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 C1988C433F5 for ; Sat, 29 Jan 2022 12:52:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348923AbiA2Mwz (ORCPT ); Sat, 29 Jan 2022 07:52:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347906AbiA2Mww (ORCPT ); Sat, 29 Jan 2022 07:52:52 -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 A452AC061714 for ; Sat, 29 Jan 2022 04:52:52 -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 432D460C09 for ; Sat, 29 Jan 2022 12:52:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00B08C340E5; Sat, 29 Jan 2022 12:52:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643460771; bh=mjgy2BHKIowhmTZNWwX4sDxXD3Xe+YbgrBjoD/4OChQ=; h=Subject:To:Cc:From:Date:From; b=HuEflgSfiViNSm+Njuyw19qPE603Bx8THUmA2Gp7rFJyQuo17OsAdRvf5T5Cc5SWG OWOdy3GqA20u+pwfBO3TLuEfAF+dHJ/Y35WuG9nF9VIC7tUiXZrxH2DEd6fNFXquuh QCnjEXu28mB14ujq/RFX+HL+PKYa7iY1mV6GuyZg= Subject: FAILED: patch "[PATCH] KVM: LAPIC: Also cancel preemption timer during SET_LAPIC" failed to apply to 5.10-stable tree To: wanpengli@tencent.com, pbonzini@redhat.com Cc: From: Date: Sat, 29 Jan 2022 13:52:43 +0100 Message-ID: <1643460763231174@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 35fe7cfbab2e81f1afb23fc4212210b1de6d9633 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Tue, 25 Jan 2022 01:17:00 -0800 Subject: [PATCH] KVM: LAPIC: Also cancel preemption timer during SET_LAPIC 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 diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index baca9fa37a91..4662469240bc 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2629,7 +2629,7 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) 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));