Re: [PATCH 6.6.y] x86/hyperv: Fix hv tsc page based sched_clock for hibernation

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Found matching upstream commit: bcc80dec91ee745b3d66f3e48f0ec2efdea97149


Status in newer kernel trees:
6.12.y | Present (different SHA1: bacd0498dea0)
6.6.y | Present (different SHA1: 4c8d45af23c2)

Note: The patch differs from the upstream commit:
---
1:  bcc80dec91ee ! 1:  cc5a1702c099 x86/hyperv: Fix hv tsc page based sched_clock for hibernation
    @@ Commit message
         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>
    +    (cherry picked from commit bcc80dec91ee745b3d66f3e48f0ec2efdea97149)
    +    Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
     
      ## arch/x86/kernel/cpu/mshyperv.c ##
     @@ arch/x86/kernel/cpu/mshyperv.c: static void hv_machine_crash_shutdown(struct pt_regs *regs)
      	hyperv_cleanup();
      }
    - #endif /* CONFIG_CRASH_DUMP */
    + #endif /* CONFIG_KEXEC_CORE */
     +
     +static u64 hv_ref_counter_at_suspend;
     +static void (*old_save_sched_clock_state)(void);
    @@ drivers/clocksource/hyperv_timer.c
      /*
       * If false, we're using the old mechanism for stimer0 interrupts
     @@ drivers/clocksource/hyperv_timer.c: static void resume_hv_clock_tsc(struct clocksource *arg)
    - 	hv_set_msr(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
    + 	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
      }
      
     +/*
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |