Initialize tsc earlier by initializing the KVM clock at the same point in boot as other paravirtualized clocks. Here is how this work benefits time stamp output: 1. Current: https://paste.ubuntu.com/26133428 time keeping starts from line 873, and precise tsc time starts only from line 916. 2. Early boot time stamps [https://lkml.org/lkml/2017/11/15/925] without this patch: https://paste.ubuntu.com/26133441 precise time keeping starts from line 444. 3. This patch plus the early boot time stamps patch series: https://paste.ubuntu.com/26133523 time keeping starts from line 68. Pavel Tatashin (1): kvm/x86: make kvm to determin tsc frequency earlier arch/x86/include/asm/kvm_para.h | 2 +- arch/x86/kernel/kvm.c | 2 ++ arch/x86/kernel/kvmclock.c | 67 ++++++++++++++++++++++++++++------------- arch/x86/kernel/setup.c | 6 +--- 4 files changed, 50 insertions(+), 27 deletions(-) -- 2.15.1
