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 D093BC433F5 for ; Mon, 31 Jan 2022 11:42:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378431AbiAaLmh (ORCPT ); Mon, 31 Jan 2022 06:42:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378674AbiAaL24 (ORCPT ); Mon, 31 Jan 2022 06:28:56 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80CB9C0613E6; Mon, 31 Jan 2022 03:17:42 -0800 (PST) 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 2138061170; Mon, 31 Jan 2022 11:17:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5C07C340E8; Mon, 31 Jan 2022 11:17:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643627861; bh=k70UCGaKdelyUX4hLZO2WfvpGsnNzGI95PXnQiEeiXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EW2mhGLHNTSZ3wVMGR9aYxExye7r/wLCNp/5uc6zsfPG8gp5Hx/GeC6zlyUjgXqv+ QIZt3CUQwLLvNLRlFz9bKggaw5Uie/P6A71CIYynJ3siacc+KNInufCuovTFQHtWZ6 CEzvu4RZrMZpylxGW/vKub6lR7lfVkmOAbY1cikU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wanpeng Li , Paolo Bonzini Subject: [PATCH 5.16 048/200] KVM: LAPIC: Also cancel preemption timer during SET_LAPIC Date: Mon, 31 Jan 2022 11:55:11 +0100 Message-Id: <20220131105235.177585417@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220131105233.561926043@linuxfoundation.org> References: <20220131105233.561926043@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wanpeng Li commit 35fe7cfbab2e81f1afb23fc4212210b1de6d9633 upstream. The below warning is splatting during guest reboot. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1931 at arch/x86/kvm/x86.c:10322 kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm] CPU: 0 PID: 1931 Comm: qemu-system-x86 Tainted: G I 5.17.0-rc1+ #5 RIP: 0010:kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm] Call Trace: kvm_vcpu_ioctl+0x279/0x710 [kvm] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd39797350b This can be triggered by not exposing tsc-deadline mode and doing a reboot in the guest. The lapic_shutdown() function which is called in sys_reboot path will not disarm the flying timer, it just masks LVTT. lapic_shutdown() clears APIC state w/ LVT_MASKED and timer-mode bit is 0, this can trigger timer-mode switch between tsc-deadline and oneshot/periodic, which can result in preemption timer be cancelled in apic_update_lvtt(). However, We can't depend on this when not exposing tsc-deadline mode and oneshot/periodic modes emulated by preemption timer. Qemu will synchronise states around reset, let's cancel preemption timer under KVM_SET_LAPIC. Signed-off-by: Wanpeng Li Message-Id: <1643102220-35667-1-git-send-email-wanpengli@tencent.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2623,7 +2623,7 @@ int kvm_apic_set_state(struct kvm_vcpu * kvm_apic_set_version(vcpu); apic_update_ppr(apic); - hrtimer_cancel(&apic->lapic_timer.timer); + cancel_apic_timer(apic); apic->lapic_timer.expired_tscdeadline = 0; apic_update_lvtt(apic); apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0));