From patchwork Thu Jun 13 23:36:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Salil Mehta X-Patchwork-Id: 13697616 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.gnu.org (lists.gnu.org [209.51.188.17]) (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 F3F1AC27C4F for ; Thu, 13 Jun 2024 23:39:56 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sHu2A-0005JY-Qn; Thu, 13 Jun 2024 19:39:11 -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 1sHu27-0005Il-IL; Thu, 13 Jun 2024 19:39:07 -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 1sHu25-00031Q-LD; Thu, 13 Jun 2024 19:39:07 -0400 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4W0dzJ075Cz6HJTn; Fri, 14 Jun 2024 07:34:20 +0800 (CST) Received: from lhrpeml500001.china.huawei.com (unknown [7.191.163.213]) by mail.maildlp.com (Postfix) with ESMTPS id 526FF140B63; Fri, 14 Jun 2024 07:39:02 +0800 (CST) Received: from 00293818-MRGF.china.huawei.com (10.195.245.24) by lhrpeml500001.china.huawei.com (7.191.163.213) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Fri, 14 Jun 2024 00:38:39 +0100 To: , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH RFC V3 03/29] hw/arm/virt: Limit number of possible vCPUs for unsupported Accel or GIC Type Date: Fri, 14 Jun 2024 00:36:13 +0100 Message-ID: <20240613233639.202896-4-salil.mehta@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240613233639.202896-1-salil.mehta@huawei.com> References: <20240613233639.202896-1-salil.mehta@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.195.245.24] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To lhrpeml500001.china.huawei.com (7.191.163.213) 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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 X-Patchwork-Original-From: Salil Mehta via From: Salil Mehta Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org If Virtual CPU Hotplug support does not exist on a particular Accel platform or ARM GIC version, we should limit the possible vCPUs to those available during boot time (i.e SMP CPUs) and explicitly disable Virtual CPU Hotplug support. Signed-off-by: Salil Mehta --- hw/arm/virt.c | 66 +++++++++++++++++++++++++++++---------------------- 1 file changed, 38 insertions(+), 28 deletions(-) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 11fc7fc318..3e1c4d2d2f 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -2082,8 +2082,6 @@ static void machvirt_init(MachineState *machine) unsigned int smp_cpus = machine->smp.cpus; unsigned int max_cpus = machine->smp.max_cpus; - possible_cpus = mc->possible_cpu_arch_ids(machine); - /* * In accelerated mode, the memory map is computed earlier in kvm_type() * to create a VM with the right number of IPA bits. @@ -2098,7 +2096,7 @@ static void machvirt_init(MachineState *machine) * we are about to deal with. Once this is done, get rid of * the object. */ - cpuobj = object_new(possible_cpus->cpus[0].type); + cpuobj = object_new(machine->cpu_type); armcpu = ARM_CPU(cpuobj); pa_bits = arm_pamax(armcpu); @@ -2113,6 +2111,43 @@ static void machvirt_init(MachineState *machine) */ finalize_gic_version(vms); + /* + * The maximum number of CPUs depends on the GIC version, or on how + * many redistributors we can fit into the memory map (which in turn + * depends on whether this is a GICv3 or v4). + */ + if (vms->gic_version == VIRT_GIC_VERSION_2) { + virt_max_cpus = GIC_NCPU; + } else { + virt_max_cpus = virt_redist_capacity(vms, VIRT_GIC_REDIST); + if (vms->highmem_redists) { + virt_max_cpus += virt_redist_capacity(vms, VIRT_HIGH_GIC_REDIST2); + } + } + + if (tcg_enabled() || hvf_enabled() || qtest_enabled() || + (vms->gic_version < VIRT_GIC_VERSION_3)) { + max_cpus = machine->smp.max_cpus = smp_cpus; + mc->has_hotpluggable_cpus = false; + if (vms->gic_version >= VIRT_GIC_VERSION_3) { + warn_report("cpu hotplug feature has been disabled"); + } + } + + if (max_cpus > virt_max_cpus) { + error_report("Number of SMP CPUs requested (%d) exceeds max CPUs " + "supported by machine 'mach-virt' (%d)", + max_cpus, virt_max_cpus); + if (vms->gic_version != VIRT_GIC_VERSION_2 && !vms->highmem_redists) { + error_printf("Try 'highmem-redists=on' for more CPUs\n"); + } + + exit(1); + } + + /* uses smp.max_cpus to initialize all possible vCPUs */ + possible_cpus = mc->possible_cpu_arch_ids(machine); + if (vms->secure) { /* * The Secure view of the world is the same as the NonSecure, @@ -2147,31 +2182,6 @@ static void machvirt_init(MachineState *machine) vms->psci_conduit = QEMU_PSCI_CONDUIT_HVC; } - /* - * The maximum number of CPUs depends on the GIC version, or on how - * many redistributors we can fit into the memory map (which in turn - * depends on whether this is a GICv3 or v4). - */ - if (vms->gic_version == VIRT_GIC_VERSION_2) { - virt_max_cpus = GIC_NCPU; - } else { - virt_max_cpus = virt_redist_capacity(vms, VIRT_GIC_REDIST); - if (vms->highmem_redists) { - virt_max_cpus += virt_redist_capacity(vms, VIRT_HIGH_GIC_REDIST2); - } - } - - if (max_cpus > virt_max_cpus) { - error_report("Number of SMP CPUs requested (%d) exceeds max CPUs " - "supported by machine 'mach-virt' (%d)", - max_cpus, virt_max_cpus); - if (vms->gic_version != VIRT_GIC_VERSION_2 && !vms->highmem_redists) { - error_printf("Try 'highmem-redists=on' for more CPUs\n"); - } - - exit(1); - } - if (vms->secure && (kvm_enabled() || hvf_enabled())) { error_report("mach-virt: %s does not support providing " "Security extensions (TrustZone) to the guest CPU",