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| author | Tianyu Lan <Tianyu.Lan@microsoft.com> | 2019-08-14 20:32:16 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-08-23 16:59:54 +0200 |
| commit | bd00cd52d5be655a2f217e2ed74b91a71cb2b14f (patch) | |
| tree | 90b8fe8d71a849f6066d1c2ba7500dba0fca9819 /arch/x86/kernel/cpu/mshyperv.c | |
| parent | adb87ff4f96c9700718e09c97a804124d5cd61ff (diff) | |
| download | linux-bd00cd52d5be655a2f217e2ed74b91a71cb2b14f.tar.bz2 | |
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 <Tianyu.Lan@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lkml.kernel.org/r/20190814123216.32245-3-Tianyu.Lan@microsoft.com
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 062f77279ce3..53afd33990eb 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -29,6 +29,7 @@ #include <asm/timer.h> #include <asm/reboot.h> #include <asm/nmi.h> +#include <clocksource/hyperv_timer.h> struct ms_hyperv_info ms_hyperv; EXPORT_SYMBOL_GPL(ms_hyperv); @@ -338,9 +339,16 @@ static void __init ms_hyperv_init_platform(void) x2apic_phys = 1; # endif + /* Register Hyper-V specific clocksource */ + hv_init_clocksource(); #endif } +void hv_setup_sched_clock(void *sched_clock) +{ + pv_ops.time.sched_clock = sched_clock; +} + const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = { .name = "Microsoft Hyper-V", .detect = ms_hyperv_platform, |