[libvirt] [libvirt-python PATCH 2/2] Support virDomainSetIOThreads
Daniel P. Berrange
berrange at redhat.com
Thu Mar 5 16:44:19 UTC 2015
On Thu, Feb 19, 2015 at 07:59:39AM -0500, John Ferlan wrote:
> Support the libvirt_virDomainSetIOThreads method using code that mimics
> the existing libvirt_virDomainPinVcpuFlags method
>
> The following is a sample session assuming guest 'iothr-gst' has IOThreads
> configured (it's currently running, too)
>
> >>> import libvirt
> >>> con=libvirt.open("qemu:///system")
> >>> dom=con.lookupByName('iothr-gst')
> >>> dom.getIOThreadsInfo()
> [(1, [False, False, True, False], ['/home/vm-images/iothr-vol1']), (2, [False, False, False, True], ['/home/vm-images/iothr-vol2']), (3, [False, False, False, True], [])]
> >>> cpumap=(True,True,True,False)
> >>> dom.setIOThreads(3,cpumap)
> 0
> >>> print dom.getIOThreadsInfo()
> [(1, [False, False, True, False], ['/home/vm-images/iothr-vol1']), (2, [False, False, False, True], ['/home/vm-images/iothr-vol2']), (3, [True, True, True, False], [])]
> >>>
>
> Signed-off-by: John Ferlan <jferlan at redhat.com>
> ---
> generator.py | 1 +
> libvirt-override-api.xml | 8 ++++++
> libvirt-override.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 76 insertions(+)
>
> diff --git a/generator.py b/generator.py
> index 327c896..c79acf1 100755
> --- a/generator.py
> +++ b/generator.py
> @@ -436,6 +436,7 @@ skip_impl = (
> 'virDomainGetEmulatorPinInfo',
> 'virDomainPinEmulator',
> 'virDomainGetIOThreadsInfo',
> + 'virDomainSetIOThreads',
> 'virSecretGetValue',
> 'virSecretSetValue',
> 'virSecretGetUUID',
> diff --git a/libvirt-override-api.xml b/libvirt-override-api.xml
> index e512311..19667b6 100644
> --- a/libvirt-override-api.xml
> +++ b/libvirt-override-api.xml
> @@ -284,6 +284,14 @@
> <arg name='flags' type='int' info='an OR'ed set of virDomainModificationImpact'/>
> <return type='char *' info="list of IOThreads information including the iothread_id, the cpumap, the cpumap length, number of associated resources, and a list of each resource assigned to the iothread_id."/>
> </function>
> + <function name='virDomainSetIOThreads' file='python'>
> + <info>Dynamically change the real CPUs which can be allocated to an IOThread. This function requires privileged access to the hypervisor.</info>
> + <return type='int' info='0 in case of success, -1 in case of failure.'/>
> + <arg name='domain' type='virDomainPtr' info='pointer to domain object'/>
> + <arg name='iothread_val' type='unsigned int' info='iothread_id number'/>
> + <arg name='cpumap' type='unsigned char *' info='pointer to a bit map of real CPUs (in 8-bit bytes) (IN) Each bit set to 1 means that corresponding CPU is usable. Bytes are stored in little-endian order: CPU0-7, 8-15... In each byte, lowest CPU number is least significant bit.'/>
> + <arg name='flags' type='int' info='an OR'ed set of virDomainIOThreadsFlags'/>
> + </function>
> <function name='virDomainSetSchedulerParameters' file='python'>
> <info>Change the scheduler parameters</info>
> <return type='int' info='-1 in case of error, 0 in case of success.'/>
> diff --git a/libvirt-override.c b/libvirt-override.c
> index 17f3bf3..f9af5a9 100644
> --- a/libvirt-override.c
> +++ b/libvirt-override.c
> @@ -2082,6 +2082,72 @@ cleanup:
> return VIR_PY_NONE;
> }
>
> +static PyObject *
> +libvirt_virDomainSetIOThreads(PyObject *self ATTRIBUTE_UNUSED,
> + PyObject *args)
> +{
> + virDomainPtr domain;
> + PyObject *pyobj_domain, *pycpumap;
> + PyObject *ret = NULL;
> + unsigned char *cpumap;
> + int cpumaplen, iothread_val, tuple_size, cpunum;
> + size_t i;
> + unsigned int flags;
> + int i_retval;
> +
> + if (!PyArg_ParseTuple(args, (char *)"OiOI:virDomainSetIOThread",
> + &pyobj_domain, &iothread_val, &pycpumap, &flags))
> + return NULL;
> + domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);
> +
> + if ((cpunum = getPyNodeCPUCount(virDomainGetConnect(domain))) < 0)
> + return VIR_PY_INT_FAIL;
> +
> + if (PyTuple_Check(pycpumap)) {
> + tuple_size = PyTuple_Size(pycpumap);
> + if (tuple_size == -1)
> + return ret;
> + } else {
> + PyErr_SetString(PyExc_TypeError, "Unexpected type, tuple is required");
> + return ret;
> + }
> +
> + cpumaplen = VIR_CPU_MAPLEN(cpunum);
> + if (VIR_ALLOC_N(cpumap, cpumaplen) < 0)
> + return PyErr_NoMemory();
> +
> + for (i = 0; i < tuple_size; i++) {
> + PyObject *flag = PyTuple_GetItem(pycpumap, i);
> + bool b;
> +
> + if (!flag || libvirt_boolUnwrap(flag, &b) < 0)
> + goto cleanup;
> +
> + if (b)
> + VIR_USE_CPU(cpumap, i);
> + else
> + VIR_UNUSE_CPU(cpumap, i);
> + }
> +
> + for (; i < cpunum; i++)
> + VIR_UNUSE_CPU(cpumap, i);
> +
> + flags |= VIR_DOMAIN_IOTHREADS_PIN;
This hardcoding of flags in the python API is a great example of why it
is unsatisfactory to overload multiplex different operations into one
API, instead of just defining separate APis for each.
> + LIBVIRT_BEGIN_ALLOW_THREADS;
> + i_retval = virDomainSetIOThreads(domain, iothread_val,
> + cpumap, cpumaplen, flags);
Regards,
Daniel
--
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