Re: [PATCH v2 1/2] tpm: tpm_spapr: Exit on TPM backend failures

[Stefan Berger <stefanb@linux.ibm.com>]

On 7/7/20 12:20 AM, Philippe Mathieu-Daudé wrote:
> Hi Stefan,
>
> On 7/7/20 6:05 AM, Stefan Berger wrote:
>> Exit on TPM backend failures in the same way as the TPM CRB and TIS device
>> models do.
> Maybe the other models are not the best examples ;)

At least they are known to report the error...


>
>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>> ---
>>   hw/tpm/tpm_spapr.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/tpm/tpm_spapr.c b/hw/tpm/tpm_spapr.c
>> index cb4dfd1e6a..8288ab0a15 100644
>> --- a/hw/tpm/tpm_spapr.c
>> +++ b/hw/tpm/tpm_spapr.c
>> @@ -306,7 +306,10 @@ static void tpm_spapr_reset(SpaprVioDevice *dev)
>>                               TPM_SPAPR_BUFFER_MAX);
>>   
>>       tpm_backend_reset(s->be_driver);
>> -    tpm_spapr_do_startup_tpm(s, s->be_buffer_size);
>> +
>> +    if (tpm_spapr_do_startup_tpm(s, s->be_buffer_size) < 0) {
> I don't see error reported, how users can know the cause of the exit?


virt-manager does report the error then. It seems to be taking it from 
the last error message reported in the emulator backend when TPM_INIT 
fails with error code 0x101:

error: internal error: qemu unexpectedly closed the monitor: 
2020-07-07T12:49:28.333928Z qemu-system-ppc64: tpm-emulator: TPM result 
for CMD_INIT: 0x101 operation failed


>
>> +        exit(1);
> What about using this instead?
>
>             qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_ERROR);

It doesn't have any effect, the VM just keeps on running. So the exit(1) 
is better and does report an error.