1 #ifndef _ASM_X86_PVCLOCK_ABI_H 2 #define _ASM_X86_PVCLOCK_ABI_H 3 #ifndef __ASSEMBLY__ 4 5 /* 6 * These structs MUST NOT be changed. 7 * They are the ABI between hypervisor and guest OS. 8 * Both Xen and KVM are using this. 9 * 10 * pvclock_vcpu_time_info holds the system time and the tsc timestamp 11 * of the last update. So the guest can use the tsc delta to get a 12 * more precise system time. There is one per virtual cpu. 13 * 14 * pvclock_wall_clock references the point in time when the system 15 * time was zero (usually boot time), thus the guest calculates the 16 * current wall clock by adding the system time. 17 * 18 * Protocol for the "version" fields is: hypervisor raises it (making 19 * it uneven) before it starts updating the fields and raises it again 20 * (making it even) when it is done. Thus the guest can make sure the 21 * time values it got are consistent by checking the version before 22 * and after reading them. 23 */ 24 25 struct pvclock_vcpu_time_info { 26 u32 version; 27 u32 pad0; 28 u64 tsc_timestamp; 29 u64 system_time; 30 u32 tsc_to_system_mul; 31 s8 tsc_shift; 32 u8 flags; 33 u8 pad[2]; 34 } __attribute__((__packed__)); /* 32 bytes */ 35 36 struct pvclock_wall_clock { 37 u32 version; 38 u32 sec; 39 u32 nsec; 40 } __attribute__((__packed__)); 41 42 #define PVCLOCK_TSC_STABLE_BIT (1 << 0) 43 #define PVCLOCK_GUEST_STOPPED (1 << 1) 44 /* PVCLOCK_COUNTS_FROM_ZERO broke ABI and can't be used anymore. */ 45 #define PVCLOCK_COUNTS_FROM_ZERO (1 << 2) 46 #endif /* __ASSEMBLY__ */ 47 #endif /* _ASM_X86_PVCLOCK_ABI_H */ 48