mirror_ubuntu-kernels/include
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
..
acpi common: switch back from remove_new() to remove() callback 2024-11-25 17:31:39 -08:00
asm-generic - Fix a case where posix timers with a thread-group-wide target would miss 2024-12-01 12:41:21 -08:00
clocksource x86/hyperv: Fix hv tsc page based sched_clock for hibernation 2024-12-09 18:42:42 +00:00
crypto This update includes the following changes: 2024-11-19 10:28:41 -08:00
cxl
drm Merge tag 'drm-misc-fixes-2024-12-05' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes 2024-12-06 08:40:47 +10:00
dt-bindings Char/Misc/IIO/Whatever driver subsystem updates for 6.13-rc1 2024-11-29 11:58:27 -08:00
keys
kunit module: Convert symbol namespace to string literal 2024-12-02 11:34:44 -08:00
kvm KVM: arm64: vgic: Kill VGIC_MAX_PRIVATE definition 2024-11-20 17:21:08 -08:00
linux - Handle the case where clocksources with small counter width can, in 2024-12-08 11:51:29 -08:00
math-emu
media
memory
misc
net Including fixes from can and netfilter. 2024-12-05 10:25:06 -08:00
pcmcia
ras
rdma
rv
scsi Random number generator updates for Linux 6.13-rc1. 2024-11-19 10:43:44 -08:00
soc The core framework gained a clk provider helper, a clk consumer helper, and 2024-11-22 17:02:25 -08:00
sound ALSA: hda/tas2781: Add speaker id check for ASUS projects 2024-11-26 08:54:08 +01:00
target
trace mm/damon: fix order of arguments in damos_before_apply tracepoint 2024-12-05 19:54:47 -08:00
uapi iommu/arm-smmu-v3: Improve uAPI comment for IOMMU_HW_INFO_TYPE_ARM_SMMUV3 2024-12-03 13:30:31 -04:00
ufs scsi: ufs: core: Add missing post notify for power mode change 2024-12-04 13:22:59 -05:00
vdso
video - Improved handling of LCD power states and interactions with the fbdev subsystem. 2024-11-22 16:29:57 -08:00
xen