Re: [PATCH 3/5] ppc/spapr: Add FWNMI machine check delivery warnings

[Nicholas Piggin]

Greg Kurz's on March 17, 2020 10:20 pm:
> On Tue, 17 Mar 2020 15:02:13 +1000
> Nicholas Piggin  wrote:
> 
>> Add some messages which explain problems and guest misbehaviour that
>> may be difficult to diagnose in rare cases of machine checks.
>> 
>> Signed-off-by: Nicholas Piggin 
>> ---
>>  hw/ppc/spapr_events.c | 4 
>>  hw/ppc/spapr_rtas.c   | 4 
>>  2 files changed, 8 insertions(+)
>> 
>> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
>> index 05337f0671..d35151eeb0 100644
>> --- a/hw/ppc/spapr_events.c
>> +++ b/hw/ppc/spapr_events.c
>> @@ -807,6 +807,8 @@ static void spapr_mce_dispatch_elog(PowerPCCPU *cpu, 
>> bool recovered)
>>  /* get rtas addr from fdt */
>>  rtas_addr = spapr_get_rtas_addr();
>>  if (!rtas_addr) {
>> +warn_report("FWNMI: Unable to deliver machine check to guest: "
>> +"rtas_addr not found.");
> 
> Why a warning and not an error ?
> 
> Also maybe change the string to fit on one line ?

Not sure, I guess it should be.

Thanks,
Nick

Re: [PATCH 3/5] ppc/spapr: Add FWNMI machine check delivery warnings

[Greg Kurz]

On Tue, 17 Mar 2020 15:02:13 +1000
Nicholas Piggin  wrote:

> Add some messages which explain problems and guest misbehaviour that
> may be difficult to diagnose in rare cases of machine checks.
> 
> Signed-off-by: Nicholas Piggin 
> ---
>  hw/ppc/spapr_events.c | 4 
>  hw/ppc/spapr_rtas.c   | 4 
>  2 files changed, 8 insertions(+)
> 
> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
> index 05337f0671..d35151eeb0 100644
> --- a/hw/ppc/spapr_events.c
> +++ b/hw/ppc/spapr_events.c
> @@ -807,6 +807,8 @@ static void spapr_mce_dispatch_elog(PowerPCCPU *cpu, bool 
> recovered)
>  /* get rtas addr from fdt */
>  rtas_addr = spapr_get_rtas_addr();
>  if (!rtas_addr) {
> +warn_report("FWNMI: Unable to deliver machine check to guest: "
> +"rtas_addr not found.");

Why a warning and not an error ?

Also maybe change the string to fit on one line ?

>  qemu_system_guest_panicked(NULL);
>  g_free(ext_elog);
>  return;
> @@ -848,6 +850,8 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
>   * that CPU called "ibm,nmi-interlock")
>   */
>  if (spapr->fwnmi_machine_check_interlock == cpu->vcpu_id) {
> +warn_report("FWNMI: Unable to deliver machine check to guest: "
> +"nested machine check.");

Ditto.

>  qemu_system_guest_panicked(NULL);
>  return;
>  }
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index 29abe66d01..12cd09701c 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -462,6 +462,10 @@ static void rtas_ibm_nmi_interlock(PowerPCCPU *cpu,
>  }
>  
>  if (spapr->fwnmi_machine_check_addr == -1) {
> +qemu_log_mask(LOG_GUEST_ERROR,
> +  "FWNMI: ibm,nmi-interlock RTAS called with FWNMI not "
> +   "registered.\n");

whitespace damage here   ^ best fixed by making the message a one liner.

> +
>  /* NMI register not called */
>  rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
>  return;

[PATCH 3/5] ppc/spapr: Add FWNMI machine check delivery warnings

[Nicholas Piggin]

Add some messages which explain problems and guest misbehaviour that
may be difficult to diagnose in rare cases of machine checks.

Signed-off-by: Nicholas Piggin 
---
 hw/ppc/spapr_events.c | 4 
 hw/ppc/spapr_rtas.c   | 4 
 2 files changed, 8 insertions(+)

diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index 05337f0671..d35151eeb0 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -807,6 +807,8 @@ static void spapr_mce_dispatch_elog(PowerPCCPU *cpu, bool 
recovered)
 /* get rtas addr from fdt */
 rtas_addr = spapr_get_rtas_addr();
 if (!rtas_addr) {
+warn_report("FWNMI: Unable to deliver machine check to guest: "
+"rtas_addr not found.");
 qemu_system_guest_panicked(NULL);
 g_free(ext_elog);
 return;
@@ -848,6 +850,8 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
  * that CPU called "ibm,nmi-interlock")
  */
 if (spapr->fwnmi_machine_check_interlock == cpu->vcpu_id) {
+warn_report("FWNMI: Unable to deliver machine check to guest: "
+"nested machine check.");
 qemu_system_guest_panicked(NULL);
 return;
 }
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 29abe66d01..12cd09701c 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -462,6 +462,10 @@ static void rtas_ibm_nmi_interlock(PowerPCCPU *cpu,
 }
 
 if (spapr->fwnmi_machine_check_addr == -1) {
+qemu_log_mask(LOG_GUEST_ERROR,
+  "FWNMI: ibm,nmi-interlock RTAS called with FWNMI not "
+   "registered.\n");
+
 /* NMI register not called */
 rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 return;
-- 
2.23.0