Re: [PATCH RFC v3 7/9] KVM: add kvm_free_vcpus and kvm_arch_free_vcpus

David Hildenbrand
2017-08-22T14:18:59Z

> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 33a15e176927..0d2d8b0c785c 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -750,6 +750,23 @@ static void kvm_destroy_devices(struct kvm *kvm)
> }
> }
>
> +void kvm_free_vcpus(struct kvm *kvm)
> +{
> + int i;
> +
> + kvm_arch_free_vcpus(kvm);

I wonder if it would be possible to get rid of kvm_arch_free_vcpus(kvm)
completely and simply call

kvm_for_each_vcpu(i, vcpu, kvm)
kvm_arch_vcpu_free(vcpu);

at that point.

Would certainly require some refactoring, and I am not sure if we could
modify the special mmu handling for x86 ("Unpin any mmu pages first.").
But if in doubt, that part could be moved to kvm_arch_destroy_vm(), just
before calling kvm_free_vcpus().

> +
> + mutex_lock(&kvm->lock);
> +
> + i = atomic_read(&kvm->online_vcpus);
> + atomic_set(&kvm->online_vcpus, 0);

i = atomic_xchg(&kvm->online_vcpus, 0);

> +
> + while (i--)
> + kvm->vcpus[i] = NULL;
> +
> + mutex_unlock(&kvm->lock);
> +}
> +
> static void kvm_destroy_vm(struct kvm *kvm)
> {
> int i;
>

--

Thanks,

David