From patchwork Fri Nov 18 08:55:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dario Faggioli X-Patchwork-Id: 13047858 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 6DD9FC433FE for ; Fri, 18 Nov 2022 08:56:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ovx9x-0001ZP-3B; Fri, 18 Nov 2022 03:55:41 -0500 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 1ovx9w-0001Ym-32 for qemu-devel@nongnu.org; Fri, 18 Nov 2022 03:55:40 -0500 Received: from smtp-out2.suse.de ([2001:67c:2178:6::1d]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ovx9u-0002K9-8u for qemu-devel@nongnu.org; Fri, 18 Nov 2022 03:55:39 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 15C6E1F37F; Fri, 18 Nov 2022 08:55:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1668761736; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=LfdaOp+z78VCMVEbRfl2v6LJyloWFRkdGtZzuM7nSN0=; b=oUcTZeI3xkCTDqgL6bDXnT2+N3JWnP0zdIMO6nTzlGIAkmvGW/F12dkjHjLbAj4DhmhUfz 9XkpO6qN2qrPPReajpPZszpJu1JaqcaBYxs95b/6hC9wrGYPnHYBVZUaYM0WDZAszPS0yv ZeyhPuvGlUsNH2Jf2Rd8ax9li34g754= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id C816613A66; Fri, 18 Nov 2022 08:55:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id i7rbLodId2PfCAAAMHmgww (envelope-from ); Fri, 18 Nov 2022 08:55:35 +0000 Subject: [PATCH v2] pc: q35: Bump max_cpus to 1024 From: Dario Faggioli To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Richard Henderson , Eduardo Habkost , "Michael S. Tsirkin" , Marcel Apfelbaum Date: Fri, 18 Nov 2022 09:55:35 +0100 Message-ID: <166876173513.24238.8968021290016401421.stgit@tumbleweed.Wayrath> User-Agent: StGit/1.5 MIME-Version: 1.0 Received-SPF: pass client-ip=2001:67c:2178:6::1d; envelope-from=dfaggioli@suse.com; helo=smtp-out2.suse.de X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Keep the old limit of 288 for machine versions 7.2 and earlier. Signed-off-by: Dario Faggioli --- Cc: Paolo Bonzini Cc: Richard Henderson Cc: Eduardo Habkost Cc: "Michael S. Tsirkin" Cc: Marcel Apfelbaum --- Changes from v1: - fix actually keeping the old max value for the 7.2 machine type, which was the original goal, but was done wrongly --- This is related to: https://lore.kernel.org/qemu-devel/c705d0d8d6ed1a520b1ff92cb2f83fef19522d30.camel@suse.com/ With this applied to QEMU, I've been able to start a VM with as high as 980 vCPUs (even if I was on an host with 384 pCPUs, so everything was super slow!). After that, I started to see messages like this: "SMBIOS 2.1 table length 66822 exceeds 65535" Basing on the discussion happening in that thread, I'm going straight to 1024, as it seems to me that it's going to be working well soon (especially considering that this is meant for next release, not for 7.2) Thanks and Regards --- hw/i386/pc_q35.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index a496bd6e74..54804337e9 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -367,7 +367,7 @@ static void pc_q35_machine_options(MachineClass *m) machine_class_allow_dynamic_sysbus_dev(m, TYPE_INTEL_IOMMU_DEVICE); machine_class_allow_dynamic_sysbus_dev(m, TYPE_RAMFB_DEVICE); machine_class_allow_dynamic_sysbus_dev(m, TYPE_VMBUS_BRIDGE); - m->max_cpus = 288; + m->max_cpus = 1024; } static void pc_q35_7_2_machine_options(MachineClass *m) @@ -375,6 +375,7 @@ static void pc_q35_7_2_machine_options(MachineClass *m) PCMachineClass *pcmc = PC_MACHINE_CLASS(m); pc_q35_machine_options(m); m->alias = "q35"; + m->max_cpus = 288; pcmc->default_cpu_version = 1; }