Re: [PATCH v2] ppc/spapr: Set the effective address provided flag in mc error log.

[Nicholas Piggin]

Mahesh Salgaonkar's on March 18, 2020 5:34 pm:
> Per PAPR, it is expected to set effective address provided flag in
> sub_err_type member of mc extended error log (i.e
> rtas_event_log_v6_mc.sub_err_type). This somehow got missed in original
> fwnmi-mce patch series. The current code just updates the effective address
> but does not set the flag to indicate that it is available. Hence guest
> fails to extract effective address from mce rtas log. This patch fixes
> that.
> 
> Without this patch guest MCE logs fails print DAR value:
> 
> [   11.933608] Disabling lock debugging due to kernel taint
> [   11.933773] MCE: CPU0: machine check (Severe) Host TLB Multihit [Recovered]
> [   11.933979] MCE: CPU0: NIP: [c000000000090b34] 
> radix__flush_tlb_range_psize+0x194/0xf00
> [   11.934223] MCE: CPU0: Initiator CPU
> [   11.934341] MCE: CPU0: Unknown
> 
> After the change:
> 
> [   22.454149] Disabling lock debugging due to kernel taint
> [   22.454316] MCE: CPU0: machine check (Severe) Host TLB Multihit DAR: 
> deadbeefdeadbeef [Recovered]
> [   22.454605] MCE: CPU0: NIP: [c0000000003e5804] kmem_cache_alloc+0x84/0x330
> [   22.454820] MCE: CPU0: Initiator CPU
> [   22.454944] MCE: CPU0: Unknown

Thanks, I was wondering why my MCEs weren't printing a DAR!

Reviewed-by: Nicholas Piggin <address@hidden>

> 
> 
> Signed-off-by: Mahesh Salgaonkar <address@hidden>
> ---
> Change in v2:
> - Fixed coding style issues.
> ---
>  hw/ppc/spapr_events.c |   26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
> index 8b32b7eea5..cb6bfedc53 100644
> --- a/hw/ppc/spapr_events.c
> +++ b/hw/ppc/spapr_events.c
> @@ -243,6 +243,14 @@ struct rtas_event_log_v6_mc {
>  #define RTAS_LOG_V6_MC_TLB_PARITY                        1
>  #define RTAS_LOG_V6_MC_TLB_MULTIHIT                      2
>  #define RTAS_LOG_V6_MC_TLB_INDETERMINATE                 3
> +/*
> + * Per PAPR,
> + * For UE error type, set bit 1 of sub_err_type to indicate effective addr is
> + * provided. For other error types (SLB/ERAT/TLB), set bit 0 to indicate
> + * same.
> + */
> +#define RTAS_LOG_V6_MC_UE_EA_ADDR_PROVIDED               0x40
> +#define RTAS_LOG_V6_MC_EA_ADDR_PROVIDED                  0x80
>      uint8_t reserved_1[6];
>      uint64_t effective_address;
>      uint64_t logical_address;
> @@ -726,6 +734,22 @@ void 
> spapr_hotplug_req_remove_by_count_indexed(SpaprDrcType drc_type,
>                              RTAS_LOG_V6_HP_ACTION_REMOVE, drc_type, &drc_id);
>  }
>  
> +static void spapr_mc_set_ea_provided_flag(struct mc_extended_log *ext_elog)
> +{
> +    switch (ext_elog->mc.error_type) {
> +    case RTAS_LOG_V6_MC_TYPE_UE:
> +        ext_elog->mc.sub_err_type |= RTAS_LOG_V6_MC_UE_EA_ADDR_PROVIDED;
> +        break;
> +    case RTAS_LOG_V6_MC_TYPE_SLB:
> +    case RTAS_LOG_V6_MC_TYPE_ERAT:
> +    case RTAS_LOG_V6_MC_TYPE_TLB:
> +        ext_elog->mc.sub_err_type |= RTAS_LOG_V6_MC_EA_ADDR_PROVIDED;
> +        break;
> +    default:
> +        break;
> +    }
> +}
> +
>  static uint32_t spapr_mce_get_elog_type(PowerPCCPU *cpu, bool recovered,
>                                          struct mc_extended_log *ext_elog)
>  {
> @@ -751,6 +775,7 @@ static uint32_t spapr_mce_get_elog_type(PowerPCCPU *cpu, 
> bool recovered,
>              ext_elog->mc.sub_err_type = mc_derror_table[i].error_subtype;
>              if (mc_derror_table[i].dar_valid) {
>                  ext_elog->mc.effective_address = 
> cpu_to_be64(env->spr[SPR_DAR]);
> +                spapr_mc_set_ea_provided_flag(ext_elog);
>              }
>  
>              summary |= mc_derror_table[i].initiator
> @@ -769,6 +794,7 @@ static uint32_t spapr_mce_get_elog_type(PowerPCCPU *cpu, 
> bool recovered,
>              ext_elog->mc.sub_err_type = mc_ierror_table[i].error_subtype;
>              if (mc_ierror_table[i].nip_valid) {
>                  ext_elog->mc.effective_address = cpu_to_be64(env->nip);
> +                spapr_mc_set_ea_provided_flag(ext_elog);
>              }
>  
>              summary |= mc_ierror_table[i].initiator
> 
>