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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D59EC04AB4 for ; Fri, 17 May 2019 08:50:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F6C520833 for ; Fri, 17 May 2019 08:50:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RPF5qcEC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728625AbfEQIuD (ORCPT ); Fri, 17 May 2019 04:50:03 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:35521 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728481AbfEQIuA (ORCPT ); Fri, 17 May 2019 04:50:00 -0400 Received: by mail-pl1-f193.google.com with SMTP id g5so3056558plt.2; Fri, 17 May 2019 01:50:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=5VREHkPw8R8lwRxH+KVXuUktO+8MCxC49x2eL5UCIow=; b=RPF5qcECkRQX0J004+yKvh9PHjuDP9QRAl1CTIGwYdfFjC73ZOLGRcxDyItiIW7XyA nbv2F1mtgRdvb5ihxRpkb3z/RtFdWaS3jZoQtTHtuZuaN+M96WdPShDILNxokcxMGmK7 fRmgTv9Wt0N7ybh4BTAndZqH7yw/uUDNoe0JHoE3xA7owQGGbmrO/zzIsC10J4WDrEyJ WSfQKHZF4soeugQiLr5Qp2Kk1HO4TyKa5EWRgd2eL1cm66YKg1l6GYzikIeHsFV6SVXG cMYlPysB335VCYVBaSNNenhR8jQkxOVjEHMf0XmlklLT+MhhJ7V4gRkvDoXoX9NGDoMm 60dA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5VREHkPw8R8lwRxH+KVXuUktO+8MCxC49x2eL5UCIow=; b=TI1hwb2e8AuC8zzKWCHsFfPu3lqRQKdhO8xu1tWvk3LyOFbF4s+n5riZCwkm2s75Pc mKdKy3y2eNXFutAVycF5Wx9aTMfQ80uKlu3g8ZYtTz7J9AflsHHAwwmShbgIFuMVbX5Y 1ZRAUewCLVAcJJjtfgfAkuGxIGOuZboQLfKqe7UN42DivCQXs/fO+O7CA65iHPHWo9QQ ZY2Dk3jWdwRGlgTxc+EApwJHEWrpoYVZRQQgr1LU4XNHJlNW5KpSOUl6Pt4a/7+UDv/E 6ds7oe2QyBpiX6/tRxJFvMiOtTXV7uZNAz/ThrOSE1xlPptkUoSMW2GjgMPBQs5K8liq jccA== X-Gm-Message-State: APjAAAXjW/PQL+Kt8nqjjXn7Dh32PRx6yjdiYxGCc3fIpxYUkDgKqva3 gHhBEU36gnQx1lkiGYAMTOAfrOIe X-Google-Smtp-Source: APXvYqxe4n7YAE9tLJpT4f6BzKilEwXE3tVIRNBySLRokH+e3XoGXrD1560o4yN2vgR74SJe88LRlA== X-Received: by 2002:a17:902:aa95:: with SMTP id d21mr1072036plr.32.1558083000075; Fri, 17 May 2019 01:50:00 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.123]) by smtp.googlemail.com with ESMTPSA id 63sm10417127pfu.95.2019.05.17.01.49.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 17 May 2019 01:49:59 -0700 (PDT) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , "Paul E . McKenney" Subject: [PATCH 3/4] KVM: Fix spinlock taken warning during host resume Date: Fri, 17 May 2019 16:49:49 +0800 Message-Id: <1558082990-7822-3-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1558082990-7822-1-git-send-email-wanpengli@tencent.com> References: <1558082990-7822-1-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wanpeng Li WARNING: CPU: 0 PID: 13554 at kvm/arch/x86/kvm//../../../virt/kvm/kvm_main.c:4183 kvm_resume+0x3c/0x40 [kvm] CPU: 0 PID: 13554 Comm: step_after_susp Tainted: G OE 5.1.0-rc4+ #1 RIP: 0010:kvm_resume+0x3c/0x40 [kvm] Call Trace: syscore_resume+0x63/0x2d0 suspend_devices_and_enter+0x9d1/0xa40 pm_suspend+0x33a/0x3b0 state_store+0x82/0xf0 kobj_attr_store+0x12/0x20 sysfs_kf_write+0x4b/0x60 kernfs_fop_write+0x120/0x1a0 __vfs_write+0x1b/0x40 vfs_write+0xcd/0x1d0 ksys_write+0x5f/0xe0 __x64_sys_write+0x1a/0x20 do_syscall_64+0x6f/0x6c0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Commit ca84d1a24 (KVM: x86: Add clock sync request to hardware enable) mentioned that "we always hold kvm_lock when hardware_enable is called. The one place that doesn't need to worry about it is resume, as resuming a frozen CPU, the spinlock won't be taken." However, commit 6706dae9 (virt/kvm: Replace spin_is_locked() with lockdep) introduces a bug, it asserts when the lock is not held which is contrary to the original goal. This patch fixes it by WARN_ON when the lock is held. Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Paul E. McKenney 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 5fb0f16..c7eab5f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4096,7 +4096,7 @@ static int kvm_suspend(void) static void kvm_resume(void) { if (kvm_usage_count) { - lockdep_assert_held(&kvm_count_lock); + WARN_ON(lockdep_is_held(&kvm_count_lock)); hardware_enable_nolock(NULL); } } -- 2.7.4