Re: [PATCH v7 1/8] machine: Use error handling when CPU type is checked

[Gavin Shan <gshan@redhat.com>]

Hi Phil,

On 11/28/23 20:43, Philippe Mathieu-Daudé wrote:
> On 27/11/23 00:12, Gavin Shan wrote:
>> QEMU will be terminated if the specified CPU type isn't supported
>> in machine_run_board_init(). The list of supported CPU type names
>> is tracked by mc->valid_cpu_types.
>>
>> The error handling can be used to propagate error messages, to be
>> consistent how the errors are handled for other situations in the
>> same function.
>>
>> No functional change intended.
>>
>> Suggested-by: Igor Mammedov <imammedo@redhat.com>
>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>> ---
>> v7: Add 'return' after error_propagate() to avoid calling into
>>      mc->init() in the failing case                        (Marcin)
>> ---
>>   hw/core/machine.c | 15 +++++++++------
>>   1 file changed, 9 insertions(+), 6 deletions(-)
>>
>> diff --git a/hw/core/machine.c b/hw/core/machine.c
>> index 0c17398141..b3ef325936 100644
>> --- a/hw/core/machine.c
>> +++ b/hw/core/machine.c
>> @@ -1394,6 +1394,7 @@ void machine_run_board_init(MachineState *machine, const char *mem_path, Error *
>>       MachineClass *machine_class = MACHINE_GET_CLASS(machine);
>>       ObjectClass *oc = object_class_by_name(machine->cpu_type);
>>       CPUClass *cc;
>> +    Error *local_err = NULL;
> 
> IIUC the big comment in "include/qapi/error.h", since commit ae7c80a7bd
> ("error: New macro ERRP_GUARD()") we want to use the new macro instead.
> 

Yeah, there already has a ERRP_GUARD() in machine_run_board_init(). After
rechecking the implementation of ERRP_GUARD(), I found @local_err needs to
be dropped and use @errp below.


>>       /* This checkpoint is required by replay to separate prior clock
>>          reading from the other reads, because timer polling functions query
>> @@ -1466,15 +1467,17 @@ void machine_run_board_init(MachineState *machine, const char *mem_path, Error *
>>           if (!machine_class->valid_cpu_types[i]) {
>>               /* The user specified CPU is not valid */
>> -            error_report("Invalid CPU type: %s", machine->cpu_type);
>> -            error_printf("The valid types are: %s",
>> -                         machine_class->valid_cpu_types[0]);
>> +            error_setg(&local_err, "Invalid CPU type: %s", machine->cpu_type);
>> +            error_append_hint(&local_err, "The valid types are: %s",
>> +                              machine_class->valid_cpu_types[0]);
>>               for (i = 1; machine_class->valid_cpu_types[i]; i++) {
>> -                error_printf(", %s", machine_class->valid_cpu_types[i]);
>> +                error_append_hint(&local_err, ", %s",
>> +                                  machine_class->valid_cpu_types[i]);
>>               }
>> -            error_printf("\n");
>> +            error_append_hint(&local_err, "\n");
>> -            exit(1);
>> +            error_propagate(errp, local_err);
>> +            return;
>>           }
>>       }

@local_err needs to be replaced with @errp in this chunk of code, as mentioned
above.

Thanks,
Gavin