From nobody Mon Feb 9 20:31:27 2026 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=1695723087; cv=none; d=zohomail.com; s=zohoarc; b=SOe1UAO9WFL5DYpXZc60YI0tssyD88PVqTL0KxjJMm1NTpP7hK5qJzOJH26vPpiY4Sl9t4ObD91Nigqbi4y1MW3iCYy0UQutBFbMC+RErVShqEdVUqMmiXQYWeaeayKeOo5a1Wb0Uod+eD/D2sfFc+CRfYmOFalsgqLFYUhj3Jo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1695723087; h=Content-Type:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Reply-To:References:Sender:Subject:To; bh=6ssm8msVI3HRb5k8ZEe+7xWhpWkSgBFbRLcWAJxEyps=; b=TP0pPDLIi5Sp/ZcNmL+tt5u8gaapgT0NakVSei5aJyJ40PZN1L9S44e+H4Ab4/adgTofO70OjVI4j1Mvp3SZn2lsUD1CuB7CvM8buKsy+kUKfKMwPNttuBccqGnr5pg/qCk7kjEJT+/S/ibcMLzI5vHmx040mTmr/NtCK5khQEI= 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 1695723086613800.7205793542045; Tue, 26 Sep 2023 03:11:26 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ql528-0007c4-FH; Tue, 26 Sep 2023 06:11:12 -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 1ql525-0007DA-1y; Tue, 26 Sep 2023 06:11:09 -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 1ql520-0004v6-Lk; Tue, 26 Sep 2023 06:11:08 -0400 Received: from lhrpeml500001.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4RvwSB4340z6D8bS; Tue, 26 Sep 2023 18:08:42 +0800 (CST) Received: from A190218597.china.huawei.com (10.126.174.16) by lhrpeml500001.china.huawei.com (7.191.163.213) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 26 Sep 2023 11:10:43 +0100 To: , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH RFC V2 18/37] arm/virt: Make ARM vCPU *present* status ACPI *persistent* Date: Tue, 26 Sep 2023 11:04:17 +0100 Message-ID: <20230926100436.28284-19-salil.mehta@huawei.com> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20230926100436.28284-1-salil.mehta@huawei.com> References: <20230926100436.28284-1-salil.mehta@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.126.174.16] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To lhrpeml500001.china.huawei.com (7.191.163.213) X-CFilter-Loop: Reflected 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_H5=0.001, RCVD_IN_MSPIKE_WL=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: 1695723088373100003 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" ARM arch does not allow CPUs presence to be changed [1] after kernel has bo= oted. Hence, firmware/ACPI/Qemu must ensure persistent view of the vCPUs to the G= uest kernel even when they are not present in the QoM i.e. are unplugged or are yet-to-be-plugged References: [1] Check comment 5 in the bugzilla entry Link: https://bugzilla.tianocore.org/show_bug.cgi?id=3D4481#c5 Signed-off-by: Salil Mehta --- cpus-common.c | 6 ++++++ hw/arm/virt.c | 7 +++++++ include/hw/core/cpu.h | 20 ++++++++++++++++++++ 3 files changed, 33 insertions(+) diff --git a/cpus-common.c b/cpus-common.c index 24c04199a1..d64aa63b19 100644 --- a/cpus-common.c +++ b/cpus-common.c @@ -128,6 +128,12 @@ bool qemu_enabled_cpu(CPUState *cpu) return cpu && !cpu->disabled; } =20 +bool qemu_persistent_cpu(CPUState *cpu) +{ + /* cpu state can be faked to the guest via acpi */ + return cpu->acpi_persistent; +} + uint64_t qemu_get_cpu_archid(int cpu_index) { MachineState *ms =3D MACHINE(qdev_get_machine()); diff --git a/hw/arm/virt.c b/hw/arm/virt.c index cbb6199ec6..f1bee569d5 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -3006,6 +3006,13 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplu= g_dev, DeviceState *dev, return; } virt_cpu_set_properties(OBJECT(cs), cpu_slot, errp); + + /* + * To give persistent presence view of vCPUs to the guest, ACPI might = need + * to fake the presence of the vCPUs to the guest but keep them disabl= ed. + * This shall be used during the init of ACPI Hotplug state and hot-un= plug + */ + cs->acpi_persistent =3D true; } =20 static void virt_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev, diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h index b2201a98ee..dab572c9bd 100644 --- a/include/hw/core/cpu.h +++ b/include/hw/core/cpu.h @@ -425,6 +425,13 @@ struct CPUState { * By default every CPUState is enabled as of now across all archs. */ bool disabled; + /* + * On certain architectures, to give persistent view of the 'presence'= of + * vCPUs to the guest, ACPI might need to fake the 'presence' of the v= CPUs + * but keep them ACPI disabled to the guest. This is done by returning + * _STA.PRES=3DTrue and _STA.Ena=3DFalse for the unplugged vCPUs in QE= MU QoM. + */ + bool acpi_persistent; /* TODO Move common fields from CPUArchState here. */ int cpu_index; int cluster_index; @@ -814,6 +821,19 @@ bool qemu_present_cpu(CPUState *cpu); */ bool qemu_enabled_cpu(CPUState *cpu); =20 +/** + * qemu_persistent_cpu: + * @cpu: The vCPU to check + * + * Checks if the vCPU state should always be reflected as *present* via AC= PI + * to the Guest. By default, this is False on all architectures and has to= be + * explicity set during initialization. + * + * Returns: True if it is ACPI 'persistent' CPU + * + */ +bool qemu_persistent_cpu(CPUState *cpu); + /** * qemu_get_cpu_archid: * @cpu_index: possible vCPU for which arch-id needs to be retreived --=20 2.34.1