1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_PVCLOCK_ABI_H 3 #define _ASM_X86_PVCLOCK_ABI_H 4 #ifndef __ASSEMBLY__ 5 6 /* 7 * These structs MUST NOT be changed. 8 * They are the ABI between hypervisor and guest OS. 9 * Both Xen and KVM are using this. 10 * 11 * pvclock_vcpu_time_info holds the system time and the tsc timestamp 12 * of the last update. So the guest can use the tsc delta to get a 13 * more precise system time. There is one per virtual cpu. 14 * 15 * pvclock_wall_clock references the point in time when the system 16 * time was zero (usually boot time), thus the guest calculates the 17 * current wall clock by adding the system time. 18 * 19 * Protocol for the "version" fields is: hypervisor raises it (making 20 * it uneven) before it starts updating the fields and raises it again 21 * (making it even) when it is done. Thus the guest can make sure the 22 * time values it got are consistent by checking the version before 23 * and after reading them. 24 */ 25 26 struct pvclock_vcpu_time_info { 27 u32 version; 28 u32 pad0; 29 u64 tsc_timestamp; 30 u64 system_time; 31 u32 tsc_to_system_mul; 32 s8 tsc_shift; 33 u8 flags; 34 u8 pad[2]; 35 } __attribute__((__packed__)); /* 32 bytes */ 36 37 struct pvclock_wall_clock { 38 u32 version; 39 u32 sec; 40 u32 nsec; 41 } __attribute__((__packed__)); 42 43 #define PVCLOCK_TSC_STABLE_BIT (1 << 0) 44 #define PVCLOCK_GUEST_STOPPED (1 << 1) 45 /* PVCLOCK_COUNTS_FROM_ZERO broke ABI and can't be used anymore. */ 46 #define PVCLOCK_COUNTS_FROM_ZERO (1 << 2) 47 #endif /* __ASSEMBLY__ */ 48 #endif /* _ASM_X86_PVCLOCK_ABI_H */ 49