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 | |