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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 76ADFCA9EB9 for ; Wed, 23 Oct 2019 15:40:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4DC6F2086D for ; Wed, 23 Oct 2019 15:40:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390875AbfJWPkH (ORCPT ); Wed, 23 Oct 2019 11:40:07 -0400 Received: from mga12.intel.com ([192.55.52.136]:44407 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390140AbfJWPkH (ORCPT ); Wed, 23 Oct 2019 11:40:07 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Oct 2019 08:40:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,221,1569308400"; d="scan'208";a="201170699" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga003.jf.intel.com with ESMTP; 23 Oct 2019 08:40:06 -0700 Date: Wed, 23 Oct 2019 08:40:06 -0700 From: Sean Christopherson To: Zhenzhong Duan Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, pbonzini@redhat.com, rkrcmar@redhat.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, boris.ostrovsky@oracle.com, jgross@suse.com, peterz@infradead.org, will@kernel.org, linux-hyperv@vger.kernel.org, kvm@vger.kernel.org, mikelley@microsoft.com, kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, sashal@kernel.org, Jonathan Corbet , "H. Peter Anvin" Subject: Re: [PATCH v8 3/5] x86/kvm: Add "nopvspin" parameter to disable PV spinlocks Message-ID: <20191023154006.GN329@linux.intel.com> References: <1571829384-5309-1-git-send-email-zhenzhong.duan@oracle.com> <1571829384-5309-4-git-send-email-zhenzhong.duan@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1571829384-5309-4-git-send-email-zhenzhong.duan@oracle.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Wed, Oct 23, 2019 at 07:16:22PM +0800, Zhenzhong Duan wrote: > There are cases where a guest tries to switch spinlocks to bare metal > behavior (e.g. by setting "xen_nopvspin" on XEN platform and > "hv_nopvspin" on HYPER_V). > > That feature is missed on KVM, add a new parameter "nopvspin" to disable > PV spinlocks for KVM guest. > > The new 'nopvspin' parameter will also replace Xen and Hyper-V specific > parameters in future patches. > > Define variable nopvsin as global because it will be used in future > patches as above. > > Signed-off-by: Zhenzhong Duan > Reviewed-by: Vitaly Kuznetsov > Cc: Jonathan Corbet > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: "H. Peter Anvin" > Cc: Paolo Bonzini > Cc: Radim Krcmar > Cc: Sean Christopherson > Cc: Vitaly Kuznetsov > Cc: Wanpeng Li > Cc: Jim Mattson > Cc: Joerg Roedel > Cc: Peter Zijlstra > Cc: Will Deacon > --- Reviewed-by: Sean Christopherson