Root partitions running on MSHV currently attempt ACPI power-off, which MSHV intercepts and triggers a Machine Check Exception (MCE), leading to a kernel panic.
Root partitions panic with a trace similar to: [ 81.306348] reboot: Power down [ 81.314709] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0060001 [ 81.314711] mce: [Hardware Error]: TSC 3b8cb60a66 PPIN 11d98332458e4ea9 [ 81.314713] mce: [Hardware Error]: PROCESSOR 0:606a6 TIME 1759339405 SOCKET 0 APIC 0 microcode ffffffff [ 81.314715] mce: [Hardware Error]: Run the above through 'mcelog --ascii' [ 81.314716] mce: [Hardware Error]: Machine check: Processor context corrupt [ 81.314717] Kernel panic - not syncing: Fatal machine check To avoid this, configure the sleep state in the hypervisor and invoke the HVCALL_ENTER_SLEEP_STATE hypercall as the final step in the shutdown sequence. This ensures a clean and safe shutdown of the root partition. Signed-off-by: Praveen K Paladugu <[email protected]> Co-developed-by: Anatol Belski <[email protected]> Signed-off-by: Anatol Belski <[email protected]> Reviewed-by: Easwar Hariharan <[email protected]> Acked-by: Stanislav Kinsburskii <[email protected]> --- arch/x86/include/asm/mshyperv.h | 1 + arch/x86/kernel/cpu/mshyperv.c | 2 ++ drivers/hv/mshv_common.c | 21 +++++++++++++++++++++ 3 files changed, 24 insertions(+) diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 62a89debfbce..eef4c3a5ba28 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -178,6 +178,7 @@ int hyperv_fill_flush_guest_mapping_list( struct hv_guest_mapping_flush_list *flush, u64 start_gfn, u64 end_gfn); void hv_sleep_notifiers_register(void); +void hv_machine_power_off(void); #ifdef CONFIG_X86_64 void hv_apic_init(void); diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index fac9953a72ef..579fb2c64cfd 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -621,6 +621,8 @@ static void __init ms_hyperv_init_platform(void) #endif #if IS_ENABLED(CONFIG_HYPERV) + if (hv_root_partition()) + machine_ops.power_off = hv_machine_power_off; #if defined(CONFIG_KEXEC_CORE) machine_ops.shutdown = hv_machine_shutdown; #endif diff --git a/drivers/hv/mshv_common.c b/drivers/hv/mshv_common.c index ee733ba1575e..58027b23c206 100644 --- a/drivers/hv/mshv_common.c +++ b/drivers/hv/mshv_common.c @@ -216,3 +216,24 @@ void hv_sleep_notifiers_register(void) pr_err("%s: cannot register reboot notifier %d\n", __func__, ret); } + +/* + * Power off the machine by entering S5 sleep state via Hyper-V hypercall. + * This call does not return if successful. + */ +void hv_machine_power_off(void) +{ + unsigned long flags; + struct hv_input_enter_sleep_state *in; + + local_irq_save(flags); + in = *this_cpu_ptr(hyperv_pcpu_input_arg); + in->sleep_state = HV_SLEEP_STATE_S5; + + (void)hv_do_hypercall(HVCALL_ENTER_SLEEP_STATE, in, NULL); + local_irq_restore(flags); + + /* should never reach here */ + BUG(); + +} -- 2.51.0
