Re: [libvirt] [PATCH] qemu_driver: don't set cpu pin for TCG domain

At 2016-10-27 15:41:39, "Martin Kletzander" <mkletzan(a)redhat.com&gt; wrote: >On Sat, Oct 22, 2016 at 05:49:38PM +0800, Chen Hanxiao wrote: >>From: Chen Hanxiao <chenhanxiao(a)gmail.com&gt; >> >> We don't support pinning cpu for TCG domain. >> But we could set it by vcpupin command, >> which result in a failed startup. >> >>Signed-off-by: Chen Hanxiao <chenhanxiao(a)gmail.com&gt; >>--- >> src/qemu/qemu_driver.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> > >Honestly, I think it makes more sense the way it's done now. The API >allows the same thing you would be able to do by 'virsh edit' anyway. >The fact that TCG doesn't support that now doesn't mean it will not >support that in the future and the way it's done now will ensure it >works in that case, I believe. We've already did the same check in qemuDomainRefreshVcpuInfo. If TCG supports pin feature in the future, we could remove these restrictions: 1) in config phase as this patch did. 2) in runtime.

> > >So I would vote for keeping it this way... Maybe a domain capability >element could show whether this is possible or not, but that seems like >an overkill now. Is that any particular major issue you are trying to >resolve by this? E.g. in a mgmt app? Do we have API for showing domain's virt type? I had some VMs with either tcg or kvm virt type. PinVcpu API bring me some troubles then.

Regards, - Chen