[libvirt] [PATCH RFC 1/7] libxl: implement virDomainGetCPUStats

[Joao Martins]

On 09/17/2015 04:09 AM, Jim Fehlig wrote:
> On 09/08/2015 02:27 AM, Joao Martins wrote:
>> Introduce support for domainGetCPUStats API call and consequently
>> allow us to use `virsh cpu-stats`. The latter returns a more brief
>> output than the one provided by`virsh vcpuinfo`.
>>
>> Signed-off-by: Joao Martins <joao.m.martins at oracle.com>
>> ---
>>   src/libxl/libxl_driver.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 111 insertions(+)
>>
>> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
>> index 5f69b49..101e4c7 100644
>> --- a/src/libxl/libxl_driver.c
>> +++ b/src/libxl/libxl_driver.c
>> @@ -73,6 +73,8 @@ VIR_LOG_INIT("libxl.libxl_driver");
>>   #define LIBXL_CONFIG_FORMAT_XM "xen-xm"
>>   #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
>>   
>> +#define LIBXL_NB_TOTAL_CPU_STAT_PARAM 1
>> +
>>   #define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities"
>>   #define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
>>   
>> @@ -4638,6 +4640,114 @@ libxlDomainIsUpdated(virDomainPtr dom)
>>   }
>>   
>>   static int
>> +libxlDomainGetTotalCPUStats(libxlDriverPrivatePtr driver,
>> +                            virDomainObjPtr vm,
>> +                            virTypedParameterPtr params,
>> +                            unsigned int nparams)
>> +{
>> +    libxlDriverConfigPtr cfg = libxlDriverConfigGet(driver);
>> +    libxl_dominfo d_info;
>> +    int ret = -1;
>> +
>> +    if (nparams == 0)
>> +        return LIBXL_NB_TOTAL_CPU_STAT_PARAM;
>> +
>> +    if (libxl_domain_info(cfg->ctx, &d_info, vm->def->id) != 0) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR,
>> +                       _("libxl_domain_info failed for domain '%d'"),
>> +                       vm->def->id);
>> +        return ret;
>> +    }
>> +
> 
> I see that xl calls libxl_dominfo_dispose() after successful 
> libxl_domain_info(). We might be missing that elsewhere in the libxl driver.
> 
You're right. And I don't do that in all of the other patches of this series
that use libxl_domain_info. Tracking down these calls only libxlReconnectDomain
and libxlDomainGetInfo are missing the dispose. I will send a patch for these two.

>> +    if (virTypedParameterAssign(&params[0], VIR_DOMAIN_CPU_STATS_CPUTIME,
>> +                                VIR_TYPED_PARAM_ULLONG, d_info.cpu_time) < 0)
>> +        return ret;
>> +
>> +    return nparams;
>> +}
>> +
>> +static int
>> +libxlDomainGetPerCPUStats(libxlDriverPrivatePtr driver,
>> +                            virDomainObjPtr vm,
>> +                            virTypedParameterPtr params,
>> +                            unsigned int nparams,
>> +                            int start_cpu,
>> +                            unsigned int ncpus)
> 
> Indentation of parameters is off.
> 
This one slipped slipped me, will fix that. I ran make syntax-check again and
there is one two other tiny issue regarding BlockStats macros, so I am including
those in v2.

>> +{
>> +    libxl_vcpuinfo *vcpuinfo;
>> +    int maxcpu, hostcpus;
>> +    size_t i;
>> +    libxlDriverConfigPtr cfg = libxlDriverConfigGet(driver);
>> +    int ret = -1;
>> +
>> +    if (nparams == 0 && ncpus != 0)
>> +        return LIBXL_NB_TOTAL_CPU_STAT_PARAM;
>> +    else if (nparams == 0)
>> +        return vm->def->maxvcpus;
>> +
>> +    if ((vcpuinfo = libxl_list_vcpu(cfg->ctx, vm->def->id, &maxcpu,
>> +                                    &hostcpus)) == NULL) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR,
>> +                       _("Failed to list vcpus for domain '%d' with libxenlight"),
>> +                       vm->def->id);
>> +        goto cleanup;
>> +    }
>> +
>> +    for (i = start_cpu; i < maxcpu && i < ncpus; ++i) {
>> +        if (virTypedParameterAssign(&params[(i-start_cpu)],
>> +                                    VIR_DOMAIN_CPU_STATS_CPUTIME,
>> +                                    VIR_TYPED_PARAM_ULLONG,
>> +                                    vcpuinfo[i].vcpu_time) < 0)
>> +            goto cleanup;
>> +
>> +        libxl_vcpuinfo_dispose(&vcpuinfo[i]);
> 
> The call to libxl_vcpuinfo_dispose() can be removed
> 
>> +    }
>> +    ret = nparams;
>> +
>> + cleanup:
>> +    VIR_FREE(vcpuinfo);
> 
> if the VIR_FREE() is replaced with libxl_vcpuinfo_list_free().
> 
Got it.

> Other than the few nits, looks good.
> 
> BTW, thanks for the patches! But be warned: I may make slow progress reviewing them.
> 
> Regards,
> Jim
> 
>> +    return ret;
>> +}
>> +
>> +static int
>> +libxlDomainGetCPUStats(virDomainPtr dom,
>> +                       virTypedParameterPtr params,
>> +                       unsigned int nparams,
>> +                       int start_cpu,
>> +                       unsigned int ncpus,
>> +                       unsigned int flags)
>> +{
>> +    libxlDriverPrivatePtr driver = dom->conn->privateData;
>> +    virDomainObjPtr vm = NULL;
>> +    int ret = -1;
>> +
>> +    virCheckFlags(VIR_TYPED_PARAM_STRING_OKAY, -1);
>> +
>> +    if (!(vm = libxlDomObjFromDomain(dom)))
>> +        goto cleanup;
>> +
>> +    if (virDomainGetCPUStatsEnsureACL(dom->conn, vm->def) < 0)
>> +        goto cleanup;
>> +
>> +    if (!virDomainObjIsActive(vm)) {
>> +        virReportError(VIR_ERR_OPERATION_INVALID,
>> +                       "%s", _("domain is not running"));
>> +        goto cleanup;
>> +    }
>> +
>> +    if (start_cpu == -1)
>> +        ret = libxlDomainGetTotalCPUStats(driver, vm, params, nparams);
>> +    else
>> +        ret = libxlDomainGetPerCPUStats(driver, vm, params, nparams,
>> +                                          start_cpu, ncpus);
>> +
>> + cleanup:
>> +    if (vm)
>> +        virObjectUnlock(vm);
>> +    return ret;
>> +}
>> +
>> +static int
>>   libxlConnectDomainEventRegisterAny(virConnectPtr conn, virDomainPtr dom, int eventID,
>>                                      virConnectDomainEventGenericCallback callback,
>>                                      void *opaque, virFreeCallback freecb)
>> @@ -5230,6 +5340,7 @@ static virHypervisorDriver libxlHypervisorDriver = {
>>   #endif
>>       .nodeGetFreeMemory = libxlNodeGetFreeMemory, /* 0.9.0 */
>>       .nodeGetCellsFreeMemory = libxlNodeGetCellsFreeMemory, /* 1.1.1 */
>> +    .domainGetCPUStats = libxlDomainGetCPUStats, /* 1.2.20 */
>>       .connectDomainEventRegister = libxlConnectDomainEventRegister, /* 0.9.0 */
>>       .connectDomainEventDeregister = libxlConnectDomainEventDeregister, /* 0.9.0 */
>>       .domainManagedSave = libxlDomainManagedSave, /* 0.9.2 */
>