From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denis Plotnikov Subject: [PATCH v3 0/6] make L2's kvm-clock stable, get rid of pvclock_gtod Date: Sat, 29 Jul 2017 15:35:05 +0300 Message-ID: <1501331711-12961-1-git-send-email-dplotnikov@virtuozzo.com> Cc: rkagan@virtuozzo.com, den@virtuozzo.com, svt-core@lists.sw.ru To: pbonzini@redhat.com, rkrcmar@redhat.com, kvm@vger.kernel.org Return-path: Received: from mailhub.sw.ru ([195.214.232.25]:14820 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753725AbdG2Mfz (ORCPT ); Sat, 29 Jul 2017 08:35:55 -0400 Sender: kvm-owner@vger.kernel.org List-ID: V3: Changing the timekeeper interface for clocksource reading looks like an overkill to achive the goal of getting cycles stamp for KVM. Instead extend the timekeeping interface and add functions which provide necessary data: read clocksource with cycles stamp, check whether the clock source is stable. Use those functions and improve existing timekeeper functionality to replace pvclock_gtod_copy scheme in masterclock data calculation. V2: The main goal is to make L2 kvm-clock be stable when it's running over L1 with stable kvm-clock. The patch series is for x86 architecture only. If the series is approved I'll do changes for other architectures but I don't have an ability to compile and check for every single on (help needed) The patch series do the following: * change timekeeper interface to get cycles stamp value from the timekeeper * get rid of pvclock copy in KVM by using the changed timekeeper interface: get time and cycles right from the timekeeper * make KVM recognize a stable kvm-clock as stable clocksource and use the KVM masterclock in this case, which means making L2 stable when running over stable L1 kvm-clock Denis Plotnikov (6): pvclock: add parameter to store cycles stamp to pvclock reading function KVM: x86: switch to masterclock update using timekeeper functionality timekeeper: add clocksource change notifier KVM: x86: remove not used pvclock_gtod_copy pvclock: add clocksource change notification on changing of tsc stable bit kvmclock: add the clocksource stability querying function arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/include/asm/pvclock.h | 2 +- arch/x86/kernel/kvmclock.c | 26 ++++- arch/x86/kernel/pvclock.c | 31 ++++- arch/x86/kernel/tsc.c | 6 + arch/x86/kvm/trace.h | 31 ++--- arch/x86/kvm/x86.c | 242 ++++++++-------------------------------- arch/x86/xen/time.c | 2 +- include/linux/clocksource.h | 3 + include/linux/cs_notifier.h | 17 +++ include/linux/timekeeping.h | 2 + kernel/time/timekeeping.c | 72 +++++++++++- 12 files changed, 209 insertions(+), 227 deletions(-) create mode 100644 include/linux/cs_notifier.h -- 2.7.4