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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 CFA0DC4724C for ; Fri, 1 May 2020 20:18:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 987C12137B for ; Fri, 1 May 2020 20:18:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726488AbgEAUSi (ORCPT ); Fri, 1 May 2020 16:18:38 -0400 Received: from mga11.intel.com ([192.55.52.93]:43681 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbgEAUSh (ORCPT ); Fri, 1 May 2020 16:18:37 -0400 IronPort-SDR: KgY3oqt3PPtapMb+U91UqjGB7/Uyg/o+zT7SLAsVphlnG1NoxZlvzAujic8jclOvWAg93YHq0b Ce624zheFcww== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 May 2020 13:18:37 -0700 IronPort-SDR: hxrraMGFZU4NpRZqTnivv/G+Fa1fPCvrMCuNhSyVoJ8gQiqMJ40ejpUf6SaLfWFZudKbORQWTZ 74TfWVfb4lxg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,340,1583222400"; d="scan'208";a="460016158" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.152]) by fmsmga005.fm.intel.com with ESMTP; 01 May 2020 13:18:36 -0700 Date: Fri, 1 May 2020 13:18:36 -0700 From: Sean Christopherson To: Joshua Abraham Cc: pbonzini@redhat.com, corbet@lwn.net, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] docs: kvm: Fix KVM_KVMCLOCK_CTRL API doc Message-ID: <20200501201836.GB4760@linux.intel.com> References: <20200501193404.GA19745@josh-ZenBook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200501193404.GA19745@josh-ZenBook> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 01, 2020 at 03:34:06PM -0400, Joshua Abraham wrote: > The KVM_KVMCLOCK_CTRL ioctl signals to supported KVM guests > that the hypervisor has paused it. This updates the documentation > to reflect that the guest, not the host is notified by this API. No, the current documentation is correct. It's probably not as clear as it could be, but it's accurate as written. More below. > Signed-off-by: Joshua Abraham > --- > Documentation/virt/kvm/api.rst | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index efbbe570aa9b..06a4d9bfc6e5 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -2572,7 +2572,7 @@ list in 4.68. > :Parameters: None > :Returns: 0 on success, -1 on error > > -This signals to the host kernel that the specified guest is being paused by > +This signals to the guest kernel that the specified guest is being paused by > userspace. The ioctl() signals to the host kernel that host userspace has paused the vCPU. > The host will set a flag in the pvclock structure that is checked The host kernel, i.e. KVM, then takes that information and forwards it to the guest kernel via the aforementioned pvclock flag. The proposed change would imply the ioctl() is somehow getting routed directly to the guest, which is wrong. > from the soft lockup watchdog. The flag is part of the pvclock structure that > is shared between guest and host, specifically the second bit of the flags > -- > 2.17.1 >