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=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 6386AC2BC11 for ; Tue, 8 Sep 2020 22:44:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D68D2192A for ; Tue, 8 Sep 2020 22:44:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730435AbgIHWnT convert rfc822-to-8bit (ORCPT ); Tue, 8 Sep 2020 18:43:19 -0400 Received: from mga04.intel.com ([192.55.52.120]:10153 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730092AbgIHWnP (ORCPT ); Tue, 8 Sep 2020 18:43:15 -0400 IronPort-SDR: GJRUn/ojALcYr1RnQwXtJb4vfVpIM+iMYhTKEsRJJmSuR0QCKvnU2/cEV6emdqRBBj42WeNm51 +cj9GQRzvnnA== X-IronPort-AV: E=McAfee;i="6000,8403,9738"; a="155638268" X-IronPort-AV: E=Sophos;i="5.76,407,1592895600"; d="scan'208";a="155638268" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Sep 2020 15:43:14 -0700 IronPort-SDR: VZ4y8B/AwjLCLGKaGQt4gPJzvJIQTGKkkJh64Q92xroDBsUYzh0IFoEFRHaEMVDh+kwPWDc2xS 2lnl8/38qWWA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,407,1592895600"; d="scan'208";a="341345209" Received: from orsmsx606.amr.corp.intel.com ([10.22.229.19]) by FMSMGA003.fm.intel.com with ESMTP; 08 Sep 2020 15:43:13 -0700 Received: from orsmsx611.amr.corp.intel.com (10.22.229.24) by ORSMSX606.amr.corp.intel.com (10.22.229.19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Tue, 8 Sep 2020 15:43:13 -0700 Received: from orsmsx611.amr.corp.intel.com (10.22.229.24) by ORSMSX611.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Tue, 8 Sep 2020 15:43:12 -0700 Received: from orsmsx611.amr.corp.intel.com ([10.22.229.24]) by ORSMSX611.amr.corp.intel.com ([10.22.229.24]) with mapi id 15.01.1713.004; Tue, 8 Sep 2020 15:43:12 -0700 From: "Christopherson, Sean J" To: Ingo Molnar , Paolo Bonzini CC: "torvalds@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , Will Deacon Subject: RE: [GIT PULL] First batch of KVM changes for Linux 5.9 Thread-Topic: [GIT PULL] First batch of KVM changes for Linux 5.9 Thread-Index: AQHWa1ww4KOzvmpD9UyaU7UPqtFMUqlftQ+A///WEpA= Date: Tue, 8 Sep 2020 22:43:12 +0000 Message-ID: <6a83e6f1e9c34e44ae818ef88ec185a7@intel.com> References: <20200805182606.12621-1-pbonzini@redhat.com> <20200908180939.GA2378263@gmail.com> In-Reply-To: <20200908180939.GA2378263@gmail.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-version: 11.5.1.3 dlp-product: dlpe-windows dlp-reaction: no-action x-originating-ip: [10.1.200.100] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Ingo Molnar wrote: > * Paolo Bonzini wrote: > > > Paolo Bonzini (11): > > Merge branch 'kvm-async-pf-int' into HEAD > > kvmtool broke in this merge window, hanging during bootup right after CPU bringup: > > [ 1.289404] #63 > [ 0.012468] kvm-clock: cpu 63, msr 6ff69fc1, secondary cpu clock > [ 0.012468] [Firmware Bug]: CPU63: APIC id mismatch. Firmware: 3f APIC: 14 > [ 1.302320] kvm-guest: KVM setup async PF for cpu 63 > [ 1.302320] kvm-guest: stealtime: cpu 63, msr 1379d7600 > > Eventually trigger an RCU stall warning: > > [ 22.302392] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: > [ 22.302392] rcu: 1-...!: (68 GPs behind) idle=00c/0/0x0 softirq=0/0 fqs=0 (false positive?) > > I've bisected this down to the above merge commit. The individual commit: > > b1d405751cd5: ("KVM: x86: Switch KVM guest to using interrupts for page ready APF delivery") > > appears to be working fine standalone. > > I'm using x86-64 defconfig+kvmconfig on SVM. Can send more info on request. > > The kvmtool.git commit I've tested is 90b2d3adadf2. Looks a lot like the lack of APIC EOI issue that Vitaly reported[*]. --- arch/x86/kernel/kvm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index d45f34cbe1ef..9663ba31347c 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -271,6 +271,8 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt) struct pt_regs *old_regs = set_irq_regs(regs); u32 token; + ack_APIC_irq(); + inc_irq_stat(irq_hv_callback_count); if (__this_cpu_read(apf_reason.enabled)) { -- [*] https://lkml.kernel.org/r/20200908135350.355053-1-vkuznets@redhat.com