From patchwork Thu Sep 22 18:20:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Isaku Yamahata X-Patchwork-Id: 12985664 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 77B73C6FA82 for ; Thu, 22 Sep 2022 18:23:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232570AbiIVSX1 (ORCPT ); Thu, 22 Sep 2022 14:23:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232511AbiIVSWq (ORCPT ); Thu, 22 Sep 2022 14:22:46 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B0DC109608; Thu, 22 Sep 2022 11:21:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1663870919; x=1695406919; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=e6y3hm3ayzpDm9GqLzCdSOZ8vwYZDKw7HR+mXt4ONKk=; b=JdKoPH4gn0x+Waseq6+mHA1t/BQ16eTmtMy4bIVsc5n/JtLY+aLsOcTp zqBSs3VO8cZ2dSfjpzDVUqX1nos3wT6v/ojmoSMBvP+M1+08NmDJiiXBx OeHoy82E8f2AdNVmrJ89z0+GZddsvpapUuA5zmglfBHCOR5I7gI3G2bTB pwHehQZEmbkXtCyUBRk1zOAhLsFOUcMlwQvaVN0vU0s4ZWjCHqR+YWrVa 7C8apRa7hckKxux1J+emhLQoI8usm7WeAQBk3l5ASTBQJ45vQMhpQO75D PPQbMCIksIhDxei+bw4F8KQLel3SmewH6GL6bdyw8GJ7nr12EkV8mUkff w==; X-IronPort-AV: E=McAfee;i="6500,9779,10478"; a="326712904" X-IronPort-AV: E=Sophos;i="5.93,337,1654585200"; d="scan'208";a="326712904" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2022 11:21:23 -0700 X-IronPort-AV: E=Sophos;i="5.93,337,1654585200"; d="scan'208";a="653086790" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2022 11:21:23 -0700 From: isaku.yamahata@intel.com To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Marc Zyngier , Will Deacon Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Kai Huang , Chao Gao , Atish Patra , Shaokun Zhang , Daniel Lezcano , Huang Ying , Huacai Chen , Dave Hansen , Borislav Petkov Subject: [PATCH v5 19/30] KVM: kvm_arch.c: Remove a global variable, hardware_enable_failed Date: Thu, 22 Sep 2022 11:20:48 -0700 Message-Id: <7f85a41f7aaad91c062eef37669c1eda2632ba45.1663869838.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Isaku Yamahata A global variable hardware_enable_failed in kvm_arch.c is used only by kvm_arch_add_vm() and hardware_enable(). It doesn't have to be a global variable. Make it function local. Signed-off-by: Isaku Yamahata --- virt/kvm/kvm_arch.c | 61 ++++++++++++++++++++++----------------------- 1 file changed, 30 insertions(+), 31 deletions(-) diff --git a/virt/kvm/kvm_arch.c b/virt/kvm/kvm_arch.c index e6bf9de18cba..10fd29bdd6e1 100644 --- a/virt/kvm/kvm_arch.c +++ b/virt/kvm/kvm_arch.c @@ -13,7 +13,6 @@ #include static cpumask_t cpus_hardware_enabled = CPU_MASK_NONE; -static atomic_t hardware_enable_failed; /* * Called after the VM is otherwise initialized, but just before adding it to @@ -24,7 +23,7 @@ int __weak kvm_arch_post_init_vm(struct kvm *kvm) return 0; } -static void hardware_enable(void *junk) +static int __hardware_enable(void) { int cpu = raw_smp_processor_id(); int r; @@ -32,18 +31,22 @@ static void hardware_enable(void *junk) WARN_ON_ONCE(preemptible()); if (cpumask_test_cpu(cpu, &cpus_hardware_enabled)) - return; - - cpumask_set_cpu(cpu, &cpus_hardware_enabled); - + return 0; r = kvm_arch_hardware_enable(); - - if (r) { - cpumask_clear_cpu(cpu, &cpus_hardware_enabled); - atomic_inc(&hardware_enable_failed); + if (r) pr_warn("kvm: enabling virtualization on CPU%d failed during %pSb\n", cpu, __builtin_return_address(0)); - } + else + cpumask_set_cpu(cpu, &cpus_hardware_enabled); + return r; +} + +static void hardware_enable(void *arg) +{ + atomic_t *failed = arg; + + if (__hardware_enable()) + atomic_inc(failed); } static void hardware_disable(void *junk) @@ -64,15 +67,15 @@ static void hardware_disable(void *junk) */ int __weak kvm_arch_add_vm(struct kvm *kvm, int usage_count) { + atomic_t failed = ATOMIC_INIT(0); int r = 0; if (usage_count != 1) return 0; - atomic_set(&hardware_enable_failed, 0); - on_each_cpu(hardware_enable, NULL, 1); + on_each_cpu(hardware_enable, &failed, 1); - if (atomic_read(&hardware_enable_failed)) { + if (atomic_read(&failed)) { r = -EBUSY; goto err; } @@ -95,33 +98,29 @@ int __weak kvm_arch_del_vm(int usage_count) int __weak kvm_arch_online_cpu(unsigned int cpu, int usage_count) { - int ret = 0; + int ret; ret = kvm_arch_check_processor_compat(); if (ret) return ret; + if (!usage_count) + return 0; + + /* + * arch callback kvm_arch_hardware_enable() assumes that + * preemption is disabled for historical reason. Disable + * preemption until all arch callbacks are fixed. + */ + preempt_disable(); /* * Abort the CPU online process if hardware virtualization cannot * be enabled. Otherwise running VMs would encounter unrecoverable * errors when scheduled to this CPU. */ - if (usage_count) { - WARN_ON_ONCE(atomic_read(&hardware_enable_failed)); + ret = __hardware_enable(); + preempt_enable(); - /* - * arch callback kvm_arch_hardware_eanble() assumes that - * preemption is disabled for historical reason. Disable - * preemption until all arch callbacks are fixed. - */ - preempt_disable(); - hardware_enable(NULL); - preempt_enable(); - if (atomic_read(&hardware_enable_failed)) { - atomic_set(&hardware_enable_failed, 0); - ret = -EIO; - } - } return ret; } @@ -160,5 +159,5 @@ int __weak kvm_arch_suspend(int usage_count) void __weak kvm_arch_resume(int usage_count) { if (usage_count) - hardware_enable(NULL); + (void)__hardware_enable(); }