[libvirt] [PATCH RFC 2/7] libxl: implement virDomainMemorystats

[Jim Fehlig]

On 09/08/2015 02:27 AM, Joao Martins wrote:
> Introduce support for domainMemoryStats API call, which
> consequently enables the use of `virsh dommemstat` command to
> query for memory statistics of a domain. We support
> the following statistics: balloon info, available and currently
> in use. swap-in, swap-out, major-faults, minor-faults require
> cooperation of the guest and thus currently not supported.
>
> We build on the data returned from libxl_domain_info and deliver
> it in the virDomainMemoryStat format.
>
> Signed-off-by: Joao Martins <joao.m.martins at oracle.com>
> ---
>   src/libxl/libxl_driver.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 68 insertions(+)
>
> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
> index 101e4c7..43e9e47 100644
> --- a/src/libxl/libxl_driver.c
> +++ b/src/libxl/libxl_driver.c
> @@ -4747,6 +4747,73 @@ libxlDomainGetCPUStats(virDomainPtr dom,
>       return ret;
>   }
>   
> +#define LIBXL_SET_MEMSTAT(TAG, VAL) \
> +        if (i < nr_stats) { \
> +            stats[i].tag = TAG; \
> +            stats[i].val = VAL; \
> +            i++; \
> +        }
> +
> +static int
> +libxlDomainMemoryStats(virDomainPtr dom,
> +                       virDomainMemoryStatPtr stats,
> +                       unsigned int nr_stats,
> +                       unsigned int flags)
> +{
> +    libxlDriverPrivatePtr driver = dom->conn->privateData;
> +    libxlDriverConfigPtr cfg = libxlDriverConfigGet(driver);
> +    virDomainObjPtr vm;
> +    libxl_dominfo d_info;
> +    unsigned mem, maxmem;
> +    size_t i = 0;
> +    int ret = -1;
> +
> +    virCheckFlags(0, -1);
> +
> +    if (!(vm = libxlDomObjFromDomain(dom)))
> +        goto cleanup;
> +
> +    if (virDomainMemoryStatsEnsureACL(dom->conn, vm->def) < 0)
> +        goto cleanup;
> +
> +    if (libxlDomainObjBeginJob(driver, vm, LIBXL_JOB_QUERY) < 0)
> +        goto cleanup;
> +
> +    if (!virDomainObjIsActive(vm)) {
> +        virReportError(VIR_ERR_OPERATION_INVALID,
> +                       "%s", _("domain is not running"));
> +        goto endjob;
> +    }
> +
> +    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 -1;

goto endjob; ?

Also, as you've already noted, another case of missing libxl_dominfo_dispose(). 
But I'll stop mentioning those now :-).

Regards,
Jim

> +    }
> +    mem = d_info.current_memkb;
> +    maxmem = d_info.max_memkb;
> +
> +    LIBXL_SET_MEMSTAT(VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON, maxmem - mem);
> +    LIBXL_SET_MEMSTAT(VIR_DOMAIN_MEMORY_STAT_AVAILABLE, maxmem);
> +    LIBXL_SET_MEMSTAT(VIR_DOMAIN_MEMORY_STAT_RSS, mem);
> +
> +    ret = i;
> +
> + endjob:
> +    if (!libxlDomainObjEndJob(driver, vm)) {
> +        virObjectUnlock(vm);
> +        vm = NULL;
> +    }
> +
> + cleanup:
> +    if (vm)
> +        virObjectUnlock(vm);
> +    return ret;
> +}
> +
> +#undef LIBXL_SET_MEMSTAT
> +
>   static int
>   libxlConnectDomainEventRegisterAny(virConnectPtr conn, virDomainPtr dom, int eventID,
>                                      virConnectDomainEventGenericCallback callback,
> @@ -5340,6 +5407,7 @@ static virHypervisorDriver libxlHypervisorDriver = {
>   #endif
>       .nodeGetFreeMemory = libxlNodeGetFreeMemory, /* 0.9.0 */
>       .nodeGetCellsFreeMemory = libxlNodeGetCellsFreeMemory, /* 1.1.1 */
> +    .domainMemoryStats = libxlDomainMemoryStats, /* 1.2.20 */
>       .domainGetCPUStats = libxlDomainGetCPUStats, /* 1.2.20 */
>       .connectDomainEventRegister = libxlConnectDomainEventRegister, /* 0.9.0 */
>       .connectDomainEventDeregister = libxlConnectDomainEventDeregister, /* 0.9.0 */