Re: [RFC 2/7] change headers preparing for steal time

[Avi Kivity <avi@redhat.com>]

  On 08/26/2010 12:43 AM, Glauber Costa wrote:
> This guest/host common patch prepares infrastructure for
> the steal time implementation. Some constants are added,
> and a name change happens in pvclock vcpu structure.
>
> Signed-off-by: Glauber Costa<glommer@redhat.com>
> ---
>   arch/x86/include/asm/kvm_para.h    |    1 +
>   arch/x86/include/asm/pvclock-abi.h |    4 +++-
>   2 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
> index 05eba5e..1759c81 100644
> --- a/arch/x86/include/asm/kvm_para.h
> +++ b/arch/x86/include/asm/kvm_para.h
> @@ -25,6 +25,7 @@
>    * in pvclock structure. If no bits are set, all flags are ignored.
>    */
>   #define KVM_FEATURE_CLOCKSOURCE_STABLE_BIT	24
> +#define KVM_FEATURE_CLOCKSOURCE_STEAL_BIT 	25
>
>   #define MSR_KVM_WALL_CLOCK  0x11
>   #define MSR_KVM_SYSTEM_TIME 0x12
> diff --git a/arch/x86/include/asm/pvclock-abi.h b/arch/x86/include/asm/pvclock-abi.h
> index 35f2d19..417061b 100644
> --- a/arch/x86/include/asm/pvclock-abi.h
> +++ b/arch/x86/include/asm/pvclock-abi.h
> @@ -24,7 +24,7 @@
>
>   struct pvclock_vcpu_time_info {
>   	u32   version;
> -	u32   pad0;
> +	u32   steal_time;
>   	u64   tsc_timestamp;
>   	u64   system_time;
>   	u32   tsc_to_system_mul;
> @@ -40,5 +40,7 @@ struct pvclock_wall_clock {
>   } __attribute__((__packed__));
>
>   #define PVCLOCK_TSC_STABLE_BIT	(1<<  0)
> +#define PVCLOCK_STEAL_BIT   (2<<  0)
> +
>   #endif /* __ASSEMBLY__ */
>   #endif /* _ASM_X86_PVCLOCK_ABI_H */

We could extend pvclock to 64 bytes (unfortunately we didn't reserve 
bits 0-5 like we did with others) and use an nsec field.

We can declare bit 1 to be a 'the address is 64 byte aligned and bits 
2-5 are now feature bits', or we can add a new msr.  Pretty complicated 
but it's good to have everything using the same units.

-- 
error compiling committee.c: too many arguments to function