Re: include files for kvmclock

[Jeremy Fitzhardinge <jeremy@goop.org>]

Glauber de Oliveira Costa wrote:
> This patch introduces the include files for kvm clock.
> They'll be needed for both guest and host part.
>
> Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
> ---
>  include/asm-x86/kvm_para.h |   23 +++++++++++++++++++++++
>  include/linux/kvm.h        |    1 +
>  include/linux/kvm_para.h   |   20 ++++++++++++++++++++
>  3 files changed, 44 insertions(+), 0 deletions(-)
>
> diff --git a/include/asm-x86/kvm_para.h b/include/asm-x86/kvm_para.h
> index c6f3fd8..af9fb75 100644
> --- a/include/asm-x86/kvm_para.h
> +++ b/include/asm-x86/kvm_para.h
> @@ -10,15 +10,38 @@
>   * paravirtualization, the appropriate feature bit should be checked.
>   */
>  #define KVM_CPUID_FEATURES	0x40000001
> +#define KVM_FEATURE_CLOCKEVENTS 0
> +#define KVM_FEATURE_CLOCKSOURCE 1
> +
>  
>  #ifdef __KERNEL__
>  #include <asm/processor.h>
> +extern void kvmclock_init(void);
> +
> +union kvm_hv_clock {
>   

Why two copies of this structure?

> +	struct {
> +		u64 tsc_mult;
> +		u64 now_ns;
> +		/* That's the wall clock, not the water closet */
> +		u64 wc_sec;
> +		u64 wc_nsec;
> +		u64 last_tsc;
> +		/* At first, we could use the tsc value as a marker, but Jeremy
> +		 * well noted that it will cause us locking problems in 32-bit
> +		 * sys, so we have a special version field */
> +		u32 version;
> +	};
> +	char page_align[PAGE_SIZE];
> +};
> +
>   

[...]

> +
> +union kvm_hv_clock {
> +	struct {
> +		u64 tsc_mult;
> +		u64 now_ns;
> +		/* That's the wall clock, not the water closet */
> +		u64 wc_sec;
> +		u64 wc_nsec;
> +		u64 last_tsc;
> +		/* At first, we could use the tsc value as a marker, but Jeremy
> +		 * well noted that it will cause us locking problems in 32-bit
> +		 * sys, so we have a special version field */
> +		u32 version;
> +	};
> +	char page_align[PAGE_SIZE];
> +};
> +
>  /*
>   * hypercalls use architecture specific
>   */
>