[PATCH v4 5/7] migration/dirtyrate: Implement qemuMonitorJSONExtractDirtyRateInfo

[Hao Wang]

I'll take these reviews in my next version. Thanks again!

On 2020/11/11 4:11, Michal Privoznik wrote:
> On 11/7/20 10:41 AM, Hao Wang wrote:
>> Implement qemuMonitorJSONExtractDirtyRateInfo to deal with the return from
>> qmp "query-dirty-rate", and store them in virDomainDirtyRateInfo.
>>
>> Signed-off-by: Hao Wang <wanghao232 at huawei.com>
>> Reviewed-by: Chuan Zheng <zhengchuan at huawei.com>
>> ---
>>   include/libvirt/libvirt-domain.h | 17 +++++++++
>>   src/qemu/qemu_monitor_json.c     | 59 ++++++++++++++++++++++++++++++--
>>   2 files changed, 73 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
>> index b950736b67..51d8685086 100644
>> --- a/include/libvirt/libvirt-domain.h
>> +++ b/include/libvirt/libvirt-domain.h
>> @@ -5096,6 +5096,23 @@ int virDomainBackupBegin(virDomainPtr domain,
>>   char *virDomainBackupGetXMLDesc(virDomainPtr domain,
>>                                   unsigned int flags);
>>   +/**
>> + * virDomainDirtyRateStatus:
>> + *
>> + * Details on the cause of a dirtyrate calculation status.
>> + */
>> +
>> +typedef enum {
>> +    VIR_DOMAIN_DIRTYRATE_UNSTARTED = 0, /* the dirtyrate calculation has not been started */
>> +    VIR_DOMAIN_DIRTYRATE_MEASURING = 1, /* the dirtyrate calculation is measuring */
>> +    VIR_DOMAIN_DIRTYRATE_MEASURED  = 2, /* the dirtyrate calculation is
>> +completed */
>> +
>> +# ifdef VIR_ENUM_SENTINELS
>> +    VIR_DOMAIN_DIRTYRATE_LAST
>> +# endif
>> +} virDomainDirtyRateStatus;
>> +
> 
> As advertised earlier, this doesn't belong into this commit really.
> 
>>   /**
>>    * virDomainDirtyRateInfo:
>>    *
>> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
>> index 1924c7229b..ca7d8d23c0 100644
>> --- a/src/qemu/qemu_monitor_json.c
>> +++ b/src/qemu/qemu_monitor_json.c
>> @@ -9659,12 +9659,61 @@ qemuMonitorJSONCalculateDirtyRate(qemuMonitorPtr mon,
>>   }
>>     +VIR_ENUM_DECL(qemuDomainDirtyRateStatus);
>> +VIR_ENUM_IMPL(qemuDomainDirtyRateStatus,
>> +              VIR_DOMAIN_DIRTYRATE_LAST,
>> +              "unstarted",
>> +              "measuring",
>> +              "measured");
>> +
>> +static int
>> +qemuMonitorJSONExtractDirtyRateInfo(virJSONValuePtr data,
>> +                                    virDomainDirtyRateInfoPtr info)
>> +{
>> +    const char *status;
>> +    int statusID;
>> +
>> +    if (!(status = virJSONValueObjectGetString(data, "status"))) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> +                       _("query-dirty-rate reply was missing 'status' data"));
>> +        return -1;
>> +    }
>> +
>> +    if ((statusID = qemuDomainDirtyRateStatusTypeFromString(status)) < 0) {
>> +        return -1;
> 
> So if qemu sends us some other string, this fails silently.
> 
>> +    }
>> +    info->status = statusID;
>> +
>> +    if ((info->status == VIR_DOMAIN_DIRTYRATE_MEASURED) &&
>> +        (virJSONValueObjectGetNumberLong(data, "dirty-rate", &(info->dirtyRate)) < 0)) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> +                       _("query-dirty-rate reply was missing 'dirty-rate' data"));
>> +        return -1;
>> +    }
>> +
>> +    if (virJSONValueObjectGetNumberLong(data, "start-time", &(info->startTime)) < 0) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> +                       _("query-dirty-rate reply was missing 'start-time' data"));
>> +        return -1;
>> +    }
>> +
>> +    if (virJSONValueObjectGetNumberLong(data, "calc-time", &(info->calcTime)) < 0) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> +                       _("query-dirty-rate reply was missing 'calc-time' data"));
>> +        return -1;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +
>>   int
>>   qemuMonitorJSONQueryDirtyRate(qemuMonitorPtr mon,
>>                                 virDomainDirtyRateInfoPtr info)
>>   {
>>       g_autoptr(virJSONValue) cmd = NULL;
>>       g_autoptr(virJSONValue) reply = NULL;
>> +    virJSONValuePtr data = NULL;
>>         if (!(cmd = qemuMonitorJSONMakeCommand("query-dirty-rate", NULL)))
>>           return -1;
>> @@ -9675,7 +9724,11 @@ qemuMonitorJSONQueryDirtyRate(qemuMonitorPtr mon,
>>       if (qemuMonitorJSONCheckError(cmd, reply) < 0)
>>           return -1;
>>   -    /* TODO: extract dirtyrate data from reply and store in virDomainDirtyRateInfoPtr */
>> -    info->status = 0;
>> -    return 0;
>> +    if (!(data = virJSONValueObjectGetObject(reply, "return"))) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> +                       _("query-dirty-rate reply was missing 'return' data"));
>> +        return -1;
>> +    }
>> +
>> +    return qemuMonitorJSONExtractDirtyRateInfo(data, info);
>>   }
>>
> 
> I think the following should be squashed in:
> 
> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
> index 78ad10bc24..4715b33254 100644
> --- a/src/qemu/qemu_monitor_json.c
> +++ b/src/qemu/qemu_monitor_json.c
> @@ -9680,24 +9680,26 @@ qemuMonitorJSONExtractDirtyRateInfo(virJSONValuePtr data,
>      }
> 
>      if ((statusID = qemuDomainDirtyRateStatusTypeFromString(status)) < 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("Unknown dirty rate status: %s"), status);
>          return -1;
>      }
>      info->status = statusID;
> 
>      if ((info->status == VIR_DOMAIN_DIRTYRATE_MEASURED) &&
> -        (virJSONValueObjectGetNumberLong(data, "dirty-rate", &(info->dirtyRate)) < 0)) {
> +        (virJSONValueObjectGetNumberLong(data, "dirty-rate", &info->dirtyRate) < 0)) {
>          virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>                         _("query-dirty-rate reply was missing 'dirty-rate' data"));
>          return -1;
>      }
> 
> -    if (virJSONValueObjectGetNumberLong(data, "start-time", &(info->startTime)) < 0) {
> +    if (virJSONValueObjectGetNumberLong(data, "start-time", &info->startTime) < 0) {
>          virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>                         _("query-dirty-rate reply was missing 'start-time' data"));
>          return -1;
>      }
> 
> -    if (virJSONValueObjectGetNumberLong(data, "calc-time", &(info->calcTime)) < 0) {
> +    if (virJSONValueObjectGetNumberLong(data, "calc-time", &info->calcTime) < 0) {
>          virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>                         _("query-dirty-rate reply was missing 'calc-time' data"));
>          return -1;
> 
> 
> Michal
> 
> .