From bd00cd52d5be655a2f217e2ed74b91a71cb2b14f Mon Sep 17 00:00:00 2001 From: Tianyu Lan Date: Wed, 14 Aug 2019 20:32:16 +0800 Subject: clocksource/drivers/hyperv: Add Hyper-V specific sched clock function Hyper-V guests use the default native_sched_clock() in pv_ops.time.sched_clock on x86. But native_sched_clock() directly uses the raw TSC value, which can be discontinuous in a Hyper-V VM. Add the generic hv_setup_sched_clock() to set the sched clock function appropriately. On x86, this sets pv_ops.time.sched_clock to read the Hyper-V reference TSC value that is scaled and adjusted to be continuous. Also move the Hyper-V reference TSC initialization much earlier in the boot process so no discontinuity is observed when pv_ops.time.sched_clock calculates its offset. [ tglx: Folded build fix ] Signed-off-by: Tianyu Lan Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Link: https://lkml.kernel.org/r/20190814123216.32245-3-Tianyu.Lan@microsoft.com --- include/asm-generic/mshyperv.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/asm-generic') diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index 0becb7d9704d..18d8e2d8210f 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -167,6 +167,7 @@ void hyperv_report_panic(struct pt_regs *regs, long err); void hyperv_report_panic_msg(phys_addr_t pa, size_t size); bool hv_is_hyperv_initialized(void); void hyperv_cleanup(void); +void hv_setup_sched_clock(void *sched_clock); #else /* CONFIG_HYPERV */ static inline bool hv_is_hyperv_initialized(void) { return false; } static inline void hyperv_cleanup(void) {} -- cgit v1.2.3