On 10/19/2018 03:09 PM, John Ferlan wrote:
>
>
> On 10/19/18 7:06 AM, Michal Privoznik wrote:
>> On 10/07/2018 03:00 PM, John Ferlan wrote:
>>> Add functions to set the IOThreadInfo param data for the live guest.
>>>
>>> Based on code originally posted by Pavel Hrdina <phrdina@xxxxxxxxxx>,
>>> but extracted into a separate patch. Note that qapi expects to receive
>>> integer parameters rather than unsigned long long or unsigned int's.
>>> QEMU does save the value in larger signed 64 bit values eventually.
>>>
>>> Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
>>> ---
>>> src/qemu/qemu_monitor.c | 19 +++++++++++++++++++
>>> src/qemu/qemu_monitor.h | 2 ++
>>> src/qemu/qemu_monitor_json.c | 33 +++++++++++++++++++++++++++++++++
>>> src/qemu/qemu_monitor_json.h | 4 ++++
>>> 4 files changed, 58 insertions(+)
>>>
>>> diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
>>> index 7f7013e115..a65d638ab8 100644
>>> --- a/src/qemu/qemu_monitor.c
>>> +++ b/src/qemu/qemu_monitor.c
>>> @@ -4135,6 +4135,25 @@ qemuMonitorGetIOThreads(qemuMonitorPtr mon,
>>> }
>>>
>>>
>>> +/**
>>> + * qemuMonitorSetIOThread:
>>> + * @mon: Pointer to the monitor
>>> + * @iothreadInfo: filled IOThread info with data
>>> + *
>>> + * Alter the specified IOThread's IOThreadInfo values.
>>> + */
>>> +int
>>> +qemuMonitorSetIOThread(qemuMonitorPtr mon,
>>> + qemuMonitorIOThreadInfoPtr iothreadInfo)
>>> +{
>>> + VIR_DEBUG("iothread=%p", iothreadInfo);
>>> +
>>> + QEMU_CHECK_MONITOR(mon);
>>> +
>>> + return qemuMonitorJSONSetIOThread(mon, iothreadInfo);
>>> +}
>>> +
>>> +
>>> /**
>>> * qemuMonitorGetMemoryDeviceInfo:
>>> * @mon: pointer to the monitor
>>> diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
>>> index c2991e2b16..ef71fc6448 100644
>>> --- a/src/qemu/qemu_monitor.h
>>> +++ b/src/qemu/qemu_monitor.h
>>> @@ -1123,6 +1123,8 @@ struct _qemuMonitorIOThreadInfo {
>>> };
>>> int qemuMonitorGetIOThreads(qemuMonitorPtr mon,
>>> qemuMonitorIOThreadInfoPtr **iothreads);
>>> +int qemuMonitorSetIOThread(qemuMonitorPtr mon,
>>> + qemuMonitorIOThreadInfoPtr iothreadInfo);
>>>
>>> typedef struct _qemuMonitorMemoryDeviceInfo qemuMonitorMemoryDeviceInfo;
>>> typedef qemuMonitorMemoryDeviceInfo *qemuMonitorMemoryDeviceInfoPtr;
>>> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
>>> index 2e92984b44..bb1d62b844 100644
>>> --- a/src/qemu/qemu_monitor_json.c
>>> +++ b/src/qemu/qemu_monitor_json.c
>>> @@ -7474,6 +7474,39 @@ qemuMonitorJSONGetIOThreads(qemuMonitorPtr mon,
>>> }
>>>
>>>
>>> +int
>>> +qemuMonitorJSONSetIOThread(qemuMonitorPtr mon,
>>> + qemuMonitorIOThreadInfoPtr iothreadInfo)
>>> +{
>>> + int ret = -1;
>>> + char *path = NULL;
>>> + qemuMonitorJSONObjectProperty prop;
>>> +
>>> + if (virAsprintf(&path, "/objects/iothread%u",
>>> + iothreadInfo->iothread_id) < 0)
>>> + goto cleanup;
>>> +
>>> +#define VIR_IOTHREAD_SET_PROP(propName, propVal) \
>>> + memset(&prop, 0, sizeof(qemuMonitorJSONObjectProperty)); \
>>> + prop.type = QEMU_MONITOR_OBJECT_PROPERTY_INT; \
>>> + prop.val.iv = propVal; \
>>> + if (qemuMonitorJSONSetObjectProperty(mon, path, propName, &prop) < 0) \
>>> + goto cleanup;
>>> +
>>> + VIR_IOTHREAD_SET_PROP("poll-max-ns", iothreadInfo->poll_max_ns)
>>> + VIR_IOTHREAD_SET_PROP("poll-grow", iothreadInfo->poll_grow)
>>> + VIR_IOTHREAD_SET_PROP("poll-shrink", iothreadInfo->poll_shrink)
>>
>> So this is all or nothing approach. All values are set - even though
>> user might request through public API to change just one. I don't think
>> it is a good design. Either we need a monitor API that changes just one
>> value and call it for every typed parameter that user sends to us, or
>> public API implementation must copy the old values into this struct
>> (even though it would be ugly).
>>
>> Michal
>>
>
> Fair complaint - I tried to reuse as much as possible from the initial
> series so that I didn't "waste" time implementing something that in the
> long run wasn't desired. Originally there were lots of checks about what
> was or wasn't set - I just took the path of least resistance.
>
> It should be simple to add flag for each to determine which was set
> before setting them in the object path.
>
> IOW:
>
> #define VIR_IOTHREAD_SET_PROP(propName, propVal) \
> if (iothreadInfo->set_##propVal) { \
This will fly iff zero value can't be set on the monitor. I have no idea
whether it can or can not. If it can be set, then we have to go with
something more clever.
Michal
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list
