlBoKhS0I845GFiBFyMb34CgEdHeBOT1vE+49ksAKIKDWs6G+PiFGrQyRGkk2z/wrI9iohE4dCm88ZpY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1728987539; 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:Reply-To:Reply-To:References:Sender:Subject:Subject:To:To:Message-Id; bh=EUplQQggQ5IxMmc5a0Tv3ZxPsR4daBO9cjnU+fSQFPk=; b=YO+edB1dPXQSJb826YTKV64MfbrdY8+V38OTNNy+xBlV5ZSUgRhDb1BkbYn8JmNqKBi7Cltp73fB6kUVUHms4PQ5mWE+KmZjW+r6FM9vfvYjrg8QWkg0hAkcY7BaUf5JNfJ27JYZ2CEIP3N7xWNkMr6YkgSqHH0vMbS1pW0+47s= ARC-Authentication-Results: i=1; mx.zohomail.com; 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; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1728987539344518.6315999565248; Tue, 15 Oct 2024 03:18:59 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t0ede-0004K2-3m; Tue, 15 Oct 2024 06:18:50 -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 1t0edV-0004EL-9R; Tue, 15 Oct 2024 06:18:42 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t0edT-0003l0-AG; Tue, 15 Oct 2024 06:18:41 -0400 Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4XSVQ356K0z6FGyW; Tue, 15 Oct 2024 18:16:59 +0800 (CST) Received: from frapeml500007.china.huawei.com (unknown [7.182.85.172]) by mail.maildlp.com (Postfix) with ESMTPS id E8EA91404F5; Tue, 15 Oct 2024 18:18:36 +0800 (CST) Received: from 00293818-MRGF.huawei.com (10.48.146.149) by frapeml500007.china.huawei.com (7.182.85.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 15 Oct 2024 12:18:17 +0200 To: , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH RFC V5 30/30] hw/arm/virt: Expose cold-booted vCPUs as MADT GICC *Enabled* Date: Tue, 15 Oct 2024 11:18:00 +0100 Message-ID: <20241015101800.254351-1-salil.mehta@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241015100012.254223-1-salil.mehta@huawei.com> References: <20241015100012.254223-1-salil.mehta@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.48.146.149] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To frapeml500007.china.huawei.com (7.182.85.172) 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=185.176.79.56; envelope-from=salil.mehta@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=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-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Salil Mehta From: Salil Mehta via Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1728987540361116600 Hotpluggable vCPUs must be exposed as "online-capable" according to the new= UEFI specification [1][2]. However, marking cold-booted vCPUs as "online-capable" during boot may cause them to go undetected by legacy operating systems, potentially leading to compatibility issues. Hence, both 'online-capable' b= it and 'Enabled' bit in GIC CPU Interface flags should not be mutually exclusi= ve as they are now. Since implementing this specification change may take time, it is necessary= to temporarily *disable* support for *unplugging* cold-booted vCPUs to maintain compatibility with legacy OS environments. As an alternative and temporary mitigation, we could introduce a property t= hat controls whether cold-booted vCPUs are marked as unpluggable. Community fee= dback on this approach would be appreciated. References: [1] Original UEFI/ACPI proposed Change Bugzilla =E2=80=93 TianoCore Link: https://bugzilla.tianocore.org/show_bug.cgi?id=3D3706 [2] Advanced Configuration and Power Interface (ACPI) Specification, Releas= e 6.5, Aug 29, 2022 Section: 5.2.12.14 GIC CPU Interface (GICC) Structure / Table 5.37: GIC= C CPU Interface Flags Link: https://uefi.org/sites/default/files/resources/ACPI_Spec_6_5_Aug2= 9.pdf (Pages 138, 140) Signed-off-by: Salil Mehta --- hw/arm/virt.c | 16 ++++++++++++++++ include/hw/core/cpu.h | 2 ++ 2 files changed, 18 insertions(+) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 15d9c2d8ac..d1172151be 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -3174,6 +3174,10 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplu= g_dev, DeviceState *dev, virt_update_gic(vms, cs, true); wire_gic_cpu_irqs(vms, cs); } + + if (!dev->hotplugged) { + cs->cold_booted =3D true; + } } =20 static void virt_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev, @@ -3248,6 +3252,18 @@ static void virt_cpu_unplug_request(HotplugHandler *= hotplug_dev, return; } =20 + /* + * UEFI ACPI standard change is required to make both 'enabled' and the + * 'online-capable' bit co-exist instead of being mutually exclusive. + * check virt_acpi_get_gicc_flags() for more details. + * + * Disable the unplugging of cold-booted vCPUs as a temporary mitigati= on. + */ + if (cs->cold_booted) { + error_setg(errp, "Hot-unplug of cold-booted CPU not supported!"); + return; + } + if (cs->cpu_index =3D=3D first_cpu->cpu_index) { error_setg(errp, "Boot CPU(id%d=3D%d:%d:%d:%d) hot-unplug not supp= orted", first_cpu->cpu_index, cpu->socket_id, cpu->cluster_id, diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h index 4a74c383ab..7b7ca2c32c 100644 --- a/include/hw/core/cpu.h +++ b/include/hw/core/cpu.h @@ -571,6 +571,8 @@ struct CPUState { uint32_t halted; int32_t exception_index; =20 + bool cold_booted; + AccelCPUState *accel; =20 /* Used to keep track of an outstanding cpu throttle thread for migrat= ion --=20 2.34.1