Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753219AbcKSTek (ORCPT ); Sat, 19 Nov 2016 14:34:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39192 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752414AbcKSTei (ORCPT ); Sat, 19 Nov 2016 14:34:38 -0500 Date: Sat, 19 Nov 2016 20:34:34 +0100 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Marcelo Tosatti Subject: Re: [PATCH] kvm: kvmclock: let KVM_GET_CLOCK return whether the master clock is in use Message-ID: <20161119193433.GG26213@potion> References: <1478710095-15022-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1478710095-15022-1-git-send-email-pbonzini@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Sat, 19 Nov 2016 19:34:38 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 588 Lines: 14 2016-11-09 17:48+0100, Paolo Bonzini: > Userspace can read the exact value of kvmclock by reading the TSC > and fetching the timekeeping parameters out of guest memory. This > however is brittle and not necessary anymore with KVM 4.11. Provide > a mechanism that lets userspace know if the new KVM_GET_CLOCK > semantics are in effect, and---since we are at it---if the clock > is stable across all VCPUs. > > Cc: Radim Krčmář > Cc: Marcelo Tosatti > Signed-off-by: Paolo Bonzini > --- Applied to kvm/master, thanks.