Re: [PATCH 4/6] cpus: Improve error messages on memsave, pmemsave write error

[Markus Armbruster <armbru@redhat.com>]

Philippe Mathieu-Daudé <philmd@linaro.org> writes:

> On 13/5/24 16:17, Markus Armbruster wrote:
>> qmp_memsave() and qmp_pmemsave() report fwrite() error as
>>      An IO error has occurred
>> Improve this to
>>      writing memory to '<filename>' failed
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>   system/cpus.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>> diff --git a/system/cpus.c b/system/cpus.c
>> index 68d161d96b..f8fa78f33d 100644
>> --- a/system/cpus.c
>> +++ b/system/cpus.c
>> @@ -813,7 +813,8 @@ void qmp_memsave(int64_t addr, int64_t size, const char *filename,
>>               goto exit;
>>           }
>>           if (fwrite(buf, 1, l, f) != l) {
>> -            error_setg(errp, QERR_IO_ERROR);
>> +            error_setg(errp, "writing memory to '%s' failed",
>> +                       filename);
>>               goto exit;
>>           }
>>           addr += l;
>> @@ -843,7 +844,8 @@ void qmp_pmemsave(int64_t addr, int64_t size, const char *filename,
>>               l = size;
>>           cpu_physical_memory_read(addr, buf, l);
>>           if (fwrite(buf, 1, l, f) != l) {
>> -            error_setg(errp, QERR_IO_ERROR);
>> +            error_setg(errp, "writing memory to '%s' failed",
>> +                       filename);
>
> What about including errno with error_setg_errno()?

Sure fwrite() fails with errno reliably set?  The manual page doesn't
mention it...


>>               goto exit;
>>           }
>>           addr += l;