From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denis Plotnikov Subject: Re: [PATCH 0/2] maintaining of kvm_clock stability on guest vCPU hotplug Date: Thu, 6 Apr 2017 11:08:43 +0300 Message-ID: <1491466125-16988-1-git-send-email-dplotnikov@virtuozzo.com> Mime-Version: 1.0 Content-Type: text/plain; charset="y" Content-Transfer-Encoding: 8bit Cc: , , To: , , , Return-path: Received: from mail-he1eur01on0110.outbound.protection.outlook.com ([104.47.0.110]:59105 "EHLO EUR01-HE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753779AbdDFIJG (ORCPT ); Thu, 6 Apr 2017 04:09:06 -0400 Sender: kvm-owner@vger.kernel.org List-ID: the series sending repeated On 05.04.2017 17:23, Radim Krčmář wrote: > 2017-04-05 11:56+0300, Denis Plotnikov: >> ping > Please re-send the series, I don't have it in mailbox and web-archives > don't show it either, > > thanks. > >> On 23.03.2017 17:28, Denis Plotnikov wrote: >>> It was found, that after adding a new vCPU to a running VM (CPU hotplug) >>> kvm_clock lost the stability property in case of using it. This happened >>> because KVM didn't treated cpu hotplug as a special case of TSC >>> synchronization. >>> This patch series adds cpu hotplug to the TSC synchronization cases. > Right, it looks like an incarnation of the deep problem where the kvm > clock with masterclock diverges from host (different frequency), so any > case where the masterclock is synchronized results in time shifts in the > guest. > >>> Denis Plotnikov (2): >>> KVM: x86: remaster kvm_write_tsc code >>> KVM: x86: fix maintaining of kvm_clock stability on guest CPU hotplug >>> >>> arch/x86/kvm/x86.c | 59 ++++++++++++++++++------------------------------------ >>> 1 file changed, 20 insertions(+), 39 deletions(-) >>>