Naman Jain bcc80dec91 x86/hyperv: Fix hv tsc page based sched_clock for hibernation ... read_hv_sched_clock_tsc() assumes that the Hyper-V clock counter is bigger than the variable hv_sched_clock_offset, which is cached during early boot, but depending on the timing this assumption may be false when a hibernated VM starts again (the clock counter starts from 0 again) and is resuming back (Note: hv_init_tsc_clocksource() is not called during hibernation/resume); consequently, read_hv_sched_clock_tsc() may return a negative integer (which is interpreted as a huge positive integer since the return type is u64) and new kernel messages are prefixed with huge timestamps before read_hv_sched_clock_tsc() grows big enough (which typically takes several seconds). Fix the issue by saving the Hyper-V clock counter just before the suspend, and using it to correct the hv_sched_clock_offset in resume. This makes hv tsc page based sched_clock continuous and ensures that post resume, it starts from where it left off during suspend. Override x86_platform.save_sched_clock_state and x86_platform.restore_sched_clock_state routines to correct this as soon as possible. Note: if Invariant TSC is available, the issue doesn't happen because 1) we don't register read_hv_sched_clock_tsc() for sched clock: See commit e5313f1c54 ("clocksource/drivers/hyper-v: Rework clocksource and sched clock setup"); 2) the common x86 code adjusts TSC similarly: see __restore_processor_state() -> tsc_verify_tsc_adjust(true) and x86_platform.restore_sched_clock_state(). Cc: stable@vger.kernel.org Fixes: 1349401ff1 ("clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation") Co-developed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Naman Jain <namjain@linux.microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20240917053917.76787-1-namjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20240917053917.76787-1-namjain@linux.microsoft.com>		2024-12-09 18:42:42 +00:00
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acpi_pm.c
arc_timer.c
arm_arch_timer.c
arm_global_timer.c
armv7m_systick.c
asm9260_timer.c
bcm2835_timer.c
bcm_kona_timer.c
clksrc_st_lpc.c
clksrc-dbx500-prcmu.c
clps711x-timer.c
dummy_timer.c
dw_apb_timer_of.c
dw_apb_timer.c
em_sti.c
exynos_mct.c
hyperv_timer.c
i8253.c
ingenic-ost.c
ingenic-sysost.c
ingenic-timer.c
jcore-pit.c
Kconfig
Makefile
mips-gic-timer.c
mmio.c
mps2-timer.c
mxs_timer.c
nomadik-mtu.c
numachip.c
renesas-ostm.c
samsung_pwm_timer.c
scx200_hrt.c
sh_cmt.c
sh_mtu2.c
sh_tmu.c
timer-armada-370-xp.c
timer-atmel-pit.c
timer-atmel-st.c
timer-atmel-tcb.c
timer-cadence-ttc.c
timer-clint.c
timer-cs5535.c
timer-davinci.c
timer-digicolor.c
timer-ep93xx.c
timer-fsl-ftm.c
timer-fttmr010.c
timer-goldfish.c
timer-gx6605s.c
timer-gxp.c
timer-imx-gpt.c
timer-imx-sysctr.c
timer-imx-tpm.c
timer-integrator-ap.c
timer-ixp4xx.c
timer-keystone.c
timer-loongson1-pwm.c
timer-lpc32xx.c
timer-mediatek-cpux.c
timer-mediatek.c
timer-meson6.c
timer-microchip-pit64b.c
timer-milbeaut.c
timer-mp-csky.c
timer-msc313e.c
timer-npcm7xx.c
timer-of.c
timer-of.h
timer-orion.c
timer-owl.c
timer-pistachio.c
timer-probe.c
timer-pxa.c
timer-qcom.c
timer-ralink.c
timer-rda.c
timer-riscv.c
timer-rockchip.c
timer-rtl-otto.c
timer-sp804.c
timer-sp.h
timer-sprd.c
timer-stm32-lp.c
timer-stm32.c
timer-sun4i.c
timer-sun5i.c
timer-tegra186.c
timer-tegra.c
timer-ti-32k.c
timer-ti-dm-systimer.c
timer-ti-dm.c
timer-versatile.c
timer-vf-pit.c
timer-vt8500.c
timer-zevio.c