[libvirt] [PATCH v5 09/10] qemu: Add support to Add/Delete IOThreads
Peter Krempa
pkrempa at redhat.com
Mon Apr 27 14:45:39 UTC 2015
On Fri, Apr 24, 2015 at 12:06:01 -0400, John Ferlan wrote:
> Add qemuDomainAddIOThread and qemuDomainDelIOThread in order to add or
> remove an IOThread to/from the host either for live or config optoins
>
> The implementation for the 'live' option will use the iothreadpids list
> in order to make decision, while the 'config' option will use the
> iothreadids list. Additionally, for deletion each may have to adjust
> the iothreadpin list.
>
> IOThreads are implemented by qmp objects, the code makes use of the existing
> qemuMonitorAddObject or qemuMonitorDelObject APIs.
>
> Signed-off-by: John Ferlan <jferlan at redhat.com>
> ---
> src/conf/domain_audit.c | 9 ++
> src/conf/domain_audit.h | 6 +
> src/libvirt_private.syms | 1 +
> src/qemu/qemu_driver.c | 380 +++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 396 insertions(+)
>
...
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 1fac0b8..4ae63c6 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -6154,6 +6154,384 @@ qemuDomainPinIOThread(virDomainPtr dom,
> return ret;
> }
>
> +static int
> +qemuDomainHotplugAddIOThread(virQEMUDriverPtr driver,
> + virDomainObjPtr vm,
> + unsigned int iothread_id)
> +{
> + qemuDomainObjPrivatePtr priv = vm->privateData;
> + char *alias = NULL;
> + size_t idx;
> + int rc = -1;
> + int ret = -1;
> + unsigned int orig_niothreads = vm->def->iothreads;
> + unsigned int exp_niothreads = vm->def->iothreads;
> + int new_niothreads = 0;
> + qemuMonitorIOThreadInfoPtr *new_iothreads = NULL;
> + virCgroupPtr cgroup_iothread = NULL;
> + char *mem_mask = NULL;
> + virDomainIOThreadIDDefPtr iothrid;
> + virBitmapPtr cpumask;
> +
> + if (virDomainIOThreadIDFind(vm->def, iothread_id)) {
> + virReportError(VIR_ERR_INVALID_ARG,
> + _("an IOThread is already using iothread_id '%u'"),
> + iothread_id);
> + goto cleanup;
> + }
> +
> + if (virAsprintf(&alias, "iothread%u", iothread_id) < 0)
> + return -1;
> +
> + qemuDomainObjEnterMonitor(driver, vm);
> +
> + rc = qemuMonitorAddObject(priv->mon, "iothread", alias, NULL);
> + exp_niothreads++;
> + if (rc < 0)
> + goto exit_monitor;
> +
> + /* After hotplugging the IOThreads we need to re-detect the
> + * IOThreads thread_id's, adjust the cgroups, thread affinity,
> + * and add the thread_id to the vm->def->iothreadids list.
> + */
> + if ((new_niothreads = qemuMonitorGetIOThreads(priv->mon,
> + &new_iothreads)) < 0)
> + goto exit_monitor;
> +
> + if (qemuDomainObjExitMonitor(driver, vm) < 0)
> + goto cleanup;
> +
> + if (new_niothreads != exp_niothreads) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("got wrong number of IOThread ids from QEMU monitor. "
> + "got %d, wanted %d"),
> + new_niothreads, exp_niothreads);
> + vm->def->iothreads = new_niothreads;
> + goto cleanup;
> + }
> + vm->def->iothreads = exp_niothreads;
> +
> + if (virDomainNumatuneGetMode(vm->def->numa, -1) ==
> + VIR_DOMAIN_NUMATUNE_MEM_STRICT &&
> + virDomainNumatuneMaybeFormatNodeset(vm->def->numa,
> + priv->autoNodeset,
> + &mem_mask, -1) < 0)
> + goto cleanup;
> +
> +
> + /*
> + * If we've successfully added an IOThread, find out where we added it
> + * in the QEMU IOThread list, so we can add it to our iothreadids list
> + */
> + for (idx = 0; idx < new_niothreads; idx++) {
> + if (STREQ(new_iothreads[idx]->name, alias))
> + break;
> + }
> +
> + if (idx == new_niothreads) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("cannot find new IOThread '%u' in QEMU monitor."),
> + iothread_id);
> + goto cleanup;
> + }
> +
> + if (!(iothrid = virDomainIOThreadIDAdd(vm->def, iothread_id)))
> + goto cleanup;
> +
> + iothrid->thread_id = new_iothreads[idx]->thread_id;
> +
> + /* Add IOThread to cgroup if present */
> + if (priv->cgroup) {
> + cgroup_iothread =
> + qemuDomainAddCgroupForThread(priv->cgroup,
> + VIR_CGROUP_THREAD_IOTHREAD,
> + iothread_id, mem_mask,
> + iothrid->thread_id);
> + if (!cgroup_iothread)
> + goto cleanup;
> + }
> +
> + if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)
> + cpumask = priv->autoCpuset;
> + else
> + cpumask = vm->def->cpumask;
> +
> + if (cpumask) {
> + if (qemuDomainHotplugPinThread(cpumask, iothread_id,
> + iothrid->thread_id, cgroup_iothread) < 0)
> + goto cleanup;
> + }
> +
> + ret = 0;
> +
> + cleanup:
> + if (new_iothreads) {
> + for (idx = 0; idx < new_niothreads; idx++)
> + qemuMonitorIOThreadInfoFree(new_iothreads[idx]);
> + VIR_FREE(new_iothreads);
> + }
> + VIR_FREE(mem_mask);
> + virDomainAuditIOThread(vm, orig_niothreads, new_niothreads,
> + "update", rc == 0);
> + virCgroupFree(&cgroup_iothread);
> + VIR_FREE(alias);
> + return ret;
> +
> + exit_monitor:
> + ignore_value(qemuDomainObjExitMonitor(driver, vm));
> + goto cleanup;
> +}
> +
> +static int
> +qemuDomainHotplugDelIOThread(virQEMUDriverPtr driver,
> + virDomainObjPtr vm,
> + unsigned int iothread_id)
> +{
> + qemuDomainObjPrivatePtr priv = vm->privateData;
> + size_t idx;
> + char *alias = NULL;
> + int rc = -1;
> + int ret = -1;
> + unsigned int orig_niothreads = vm->def->iothreads;
> + unsigned int exp_niothreads = vm->def->iothreads;
> + int new_niothreads = 0;
> + qemuMonitorIOThreadInfoPtr *new_iothreads = NULL;
> +
> + /* Normally would use virDomainIOThreadIDFind, but we need the index
> + * from whence to delete for later...
> + */
> + for (idx = 0; idx < vm->def->niothreadids; idx++) {
> + if (iothread_id == vm->def->iothreadids[idx]->iothread_id)
> + break;
> + }
> +
> + if (idx == vm->def->niothreadids) {
> + virReportError(VIR_ERR_INVALID_ARG,
> + _("cannot find IOThread '%u' in iothreadids list"),
> + iothread_id);
> + return -1;
> + }
> +
> + if (virAsprintf(&alias, "iothread%u", iothread_id) < 0)
> + return -1;
> +
> + qemuDomainObjEnterMonitor(driver, vm);
> +
> + rc = qemuMonitorDelObject(priv->mon, alias);
> + exp_niothreads--;
> + if (rc < 0)
> + goto exit_monitor;
> +
> + if ((new_niothreads = qemuMonitorGetIOThreads(priv->mon,
> + &new_iothreads)) < 0)
> + goto exit_monitor;
> +
> + if (qemuDomainObjExitMonitor(driver, vm) < 0)
> + goto cleanup;
> +
> + if (new_niothreads != exp_niothreads) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("got wrong number of IOThread ids from QEMU monitor. "
> + "got %d, wanted %d"),
> + new_niothreads, exp_niothreads);
> + vm->def->iothreads = new_niothreads;
> + goto cleanup;
> + }
> + vm->def->iothreads = exp_niothreads;
> +
> + virDomainIOThreadIDDel(vm->def, iothread_id);
> +
> + virDomainIOThreadSchedDelId(vm->def, iothread_id);
> +
> + if (qemuDomainDelCgroupForThread(priv->cgroup,
> + VIR_CGROUP_THREAD_IOTHREAD,
> + iothread_id) < 0)
> + goto cleanup;
> +
> + ret = 0;
> +
> + cleanup:
> + if (new_iothreads) {
> + for (idx = 0; idx < new_niothreads; idx++)
> + qemuMonitorIOThreadInfoFree(new_iothreads[idx]);
> + VIR_FREE(new_iothreads);
> + }
> + virDomainAuditIOThread(vm, orig_niothreads, new_niothreads,
> + "update", rc == 0);
> + VIR_FREE(alias);
> + return ret;
> +
> + exit_monitor:
> + ignore_value(qemuDomainObjExitMonitor(driver, vm));
> + goto cleanup;
> +}
> +
> +static int
> +qemuDomainChgIOThread(virQEMUDriverPtr driver,
> + virDomainObjPtr vm,
> + unsigned int iothread_id,
> + bool add,
> + unsigned int flags)
> +{
> + virQEMUDriverConfigPtr cfg = NULL;
> + virCapsPtr caps = NULL;
> + qemuDomainObjPrivatePtr priv;
> + virCgroupPtr cgroup_temp = NULL;
> + virBitmapPtr all_nodes = NULL;
> + char *all_nodes_str = NULL;
> + char *mem_mask = NULL;
It's nice that you've finally deleted the piece of code that has to deal
with the DMA memory allocation issue with vCPU hotplug. You also could
have deleted the corresponding variables that are now unused ...
> + virDomainDefPtr persistentDef;
> + int ret = -1;
> +
> + cfg = virQEMUDriverGetConfig(driver);
> +
> + if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
> + goto cleanup;
> +
> + priv = vm->privateData;
> +
> + if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
> + goto cleanup;
> +
> + if (virDomainLiveConfigHelperMethod(caps, driver->xmlopt, vm, &flags,
> + &persistentDef) < 0)
> + goto endjob;
> +
> + if (flags & VIR_DOMAIN_AFFECT_LIVE) {
> + if (!virDomainObjIsActive(vm)) {
> + virReportError(VIR_ERR_OPERATION_INVALID, "%s",
> + _("cannot change IOThreads for an inactive domain"));
> + goto endjob;
> + }
> +
> + if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_OBJECT_IOTHREAD)) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("IOThreads not supported with this binary"));
> + goto endjob;
> + }
> +
> + if (add) {
> + if (qemuDomainHotplugAddIOThread(driver, vm, iothread_id) < 0)
> + goto endjob;
> + } else {
> + if (qemuDomainHotplugDelIOThread(driver, vm, iothread_id) < 0)
> + goto endjob;
> + }
> +
> + if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm) < 0)
> + goto endjob;
> + }
> +
> + if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
> + if (add) {
> + if (!virDomainIOThreadIDAdd(persistentDef, iothread_id))
> + goto endjob;
> +
> + persistentDef->iothreads++;
> + } else {
> + virDomainIOThreadIDDefPtr iothrid;
> + if (!(iothrid = virDomainIOThreadIDFind(persistentDef,
> + iothread_id))) {
> + virReportError(VIR_ERR_INVALID_ARG,
> + _("cannot find IOThread '%u' in persistent "
> + "iothreadids"),
> + iothread_id);
> + goto cleanup;
> + }
> +
> + virDomainIOThreadIDDel(persistentDef, iothread_id);
> + virDomainIOThreadSchedDelId(persistentDef, iothread_id);
> + persistentDef->iothreads--;
> + }
> +
> + if (virDomainSaveConfig(cfg->configDir, persistentDef) < 0)
> + goto endjob;
> + }
> +
> + ret = 0;
> +
> + endjob:
> + if (mem_mask) {
> + virErrorPtr err = virSaveLastError();
> + virCgroupSetCpusetMems(cgroup_temp, mem_mask);
> + virSetError(err);
> + virFreeError(err);
> + }
> + qemuDomainObjEndJob(driver, vm);
> +
> + cleanup:
> + VIR_FREE(mem_mask);
> + VIR_FREE(all_nodes_str);
> + virBitmapFree(all_nodes);
> + virCgroupFree(&cgroup_temp);
> + virObjectUnref(caps);
> + virObjectUnref(cfg);
> + return ret;
> +}
ACK if you clean up qemuDomainChgIOThread()
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