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| -rw-r--r-- | arch/ia64/include/asm/pvclock-abi.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/ia64/include/asm/pvclock-abi.h b/arch/ia64/include/asm/pvclock-abi.h new file mode 100644 index 00000000000..44ef9ef8f5b --- /dev/null +++ b/arch/ia64/include/asm/pvclock-abi.h @@ -0,0 +1,48 @@ +/* + * same structure to x86's + * Hopefully asm-x86/pvclock-abi.h would be moved to somewhere more generic. + * For now, define same duplicated definitions. + */ + +#ifndef _ASM_IA64__PVCLOCK_ABI_H +#define _ASM_IA64__PVCLOCK_ABI_H +#ifndef __ASSEMBLY__ + +/* + * 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. There is one per virtual cpu. + * + * 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 { + u32 version; + u32 pad0; + u64 tsc_timestamp; + u64 system_time; + u32 tsc_to_system_mul; + s8 tsc_shift; + u8 pad[3]; +} __attribute__((__packed__)); /* 32 bytes */ + +struct pvclock_wall_clock { + u32 version; + u32 sec; + u32 nsec; +} __attribute__((__packed__)); + +#endif /* __ASSEMBLY__ */ +#endif /* _ASM_IA64__PVCLOCK_ABI_H */ |