From mboxrd@z Thu Jan 1 00:00:00 1970 From: Radim =?utf-8?B?S3LEjW3DocWZ?= Subject: Re: [PATCH 0/2] maintaining of kvm_clock stability on guest vCPU hotplug Date: Wed, 5 Apr 2017 16:23:44 +0200 Message-ID: <20170405142343.GE6369@potion> References: <1490279313-254442-1-git-send-email-dplotnikov@virtuozzo.com> <4c090183-b775-a5f6-a0f2-f8c85a6b1887@virtuozzo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: pbonzini@redhat.com, mtosatti@redhat.com, kvm@vger.kernel.org, rkagan@virtuozzo.com, den@virtuozzo.com To: Denis Plotnikov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37176 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932359AbdDEOXx (ORCPT ); Wed, 5 Apr 2017 10:23:53 -0400 Content-Disposition: inline In-Reply-To: <4c090183-b775-a5f6-a0f2-f8c85a6b1887@virtuozzo.com> Sender: kvm-owner@vger.kernel.org List-ID: 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(-) >> > > -- > Best, > Denis