Re: [libvirt] [PATCH 1/8] Add new API virDomain{Set, Get}BlockIoTune
On 11/09/2011 11:11 PM, Xu He Jie wrote:
>>> +++ b/include/libvirt/libvirt.h.in
>>> @@ -1640,6 +1640,32 @@ int virDomainBlockJobSetSpeed(virDomainPtr
>>> dom, const char *path,
>>> int virDomainBlockPull(virDomainPtr dom, const char *path,
>>> unsigned long bandwidth, unsigned int flags);
>>>
>>> +/*
>>> + * Block I/O throttling support
>>> + */
>>> +
>>> +typedef struct _virDomainBlockIoTuneInfo virDomainBlockIoTuneInfo;
>>> +struct _virDomainBlockIoTuneInfo {
>> This is not extensible. We've already learned the hard
way that this
>> MUST use virTypedParameter to make future additions painless, rather
>> than hard-coding a particular structure.
>>
virTypedParameter is used between libvirt client and libvirtd. It isn't
used between libvirtd and qemu.
Correct - the public interface must use virTypedParameter. Once we get
to qemu_driver.c, we can then convert from virTypedParameter to a struct
specific to qemu, but that struct should probably be declared in
qemu_monitor.h, and certainly NOT declared in libvirt.h.in.
> Qemu monitor send all the setting parameters at one time within
qmp
> command made by qemuMonitorJSONMakeCommand,
> the union struct virTypeParameter is not very suitable for it. So we
> still use struct virDomainBlockIoTuneInfo
> to keep consistent for qemu monitor command.
I have no problems with qemu monitor using a struct, my heartburn was
with the introduction of a new public struct.
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org