On Fri, Aug 06 2021 at 19:07, Hikaru Nishida wrote:
> This patch implements virtual suspend time injection support for kvm
git grep 'This patch' Documentation/process/
> hosts.
>
> If this functionality is enabled and the guest requests it, the host
> will stop all the clocks observed by the guest during the host's
> suspension and report the duration of suspend to the guest through
> struct kvm_host_suspend_time to give a chance to adjust CLOCK_BOOTTIME
> to the guest. This mechanism can be used to align the guest's clock
> behavior to the hosts' ones.
>
> Signed-off-by: Hikaru Nishida <hikalium@xxxxxxxxxxxx>
> ---
>
> arch/x86/include/asm/kvm_host.h | 5 ++
> arch/x86/kvm/Kconfig | 13 ++++
> arch/x86/kvm/cpuid.c | 4 ++
> arch/x86/kvm/x86.c | 109 +++++++++++++++++++++++++++++++-
> include/linux/kvm_host.h | 8 +++
> kernel/time/timekeeping.c | 3 +
Please split this into adding the infrastructure and then implementing
the x86 side of it.
>
> +#ifdef CONFIG_KVM_VIRT_SUSPEND_TIMING
> +void kvm_arch_timekeeping_inject_sleeptime(const struct timespec64 *delta);
+#else
+static inline void kvm_arch_timekeeping_inject_sleeptime(const struct timespec64 *delta){}
> +#endif /* CONFIG_KVM_VIRT_SUSPEND_TIMING */
> +
> #endif
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index 233ceb6cce1f..3ac3fb479981 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -1797,6 +1797,9 @@ void timekeeping_resume(void)
> if (inject_sleeptime) {
> suspend_timing_needed = false;
> __timekeeping_inject_sleeptime(tk, &ts_delta);
> +#ifdef CONFIG_KVM_VIRT_SUSPEND_TIMING
> + kvm_arch_timekeeping_inject_sleeptime(&ts_delta);
> +#endif
which get's rid of these ugly ifdefs.
Also this is the wrong place because sleep time can be injected from
other places as well. This should be in __timekeeping_inject_sleeptime()
if at all.
Thanks,
tglx
