On Thu, 2015-01-22 at 10:06 +0000, Daniel P. Berrange wrote:
On Thu, Jan 22, 2015 at 04:55:02PM +0800, Zhu Guihua wrote:
On Wed, 2015-01-21 at 09:42 +0000, Daniel P. Berrange wrote:
On Wed, Jan 21, 2015 at 04:00:52PM +0800, Zhu Guihua wrote:
If you apply the folowing patchset [PATCH v3 0/7] cpu: add device_add foo-x86_64-cpu support https://lists.nongnu.org/archive/html/qemu-devel/2015-01/msg01552.html, and [PATCH v2 00/11] cpu: add i386 cpu hot remove support https://lists.nongnu.org/archive/html/qemu-devel/2015-01/msg01557.html, qemu can support hotplug and hot-unplug cpu device.
So this patch series will make libvirt support hotplug and hot-unplug cpu device for qemu driver, and now only supports one cpu driver which is 'qemu64-x86_64-cpu'.
The cpu device's xml like this: <cpu driver='qemu64-x86_64-cpu' apic_id='3'>
Do we really need to expose this 'qemu64-x86_64-cpu' string to apps. It feels like a rather low level QEMU private implementation detail to me that apps should not need to know or care about. I think libvirt should always just do the right thing to make cpu hotplug work.
There is a need to use more cpu model. 'qemu64-x86_64-cpu' is only one example, we will realize more driver in future.
Can you give an example of why we will need more than one model ? It seems pretty crazy to me that we will need to specify two CPU models for CPUs, both "Nehalem" / "Opteron" / etc and this new CPU model. It makes little sense from the user / app POV IMHO.
In future, this will become an advanced feature for specific user. If user may not specific a model, we will specific a default model. I think this feature is mainly for test environment. If you want to test different cpu model's performance, this feature will be essential. Regards, Zhu
Regards, Daniel