On Fri, Mar 06, 2015 at 09:05:44AM -0500, John Ferlan wrote:
> Add qemuDomainPinIOThread to handle setting the CPU affinity
> for a specific IOThread
>
> Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
> ---
> include/libvirt/libvirt-domain.h | 9 ++
> src/qemu/qemu_driver.c | 221 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 230 insertions(+)
>
> diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
> index f2f7eb5..11ffd07 100644
> --- a/include/libvirt/libvirt-domain.h
> +++ b/include/libvirt/libvirt-domain.h
> @@ -3218,6 +3218,15 @@ typedef void (*virConnectDomainEventDeviceRemovedCallback)(virConnectPtr conn,
> # define VIR_DOMAIN_TUNABLE_CPU_EMULATORPIN "cputune.emulatorpin"
>
> /**
> + * VIR_DOMAIN_TUNABLE_CPU_IOTHREADSPIN:
> + *
> + * Macro represents formatted pinning for one IOThread specified by id which is
> + * appended to the parameter name, for example "cputune.iothreadpin1",
> + * as VIR_TYPED_PARAM_STRING.
> + */
> +# define VIR_DOMAIN_TUNABLE_CPU_IOTHREADSPIN "cputune.iothreadpin%u"
> +
> +/**
> * VIR_DOMAIN_TUNABLE_CPU_CPU_SHARES:
> *
> * Macro represents proportional weight of the scheduler used on the
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index b37474f..aad08b2 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -5780,6 +5780,226 @@ qemuDomainGetIOThreadsInfo(virDomainPtr dom,
> return ret;
> }
>
> +static int
> +qemuDomainPinIOThread(virDomainPtr dom,
> + unsigned int iothread_id,
> + unsigned char *cpumap,
> + int maplen,
> + unsigned int flags)
> +{
> + if (virDomainPinIOThreadEnsureACL(dom->conn, vm->def, flags) < 0)
> + goto cleanup;
> +
> + if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
> + goto cleanup;
> +
> + if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO) {
> + virReportError(VIR_ERR_OPERATION_INVALID, "%s",
> + _("Changing affinity for IOThread dynamically is "
> + "not allowed when CPU placement is 'auto'"));
> + goto cleanup;
> + }
> +
> + 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)
> + persistentDef = vm->def;
> +
> + /* Coverity didn't realize that targetDef must be set if we got here. */
> + sa_assert(persistentDef);
> +
> + if (!(pcpumap = virBitmapNewData(cpumap, maplen)))
> + goto endjob;
> +
> + if (virBitmapIsAllClear(pcpumap)) {
> + virReportError(VIR_ERR_INVALID_ARG, "%s",
> + _("Empty iothread cpumap list for pinning"));
> + goto endjob;
> + }
> +
> + /* pinning to all physical cpus means resetting,
It doesn't.
By default the iothreads inherit the pinning from the domain's cpumask.
A completely clear bitmap would be a better value to mean resetting,
since it makes no sense otherwise. But getting the cpumask in that case
won't be that easy.
> + * so check if we can reset setting.
> + */
> + if (virBitmapIsAllSet(pcpumap))
> + doReset = true;
> +
> + if (flags & VIR_DOMAIN_AFFECT_LIVE) {
> +
> + if (priv->iothreadpids == NULL) {
> + virReportError(VIR_ERR_OPERATION_INVALID,
> + "%s", _("IOThread affinity is not supported"));
> + goto endjob;
> + }
> +
> + if (iothread_id > priv->niothreadpids) {
> + virReportError(VIR_ERR_INVALID_ARG,
> + _("iothread value out of range %d > %d"),
> + iothread_id, priv->niothreadpids);
> + goto endjob;
> + }
> +
> + if (vm->def->cputune.iothreadspin) {
> + /* The VcpuPinDefCopy works for IOThreads too */
Maybe it should be renamed to something like virDomainPinDefCopy then?
Jan
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