Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[can-eth-gw-linux.git] / arch / x86 / include / asm / pvclock.h

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index c59cc97fe6c1478225863d0d814bece995652f5a..109a9dd5d454f197414e2449617cf9cb73ab1220 100644 (file)
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -6,6 +6,7 @@
 
 /* some helper functions for xen and kvm pv clock sources */
 cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
+u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
 void pvclock_set_flags(u8 flags);
 unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
 void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
@@ -56,4 +57,50 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
        return product;
 }
 
+static __always_inline
+u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
+{
+       u64 delta = __native_read_tsc() - src->tsc_timestamp;
+       return pvclock_scale_delta(delta, src->tsc_to_system_mul,
+                                  src->tsc_shift);
+}
+
+static __always_inline
+unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
+                              cycle_t *cycles, u8 *flags)
+{
+       unsigned version;
+       cycle_t ret, offset;
+       u8 ret_flags;
+
+       version = src->version;
+       /* Note: emulated platforms which do not advertise SSE2 support
+        * result in kvmclock not using the necessary RDTSC barriers.
+        * Without barriers, it is possible that RDTSC instruction reads from
+        * the time stamp counter outside rdtsc_barrier protected section
+        * below, resulting in violation of monotonicity.
+        */
+       rdtsc_barrier();
+       offset = pvclock_get_nsec_offset(src);
+       ret = src->system_time + offset;
+       ret_flags = src->flags;
+       rdtsc_barrier();
+
+       *cycles = ret;
+       *flags = ret_flags;
+       return version;
+}
+
+struct pvclock_vsyscall_time_info {
+       struct pvclock_vcpu_time_info pvti;
+       u32 migrate_count;
+} __attribute__((__aligned__(SMP_CACHE_BYTES)));
+
+#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
+#define PVCLOCK_VSYSCALL_NR_PAGES (((NR_CPUS-1)/(PAGE_SIZE/PVTI_SIZE))+1)
+
+int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,
+                                int size);
+struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu);
+
 #endif /* _ASM_X86_PVCLOCK_H */