On Tue, May 26, 2009 at 11:34:01AM +0300, Avi Kivity wrote:
> Gleb Natapov wrote:
>> Archs are free to use vcpu_id as they see fit. For x86 it is used as
>> vcpu's apic id.
>>
>>
>
> You need a KVM_CAP to inform userspace that the vcpu id has changed meaning.
>
Will add.
>> inline int kvm_is_mmio_pfn(pfn_t pfn)
>> {
>> if (pfn_valid(pfn)) {
>> @@ -1713,15 +1708,12 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu)
>> /*
>> * Creates some virtual cpus. Good luck creating more than one.
>> */
>> -static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
>> +static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
>> {
>> int r;
>> struct kvm_vcpu *vcpu;
>> - if (!valid_vcpu(n))
>> - return -EINVAL;
>> -
>> - vcpu = kvm_arch_vcpu_create(kvm, n);
>> + vcpu = kvm_arch_vcpu_create(kvm, id);
>> if (IS_ERR(vcpu))
>> return PTR_ERR(vcpu);
>> @@ -1732,25 +1724,36 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm
>> *kvm, int n)
>> return r;
>> mutex_lock(&kvm->lock);
>> - if (kvm->vcpus[n]) {
>> - r = -EEXIST;
>> + if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
>> + r = -EINVAL;
>> goto vcpu_destroy;
>> }
>> - kvm->vcpus[n] = vcpu;
>> - if (n == 0)
>> - kvm->bsp_vcpu = vcpu;
>> - mutex_unlock(&kvm->lock);
>> +
>> + for (r = 0; r < atomic_read(&kvm->online_vcpus); r++)
>> + if (kvm->vcpus[r]->vcpu_id == id) {
>> + r = -EEXIST;
>> + goto vcpu_destroy;
>> + }
>> +
>> + BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
>> /* Now it's all set up, let userspace reach it */
>> kvm_get_kvm(kvm);
>> r = create_vcpu_fd(vcpu);
>> - if (r < 0)
>> - goto unlink;
>> + if (r < 0) {
>> + kvm_put_kvm(kvm);
>> + goto vcpu_destroy;
>> + }
>> +
>> + kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
>> + smp_wmb();
>> + atomic_inc(&kvm->online_vcpus);
>> +
>> + if (id == 0)
>> + kvm->bsp_vcpu = vcpu;
>> + mutex_unlock(&kvm->lock);
>> return r;
>> -unlink:
>> - mutex_lock(&kvm->lock);
>> - kvm->vcpus[n] = NULL;
>> vcpu_destroy:
>> mutex_unlock(&kvm->lock);
>> kvm_arch_vcpu_destroy(vcpu);
>>
>
> Don't the vcpu ioctls need to be updated? They get the vcpu id as a
> parameter.
>
Are you sure they do? vcpu ioctls are issued on vcpu fd, no need to pass
vcpu id as a parameter.
--
Gleb.
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