From nobody Wed Oct 23 00:40:43 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=1728986949; cv=none; d=zohomail.com; s=zohoarc; b=Osj9lCDNyy1FL0ZZ96diwY4R8/rhmyVEAw9t2plQ9IVOE2Qn52JkCUFzbobJjalyFOUtJfS8PI6T911SGLBGHVxCinefbE9BGKHtV9FMWlSGL7zLnnjgswLn00x/Tt6FIImgJqGGLTSwWdDzfpWHDdqt92VumS2+nCima5+w03U= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1728986949; 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=hU2CgzHJK/NinSmOpsUpBycxo19a8SSsqHQc9c/g8Io=; b=g5Ks3nInluQ+60XrHFWGWNj6QHTqoZQI8rHLP5tAuCHTCjEI4ubL2nURh2xAlCu3FR4GsUI7wv16b7qaOPtEB+zAksvMUH2GFvN4D5KHyWwH/1Ih4UPHM65CojlGUpcYFZMVBFzJyqLCT/onwXehh65Ux51JDHYzHJtM/xDvPPM= 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 1728986949451612.2858605988899; Tue, 15 Oct 2024 03:09:09 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t0eTg-0005CU-DJ; Tue, 15 Oct 2024 06:08:32 -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 1t0eTc-0004ww-A2; Tue, 15 Oct 2024 06:08:28 -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 1t0eTa-0002H4-KK; Tue, 15 Oct 2024 06:08:28 -0400 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4XSVBH21j1z6F97V; Tue, 15 Oct 2024 18:06:47 +0800 (CST) Received: from frapeml500007.china.huawei.com (unknown [7.182.85.172]) by mail.maildlp.com (Postfix) with ESMTPS id 7CB55140519; Tue, 15 Oct 2024 18:08:24 +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 12:08:04 +0200 To: , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH RFC V5 22/30] target/arm/cpu: Check if hotplugged ARM vCPU's FEAT match existing Date: Tue, 15 Oct 2024 11:00:04 +0100 Message-ID: <20241015100012.254223-23-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-Transfer-Encoding: quoted-printable X-Originating-IP: [10.48.146.149] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) 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: 1728986951516116600 Content-Type: text/plain; charset="utf-8" The ARM extensions configuration *must* match the existing vCPUs already initialized in KVM at VM initialization. ARM does not allow any per-vCPU features to be changed once the system has fully initialized. This is an immutable constraint of the ARM CPU architecture. Signed-off-by: Salil Mehta --- target/arm/cpu.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/target/arm/cpu.c b/target/arm/cpu.c index 3de0cb346b..14fcabc2c9 100644 --- a/target/arm/cpu.c +++ b/target/arm/cpu.c @@ -1912,6 +1912,49 @@ static void arm_cpu_finalizefn(Object *obj) #endif } =20 +static void arm_cpu_check_features_change(ARMCPU *cpu, Error **errp) +{ +#if defined(TARGET_AARCH64) && !defined(CONFIG_USER_ONLY) + MachineClass *mc =3D MACHINE_GET_CLASS(qdev_get_machine()); + ARMCPU *firstcpu =3D ARM_CPU(first_cpu); + DeviceState *dev =3D DEVICE(cpu); + + if (!arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) { + return; + } + + /* For now, features of hotplugged CPU MUST match earlier booted CPUs = */ + if (!dev->hotplugged || !mc->has_hotpluggable_cpus) { + return; + } + + if (cpu_isar_feature(aa64_sve, cpu) && + (cpu->sve_max_vq !=3D firstcpu->sve_max_vq || + cpu->sve_vq.map !=3D firstcpu->sve_vq.map)) { + error_setg(errp, + "CPU %d: 'SVE' feature didn't match with existing CPUs", + CPU(cpu)->cpu_index); + return; + } + + if (cpu_isar_feature(aa64_sme, cpu) && + (cpu->sme_vq.map !=3D firstcpu->sme_vq.map)) { + error_setg(errp, + "CPU %d: 'SME' feature didn't match with exisitng CPUs", + CPU(cpu)->cpu_index); + return; + } + + if (cpu_isar_feature(aa64_pauth, cpu) && + (cpu->prop_pauth !=3D firstcpu->prop_pauth)) { + error_setg(errp, + "CPU %d: 'PAuth' feature didn't match with exisitng CPU= s", + CPU(cpu)->cpu_index); + return; + } +#endif +} + void arm_cpu_finalize_features(ARMCPU *cpu, Error **errp) { Error *local_err =3D NULL; @@ -1961,6 +2004,13 @@ void arm_cpu_finalize_features(ARMCPU *cpu, Error **= errp) return; } } + + /* + * As of now, we do not support heterogeneous computing, hence, featur= es of + * all cpus should match. Hotplugged vCPUs are not allowed to have + * different features than the existing cold-plugged vCPUs + */ + arm_cpu_check_features_change(cpu, &local_err); } =20 static void arm_cpu_realizefn(DeviceState *dev, Error **errp) --=20 2.34.1