Gerd Hoffmann wrote:
> +/*
> + * These structs MUST NOT be changed.
> + * They are the ABI between hypervisor and guest OS.
> + * Both Xen and KVM are using this.
> + *
> + * pvclock_vcpu_time_info holds the system time and the tsc timestamp
> + * of the last update. So the guest can use the tsc delta to get a
> + * more precise system time.
>
You should note that these are per-cpu parameters.
> + *
> + * pvclock_wall_clock references the point in time when the system
> + * time was zero (usually boot time), thus the guest calculates the
> + * current wall clock by adding the system time.
> + *
> + * Protocol for the "version" fields is: hypervisor raises it (making
> + * it uneven) before it starts updating the fields and raises it again
> + * (making it even) when it is done. Thus the guest can make sure the
> + * time values it got are consistent by checking the version before
> + * and after reading them.
> + */
> +
> +struct pvclock_vcpu_time_info {
> + uint32_t version;
>
Use the standard u32/u64 I think (or the __u32 forms, maybe).
> + uint32_t pad0;
> + uint64_t tsc_timestamp;
> + uint64_t system_time;
> + uint32_t tsc_to_system_mul;
> + int8_t tsc_shift;
> + int8_t pad[3];
> +} __attribute__((__packed__)); /* 32 bytes */
> +
> +struct pvclock_wall_clock {
> + uint32_t version;
> + uint32_t sec;
> + uint32_t nsec;
> +} __attribute__((__packed__));
> +
> +#endif /* __ASSEMBLY__ */
> +#endif /* _ASM_X86_PVCLOCK_ABI_H_ */
> diff --git a/include/asm-x86/pvclock.h b/include/asm-x86/pvclock.h
> new file mode 100644
> index 0000000..85b1bba
> --- /dev/null
> +++ b/include/asm-x86/pvclock.h
> @@ -0,0 +1,13 @@
> +#ifndef _ASM_X86_PVCLOCK_H_
> +#define _ASM_X86_PVCLOCK_H_
> +
> +#include <linux/clocksource.h>
> +#include <asm/pvclock-abi.h>
> +
> +/* some helper functions for xen and kvm pv clock sources */
> +cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
> +void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
> + struct pvclock_vcpu_time_info *vcpu,
> + struct timespec *ts);
> +
> +#endif /* _ASM_X86_PVCLOCK_H_ */
>
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