From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D518C7618B for ; Wed, 15 Mar 2023 12:26:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232339AbjCOM0r (ORCPT ); Wed, 15 Mar 2023 08:26:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232341AbjCOM0a (ORCPT ); Wed, 15 Mar 2023 08:26:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB8DD24CA4 for ; Wed, 15 Mar 2023 05:25:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 257EE61D43 for ; Wed, 15 Mar 2023 12:25:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 371AFC433EF; Wed, 15 Mar 2023 12:25:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678883103; bh=biaYvCVw5rGH8TYG36sinosiiqszprVrBjTgqBgErBE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YanvIR0ZYJR+hvJnrLtoVggkiA0r23brHZ/C9CJWIvQmXTio+J6WBKAseIPn7IPrp 1p2RlNAoM2l4A7T54/jBxgxPvV7VtRAO3w1nEbwJke8kPGIyPlHp+MHCjmmueRZluD i3mK8LnDyrjA9tFR4wC25N496GKNMpLloIl0PVXU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vitaly Kuznetsov , Sean Christopherson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.15 017/145] KVM: Pre-allocate cpumasks for kvm_make_all_cpus_request_except() Date: Wed, 15 Mar 2023 13:11:23 +0100 Message-Id: <20230315115739.564593447@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230315115738.951067403@linuxfoundation.org> References: <20230315115738.951067403@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vitaly Kuznetsov [ Upstream commit baff59ccdc657d290be51b95b38ebe5de40036b4 ] Allocating cpumask dynamically in zalloc_cpumask_var() is not ideal. Allocation is somewhat slow and can (in theory and when CPUMASK_OFFSTACK) fail. kvm_make_all_cpus_request_except() already disables preemption so we can use pre-allocated per-cpu cpumasks instead. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Message-Id: <20210903075141.403071-8-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini Stable-dep-of: 2b0128127373 ("KVM: Register /dev/kvm as the _very_ last thing during initialization") Signed-off-by: Sasha Levin --- virt/kvm/kvm_main.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d08dbf0be2fce..c60e88b0b24ec 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -157,6 +157,8 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm); static unsigned long long kvm_createvm_count; static unsigned long long kvm_active_vms; +static DEFINE_PER_CPU(cpumask_var_t, cpu_kick_mask); + __weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, unsigned long start, unsigned long end) { @@ -320,14 +322,15 @@ bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req, struct kvm_vcpu *except) { struct kvm_vcpu *vcpu; - cpumask_var_t cpus; + struct cpumask *cpus; bool called; int i, me; - zalloc_cpumask_var(&cpus, GFP_ATOMIC); - me = get_cpu(); + cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask); + cpumask_clear(cpus); + kvm_for_each_vcpu(i, vcpu, kvm) { if (vcpu == except) continue; @@ -337,7 +340,6 @@ bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req, called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT)); put_cpu(); - free_cpumask_var(cpus); return called; } @@ -5637,9 +5639,17 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, goto out_free_3; } + for_each_possible_cpu(cpu) { + if (!alloc_cpumask_var_node(&per_cpu(cpu_kick_mask, cpu), + GFP_KERNEL, cpu_to_node(cpu))) { + r = -ENOMEM; + goto out_free_4; + } + } + r = kvm_async_pf_init(); if (r) - goto out_free; + goto out_free_5; kvm_chardev_ops.owner = module; kvm_vm_fops.owner = module; @@ -5665,7 +5675,10 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, out_unreg: kvm_async_pf_deinit(); -out_free: +out_free_5: + for_each_possible_cpu(cpu) + free_cpumask_var(per_cpu(cpu_kick_mask, cpu)); +out_free_4: kmem_cache_destroy(kvm_vcpu_cache); out_free_3: unregister_reboot_notifier(&kvm_reboot_notifier); @@ -5685,8 +5698,12 @@ EXPORT_SYMBOL_GPL(kvm_init); void kvm_exit(void) { + int cpu; + debugfs_remove_recursive(kvm_debugfs_dir); misc_deregister(&kvm_dev); + for_each_possible_cpu(cpu) + free_cpumask_var(per_cpu(cpu_kick_mask, cpu)); kmem_cache_destroy(kvm_vcpu_cache); kvm_async_pf_deinit(); unregister_syscore_ops(&kvm_syscore_ops); -- 2.39.2