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 A3587C433F5 for ; Tue, 15 Feb 2022 16:26:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241550AbiBOQ1G (ORCPT ); Tue, 15 Feb 2022 11:27:06 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:33404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241544AbiBOQ1F (ORCPT ); Tue, 15 Feb 2022 11:27:05 -0500 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83B8F66F97 for ; Tue, 15 Feb 2022 08:26:53 -0800 (PST) Received: by mail-pj1-x1035.google.com with SMTP id v8-20020a17090a634800b001bb78857ccdso1117382pjs.1 for ; Tue, 15 Feb 2022 08:26:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=4AlrkeeOh0/Ufcc3UhsLjdJdRVpoM+riWwT9RuQlIRU=; b=d0pWAwFclxXSjZn3YA4K8V/CwPcWGI1yTN7bKBa+B683NUF8r5WKYsm+VGWk7Vqaez eTDpe4b4sWabolPl84kzQWLnIryk75cvpwhx2vHaq12wHPi7IgJ+ljgw5QChAU6b5KGs MUQQtkJ/4tjH/8foiyaxX4P+jQnNGaAQ0nH+3PY2H8gezxYZRMALMexDENJVdWb+uMVo c4aV+Hs0FpOVSU4MRhW+Rmo3C9OAtWlmSmAe/5zkGSHJNUI7lEIjhFjcy2ltYGPlx4Rz 2UFm0jzGVjjjUg9G6lONM41KO33LGQH0Mh/CJNrLs7WjgctuadQu5dImAX0RerSwTTAY C2/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=4AlrkeeOh0/Ufcc3UhsLjdJdRVpoM+riWwT9RuQlIRU=; b=QX0WkbX/LJk3g8B9ueXfsk8kpWH0DGXxw1Z3uwWGPbDSEj3P8rj3YsRzbJ3usPaNmT f/pApRclZsyedlkvBr29XxLEFbGm5TBhDazCN32E4DbIChsXFJaBokXLxJE9ZqorZDYb 7vTcM5OLJfAw5iIQG29rz9UjzEh9MKRl84b9nk1lRg39/vBepTbVaKadKNM+EwHV2BNQ XO++kZhr7fHhXnJnnGY8fC4EADcPJxhLtrvcSk1RMpUoDPYKfqcqv8Jm+NRfOIWGe2kI u7EDUL/geQPpczvN95SdvKzxx0I/QTtYo6l2an1WcFuVnnt9daLWW6qm8QiDcygjBGmL AgEQ== X-Gm-Message-State: AOAM532TgViEtCjY1ScEsaROltaVcs8NVWMcTI5vbDmXaZ/xQg0D5Qh7 aqoCsQ55mGNMcye/mgI7jJQgIQ== X-Google-Smtp-Source: ABdhPJzwgO018qz0B77mszx1CmVsyurVkt4dBBqXVTV6Jfw1+PjyE7MG5D5NZVyMRs+57WNG/ZcL2w== X-Received: by 2002:a17:902:ed89:: with SMTP id e9mr5235867plj.88.1644942412865; Tue, 15 Feb 2022 08:26:52 -0800 (PST) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id g6sm20404223pfv.158.2022.02.15.08.26.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Feb 2022 08:26:52 -0800 (PST) Date: Tue, 15 Feb 2022 16:26:48 +0000 From: Sean Christopherson To: Wanpeng Li Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: Re: [PATCH] KVM: Fix lockdep false negative during host resume Message-ID: References: <1644920142-81249-1-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1644920142-81249-1-git-send-email-wanpengli@tencent.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Feb 15, 2022, Wanpeng Li wrote: > From: Wanpeng Li > > I saw the below splatting after the host suspended and resumed. > > WARNING: CPU: 0 PID: 2943 at kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:5531 kvm_resume+0x2c/0x30 [kvm] > CPU: 0 PID: 2943 Comm: step_after_susp Tainted: G W IOE 5.17.0-rc3+ #4 > RIP: 0010:kvm_resume+0x2c/0x30 [kvm] > Call Trace: > > syscore_resume+0x90/0x340 > suspend_devices_and_enter+0xaee/0xe90 > pm_suspend.cold+0x36b/0x3c2 > state_store+0x82/0xf0 > kernfs_fop_write_iter+0x1b6/0x260 > new_sync_write+0x258/0x370 > vfs_write+0x33f/0x510 > ksys_write+0xc9/0x160 > do_syscall_64+0x3b/0xc0 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > lockdep_is_held() can return -1 when lockdep is disabled which triggers > this warning. Let's use lockdep_assert_not_held() which can detect > incorrect calls while holding a lock and it also avoids false negatives > when lockdep is disabled. > Fixes: 2eb06c306a57 ("KVM: Fix spinlock taken warning during host resume") > Signed-off-by: Wanpeng Li > --- > virt/kvm/kvm_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 83c57bcc6eb6..3f861f33bfe0 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -5528,7 +5528,7 @@ static void kvm_resume(void) > { > if (kvm_usage_count) { > #ifdef CONFIG_LOCKDEP The #ifdef can be dropped, it was added only to omit the WARN_ON. With that, Reviewed-by: Sean Christopherson > - WARN_ON(lockdep_is_held(&kvm_count_lock)); > + lockdep_assert_not_held(&kvm_count_lock); > #endif > hardware_enable_nolock(NULL); > } > -- > 2.25.1 >