Liu ping fan wrote:
Suppose the following scene,
Firstly, creating 10 kvm_vcpu for guest to take the advantage of
multi-core. Now, reclaiming some of the kvm_vcpu, so we can limit the
guest's usage of cpu. Then what about the kvm_vcpu unused? Currently
they are just idle in kernel, but with this patch, we can remove them.
Then why not write it in the changelog?
+void kvm_arch_vcpu_zap(struct work_struct *work)
+{
+ struct kvm_vcpu *vcpu = container_of(work, struct kvm_vcpu,
+ zap_work);
+ struct kvm *kvm = vcpu->kvm;
- atomic_set(&kvm->online_vcpus, 0);
- mutex_unlock(&kvm->lock);
+ kvm_clear_async_pf_completion_queue(vcpu);
+ kvm_unload_vcpu_mmu(vcpu);
+ kvm_arch_vcpu_free(vcpu);
+ kvm_put_kvm(kvm);
}
zap is really a good name for this?
zap = destroy, so I think it is OK.
Stronger than that.
My dictionary says "to destroy sth suddenly and with force."
In the case of shadow pages, I see what the author wanted to mean by "zap".
In your case, the host really destroy a VCPU suddenly?
The guest have to unplug it before, I guess.
If you just mean "destroy", why not use it?
+#define kvm_for_each_vcpu(vcpu, kvm) \
+ list_for_each_entry_rcu(vcpu,&kvm->vcpus, list)
Is this macro really worth it?
_rcu shows readers important information, I think.
I guest kvm_for_each_vcpu is designed for hiding the details of
internal implement, and currently it is implemented by array, and my
patch will change it to linked-list,
so IMO, we can still hide the details.
Then why are you doing
list_add_rcu(&vcpu->list, &kvm->vcpus);
without introducing kvm_add_vcpu()?
You are just hiding part of the interface.
I believe this kind of incomplete abstraction should not be added.
The original code was complex enough to introduce a macro, but
list_for_each_entry_rcu(vcpu, &kvm->vcpus, list)
is simple and shows clear meaning by itself.
Takuya
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
