blob: 6167fd7981886228dc075f58901380be63ed87a7 (
plain) (
tree)
|
|
#ifndef _ASM_X86_PVCLOCK_ABI_H
#define _ASM_X86_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 flags;
u8 pad[2];
} __attribute__((__packed__)); /* 32 bytes */
struct pvclock_wall_clock {
u32 version;
u32 sec;
u32 nsec;
} __attribute__((__packed__));
#define PVCLOCK_TSC_STABLE_BIT (1 << 0)
#define PVCLOCK_GUEST_STOPPED (1 << 1)
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_PVCLOCK_ABI_H */
|
