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 4B888C6FD19 for ; Fri, 10 Mar 2023 22:14:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231326AbjCJWOX (ORCPT ); Fri, 10 Mar 2023 17:14:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231220AbjCJWOV (ORCPT ); Fri, 10 Mar 2023 17:14:21 -0500 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FC3A115DE5 for ; Fri, 10 Mar 2023 14:14:19 -0800 (PST) Received: by mail-pf1-x449.google.com with SMTP id cr10-20020a056a000f0a00b005cfec6c2354so3477931pfb.9 for ; Fri, 10 Mar 2023 14:14:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1678486459; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=pE0BeI9z8Btfvf5fmHYTFVBRcoqQtEODzvdHtDO3xCE=; b=nRb2x/Az02iItbQ3I1bSF4yJ9xu29h0hIwwWhVNSJNRSMZNeINtGtQihw8x/ogzEwj Vd5WHSRuHp58cuzg+TBKg88rjb8fidPwPHdxzg3JtQyhLzyp6UXqN+RgK2NB0Vv0eP8j RyIk8lIGN74xRgM5GkcSf7HJJDRvg87Kooip0b7WCcy3+vUFeTtDqXBYfFNpHldfChxg P5F6EEbuDxLxeqSmK6GaQy17ujAAN0c5HgbwydDUWLCR30mDFyMVo62MgbmKkdNIoQHG WWx2BBn6pbm6Ecxov3jmRE3kuoJEy5J0lX4KhD6cm6eJrDSn+8pst2PuKMNhZrxIxurE M/Ww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678486459; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=pE0BeI9z8Btfvf5fmHYTFVBRcoqQtEODzvdHtDO3xCE=; b=ZnS0qT5eMg9bwH+128sidppBrfYYzd/LPHhRkoFC3g95CCJEAUxP3nFQMJeFYeaVww b2zhKuOtUltLxcPw3wwD91EmcucxYQ99tK8LzOwfxKQjvvnaBecbtRn/3ysOCJMTgvVH aE1sGxMnKBbiOjrvrfNFv47cv1VzIXZ7bx/+GTDAmPVl5swmI45kle4g4OU4NNCRo9dg dTRhy0Ko4Bvs9Q2J+Ae88HNeQfjoPL1nym6si7NLd4R1kAciZPWwKPUk4IAAogEepbCx T//+nqfppYrEdxIjPzq9xFMjdNsZNJxT10/8yaZALAJpO4Kn7dI6NvWS+nBtFCdVlveQ hf6A== X-Gm-Message-State: AO0yUKV8JCuKC2PBcj0zvQ14kg1L00aKEaLrYDVvr8Yzja2nmYq5yuTt 3eRBzB7kSD490ui87MhqLo1xM0ntGU4= X-Google-Smtp-Source: AK7set/UaGZlFDNJJDtnC1S1I4yxriVlz2I1afrzyalSLmeX7FDonyxhmqzPFzIIW/vSmY89hMYR7KUSZJs= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:f783:b0:19e:2a1b:2798 with SMTP id q3-20020a170902f78300b0019e2a1b2798mr10477888pln.4.1678486458964; Fri, 10 Mar 2023 14:14:18 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 10 Mar 2023 14:14:13 -0800 In-Reply-To: <20230310221414.811690-1-seanjc@google.com> Mime-Version: 1.0 References: <20230310221414.811690-1-seanjc@google.com> X-Mailer: git-send-email 2.40.0.rc1.284.g88254d51c5-goog Message-ID: <20230310221414.811690-2-seanjc@google.com> Subject: [PATCH 1/2] KVM: Use syscore_ops instead of reboot_notifier to hook restart/shutdown From: Sean Christopherson To: Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , kvmarm@lists.linux.dev, Huacai Chen , Aleksandar Markovic , Anup Patel , Atish Patra , kvm-riscv@lists.infradead.org, Sean Christopherson Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Use syscore_ops.shutdown to disable hardware virtualization during a reboot instead of using the dedicated reboot_notifier so that KVM disables virtualization _after_ system_state has been updated. This will allow fixing a race in KVM's handling of a forced reboot where KVM can end up enabling hardware virtualization between kernel_restart_prepare() and machine_restart(). Cc: Marc Zyngier Cc: Oliver Upton Cc: James Morse Cc: Suzuki K Poulose Cc: Zenghui Yu Cc: kvmarm@lists.linux.dev Cc: Huacai Chen Cc: Aleksandar Markovic Cc: Anup Patel Cc: Atish Patra Cc: kvm-riscv@lists.infradead.org Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d255964ec331..6cdfbb2c641b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -5211,8 +5211,7 @@ static int hardware_enable_all(void) return r; } -static int kvm_reboot(struct notifier_block *notifier, unsigned long val, - void *v) +static void kvm_reboot(void) { /* * Some (well, at least mine) BIOSes hang on reboot if @@ -5223,14 +5222,8 @@ static int kvm_reboot(struct notifier_block *notifier, unsigned long val, pr_info("kvm: exiting hardware virtualization\n"); kvm_rebooting = true; on_each_cpu(hardware_disable_nolock, NULL, 1); - return NOTIFY_OK; } -static struct notifier_block kvm_reboot_notifier = { - .notifier_call = kvm_reboot, - .priority = 0, -}; - static int kvm_suspend(void) { /* @@ -5261,6 +5254,8 @@ static void kvm_resume(void) static struct syscore_ops kvm_syscore_ops = { .suspend = kvm_suspend, .resume = kvm_resume, + .shutdown = kvm_reboot, + }; #else /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */ static int hardware_enable_all(void) @@ -5967,7 +5962,6 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) if (r) return r; - register_reboot_notifier(&kvm_reboot_notifier); register_syscore_ops(&kvm_syscore_ops); #endif @@ -6039,7 +6033,6 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) err_vcpu_cache: #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING unregister_syscore_ops(&kvm_syscore_ops); - unregister_reboot_notifier(&kvm_reboot_notifier); cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE); #endif return r; @@ -6065,7 +6058,6 @@ void kvm_exit(void) kvm_async_pf_deinit(); #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING unregister_syscore_ops(&kvm_syscore_ops); - unregister_reboot_notifier(&kvm_reboot_notifier); cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE); #endif kvm_irqfd_exit(); -- 2.40.0.rc1.284.g88254d51c5-goog