On 09/08/2018 16:52, Marcelo Tosatti wrote:
> Commit 0bc48bea36d1 ("KVM: x86: update master clock before computing kvmclock_offset")
> switches the order of operations to avoid the conversion
>
> TSC (without frequency correction) ->
> system_timestamp (with frequency correction),
>
> which might cause a time jump.
>
> However, it leaves any other masterclock update unsafe, which includes,
> at the moment:
>
> * HV_X64_MSR_REFERENCE_TSC MSR write.
> * TSC writes.
> * Host suspend/resume.
>
> Avoid the time jump issue by using frequency uncorrected
> CLOCK_MONOTONIC_RAW clock.
>
> Its the guests time keeping software responsability
> to track and correct a reference clock such as UTC.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
What happens across migration?
Paolo
