[libvirt] [PATCHv5 4/8] qemu: bulk stats: implement VCPU group
Peter Krempa
pkrempa at redhat.com
Mon Sep 15 13:41:42 UTC 2014
On 09/15/14 10:48, Francesco Romani wrote:
> This patch implements the VIR_DOMAIN_STATS_VCPU
> group of statistics.
> To do so, this patch also extracts a helper to gather the
> VCpu information.
>
> Signed-off-by: Francesco Romani <fromani at redhat.com>
> ---
> include/libvirt/libvirt.h.in | 1 +
> src/libvirt.c | 12 +++
> src/qemu/qemu_driver.c | 201 +++++++++++++++++++++++++++++--------------
> 3 files changed, 150 insertions(+), 64 deletions(-)
>
> diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
> index a5033ed..4b851a5 100644
> --- a/include/libvirt/libvirt.h.in
> +++ b/include/libvirt/libvirt.h.in
> @@ -2515,6 +2515,7 @@ typedef enum {
> VIR_DOMAIN_STATS_STATE = (1 << 0), /* return domain state */
> VIR_DOMAIN_STATS_CPU_TOTAL = (1 << 1), /* return domain CPU info */
> VIR_DOMAIN_STATS_BALLOON = (1 << 2), /* return domain balloon info */
> + VIR_DOMAIN_STATS_VCPU = (1 << 3), /* return domain virtual CPU info */
> } virDomainStatsTypes;
>
> typedef enum {
> diff --git a/src/libvirt.c b/src/libvirt.c
> index b3b71a0..1d91c99 100644
> --- a/src/libvirt.c
> +++ b/src/libvirt.c
> @@ -21609,6 +21609,18 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
> * "balloon.maximum" - the maximum memory in kiB allowed
> * as unsigned long long.
> *
> + * VIR_DOMAIN_STATS_VCPU: Return virtual CPU statistics.
> + * Due to VCPU hotplug, the vcpu.<num>.* array could be sparse.
> + * The actual size of the array correspond to "vcpu.current".
> + * The array size will never exceed "vcpu.maximum".
> + * The typed parameter keys are in this format:
> + * "vcpu.current" - current number of online virtual CPUs as unsigned int.
> + * "vcpu.maximum" - maximum number of online virtual CPUs as unsigned int.
> + * "vcpu.<num>.state" - state of the virtual CPU <num>, as int
> + * from virVcpuState enum.
> + * "vcpu.<num>.time" - virtual cpu time spent by virtual CPU <num>
> + * as unsigned long long.
> + *
> * Using 0 for @stats returns all stats groups supported by the given
> * hypervisor.
> *
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 745b4f1..4a92f58 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -1380,6 +1380,76 @@ qemuGetProcessInfo(unsigned long long *cpuTime, int *lastCpu, long *vm_rss,
> }
>
>
> +static int
> +qemuDomainHelperGetVcpus(virDomainObjPtr vm, virVcpuInfoPtr info, int maxinfo,
> + unsigned char *cpumaps, int maplen)
> +{
> + int maxcpu, hostcpus;
> + size_t i, v;
> + qemuDomainObjPrivatePtr priv = vm->privateData;
> +
> + if ((hostcpus = nodeGetCPUCount()) < 0)
> + return -1;
> +
> + maxcpu = maplen * 8;
> + if (maxcpu > hostcpus)
> + maxcpu = hostcpus;
> +
> + /* Clamp to actual number of vcpus */
> + if (maxinfo > priv->nvcpupids)
> + maxinfo = priv->nvcpupids;
nvcpupids is 0 if the VM is offline, thus:
> +
> + if (maxinfo >= 1) {
> + if (info != NULL) {
> + memset(info, 0, sizeof(*info) * maxinfo);
> + for (i = 0; i < maxinfo; i++) {
> + info[i].number = i;
You don't initialize the returned CPU numbers to sane values (they stay "0")
> + info[i].state = VIR_VCPU_RUNNING;
> +
> + if (priv->vcpupids != NULL &&
> + qemuGetProcessInfo(&(info[i].cpuTime),
> + &(info[i].cpu),
> + NULL,
> + vm->pid,
> + priv->vcpupids[i]) < 0) {
> + virReportSystemError(errno, "%s",
> + _("cannot get vCPU placement & pCPU time"));
> + return -1;
> + }
> + }
> + }
> +
> + if (cpumaps != NULL) {
> + memset(cpumaps, 0, maplen * maxinfo);
> + if (priv->vcpupids != NULL) {
> + for (v = 0; v < maxinfo; v++) {
> + unsigned char *cpumap = VIR_GET_CPUMAP(cpumaps, maplen, v);
> + virBitmapPtr map = NULL;
> + unsigned char *tmpmap = NULL;
> + int tmpmapLen = 0;
> +
> + if (virProcessGetAffinity(priv->vcpupids[v],
> + &map, maxcpu) < 0)
> + return -1;
> + virBitmapToData(map, &tmpmap, &tmpmapLen);
> + if (tmpmapLen > maplen)
> + tmpmapLen = maplen;
> + memcpy(cpumap, tmpmap, tmpmapLen);
> +
> + VIR_FREE(tmpmap);
> + virBitmapFree(map);
> + }
> + } else {
> + virReportError(VIR_ERR_OPERATION_INVALID,
> + "%s", _("cpu affinity is not available"));
> + return -1;
> + }
> + }
> + }
> + return maxinfo;
> +}
> +
> +
> static virDomainPtr qemuDomainLookupByID(virConnectPtr conn,
> int id)
> {
> @@ -17465,6 +17472,71 @@ qemuDomainGetStatsBalloon(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
> return 0;
> }
>
> +
> +static int
> +qemuDomainGetStatsVcpu(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
> + virDomainObjPtr dom,
> + virDomainStatsRecordPtr record,
> + int *maxparams,
> + unsigned int privflags ATTRIBUTE_UNUSED)
> +{
> + size_t i;
> + int ret = -1;
> + char param_name[VIR_TYPED_PARAM_FIELD_LENGTH];
> + virVcpuInfoPtr cpuinfo = NULL;
> +
> + if (virTypedParamsAddUInt(&record->params,
> + &record->nparams,
> + maxparams,
> + "vcpu.current",
> + (unsigned) dom->def->vcpus) < 0)
> + return -1;
> +
> + if (virTypedParamsAddUInt(&record->params,
> + &record->nparams,
> + maxparams,
> + "vcpu.maximum",
> + (unsigned) dom->def->maxvcpus) < 0)
> + return -1;
> +
> + if (VIR_ALLOC_N(cpuinfo, dom->def->vcpus) < 0)
> + return -1;
> +
> + if (qemuDomainHelperGetVcpus(dom, cpuinfo, dom->def->vcpus,
> + NULL, 0) < 0) {
> + virResetLastError();
> + ret = 0; /* it's ok to be silent and go ahead */
> + goto cleanup;
> + }
> +
> + for (i = 0; i < dom->def->vcpus; i++) {
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "vcpu.%u.state", cpuinfo[i].number);
.. and this then tries to assign the "vcpu.0.state" parameter multiple
times when a VM has multiple CPUs and is offline. I'll add a check that
will skip this if the domain is offline.
> + if (virTypedParamsAddInt(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + cpuinfo[i].state) < 0)
> + goto cleanup;
> +
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "vcpu.%u.time", cpuinfo[i].number);
> + if (virTypedParamsAddULLong(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + cpuinfo[i].cpuTime) < 0)
> + goto cleanup;
> + }
> +
> + ret = 0;
> +
> + cleanup:
> + VIR_FREE(cpuinfo);
> + return ret;
> +}
> +
> +
> typedef int
> (*qemuDomainGetStatsFunc)(virQEMUDriverPtr driver,
> virDomainObjPtr dom,
Peter
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