arch/ia64/include/asm/pvclock-abi.h

   1 /*
   2  * same structure to x86's
   3  * Hopefully asm-x86/pvclock-abi.h would be moved to somewhere more generic.
   4  * For now, define same duplicated definitions.
   5  */
   6
   7 #ifndef _ASM_IA64__PVCLOCK_ABI_H
   8 #define _ASM_IA64__PVCLOCK_ABI_H
   9 #ifndef __ASSEMBLY__
  10
  11 /*
  12  * These structs MUST NOT be changed.
  13  * They are the ABI between hypervisor and guest OS.
  14  * KVM is using this.
  15  *
  16  * pvclock_vcpu_time_info holds the system time and the tsc timestamp
  17  * of the last update. So the guest can use the tsc delta to get a
  18  * more precise system time.  There is one per virtual cpu.
  19  *
  20  * pvclock_wall_clock references the point in time when the system
  21  * time was zero (usually boot time), thus the guest calculates the
  22  * current wall clock by adding the system time.
  23  *
  24  * Protocol for the "version" fields is: hypervisor raises it (making
  25  * it uneven) before it starts updating the fields and raises it again
  26  * (making it even) when it is done.  Thus the guest can make sure the
  27  * time values it got are consistent by checking the version before
  28  * and after reading them.
  29  */
  30
  31 struct pvclock_vcpu_time_info {
  32         u32   version;
  33         u32   pad0;
  34         u64   tsc_timestamp;
  35         u64   system_time;
  36         u32   tsc_to_system_mul;
  37         s8    tsc_shift;
  38         u8    pad[3];
  39 } __attribute__((__packed__)); /* 32 bytes */
  40
  41 struct pvclock_wall_clock {
  42         u32   version;
  43         u32   sec;
  44         u32   nsec;
  45 } __attribute__((__packed__));
  46
  47 #endif /* __ASSEMBLY__ */
  48 #endif /* _ASM_IA64__PVCLOCK_ABI_H */