linux/arch/ia64/include/asm/pvclock-abi.h
<<
>>
Prefs
   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 * Both Xen and KVM are 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
  31struct 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
  41struct 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 */
  49