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=-12.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 820D5C4361A for ; Thu, 3 Dec 2020 14:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6AE622293 for ; Thu, 3 Dec 2020 14:35:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436525AbgLCOez (ORCPT ); Thu, 3 Dec 2020 09:34:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:57266 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728159AbgLCOez (ORCPT ); Thu, 3 Dec 2020 09:34:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607006009; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=6smsIvjf77OYufhjM+C0nrIBQuuSFafCoX7/LBefMiM=; b=gULYPi1uPCVBZnRipEt/DTz9hk356RosnjManBt2OlMXsHldmMwq6DCD2X2zoqHWupMyjO B5urZ28cLHZJHSgH5T6NofDAjDgHCcoaOg+ZBRfL0d12VcD92CQTcIR2LKYwDeHmPKXvxc Hy5lNo30+fJ4i2F6LGIN2wMMf3d6Pkw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-365-AOBA8ru4POGmZP_E6v16cw-1; Thu, 03 Dec 2020 09:33:27 -0500 X-MC-Unique: AOBA8ru4POGmZP_E6v16cw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 716B315822E; Thu, 3 Dec 2020 14:33:25 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id E723A18A60; Thu, 3 Dec 2020 14:33:20 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Sean Christopherson , Joerg Roedel , Ingo Molnar , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), "H. Peter Anvin" , Vitaly Kuznetsov , Paolo Bonzini , Borislav Petkov , Jim Mattson , Wanpeng Li , linux-kernel@vger.kernel.org, Thomas Gleixner , Maxim Levitsky Subject: [PATCH 0/1] Fix for a recent regression in kvm/queue (guest using 100% cpu time) Date: Thu, 3 Dec 2020 16:33:18 +0200 Message-Id: <20201203143319.159394-1-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org I did a quick bisect yesterday after noticing that my VMs started=0D to take 100% cpu time.=0D =0D Looks like we don't ignore SIPIs that are received while the CPU isn't=0D waiting for them, and that makes KVM think that CPU always has=0D pending events which makes it never enter an idle state.=0D =0D Best regards,=0D Maxim Levitsky=0D =0D Maxim Levitsky (1):=0D KVM: x86: ignore SIPIs that are received while not in wait-for-sipi=0D state=0D =0D arch/x86/kvm/lapic.c | 15 ++++++++-------=0D 1 file changed, 8 insertions(+), 7 deletions(-)=0D =0D -- =0D 2.26.2=0D =0D