[...]
> +#ifdef CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST
> +static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
> +{
> + int r = 0;
> + void __user *argp = (void __user *)cmd->data;
> +
> + switch (cmd->cmd) {
> + case KVM_PV_VM_CREATE: {
> + r = -EINVAL;
> + if (kvm_s390_pv_is_protected(kvm))
> + break;
> +
> + r = kvm_s390_pv_alloc_vm(kvm);
> + if (r)
> + break;
> +
> + mutex_lock(&kvm->lock);
> + kvm_s390_vcpu_block_all(kvm);
> + /* FMT 4 SIE needs esca */
> + r = sca_switch_to_extended(kvm);
> + if (!r)
> + r = kvm_s390_pv_create_vm(kvm);
> + kvm_s390_vcpu_unblock_all(kvm);
> + mutex_unlock(&kvm->lock);
> + break;
> + }
I think KVM_PV_VM_ENABLE/KVM_PV_VM_DISABLE would be a better fit. You're
not creating/deleting VMs, aren't you? All you're doing is allocating
some data and performing some kind of a mode switch.
[...]
> VM_EVENT(kvm, 3, "create cpu %d at 0x%pK, sie block at 0x%pK", id, vcpu,
> vcpu->arch.sie_block);
> trace_kvm_s390_create_vcpu(id, vcpu, vcpu->arch.sie_block);
> @@ -4353,6 +4502,37 @@ long kvm_arch_vcpu_async_ioctl(struct file *filp,
> return -ENOIOCTLCMD;
> }
>
> +#ifdef CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST
> +static int kvm_s390_handle_pv_vcpu(struct kvm_vcpu *vcpu,
> + struct kvm_pv_cmd *cmd)
> +{
> + int r = 0;
> +
> + if (!kvm_s390_pv_is_protected(vcpu->kvm))
> + return -EINVAL;
> +
> + switch (cmd->cmd) {
> + case KVM_PV_VCPU_CREATE: {
> + if (kvm_s390_pv_handle_cpu(vcpu))
> + return -EINVAL;
> +
> + r = kvm_s390_pv_create_cpu(vcpu);
> + break;
> + }
> + case KVM_PV_VCPU_DESTROY: {
> + if (!kvm_s390_pv_handle_cpu(vcpu))
> + return -EINVAL;
> +
> + r = kvm_s390_pv_destroy_cpu(vcpu);
> + break;
> + }
> + default:
> + r = -ENOTTY;
> + }
> + return r;
> +}
I asked this already and didn't get an answer (lost in the flood of
comments :) )
Can't we simply convert all VCPUs via KVM_PV_VM_CREATE and destoy them
via KVM_PV_VM_DESTROY? Then you can easily handle hotplug as well in the
kernel when a new VCPU is created and PV is active - oh and I see you
are already doing that in kvm_arch_vcpu_create(). So that screams for
doing either this a) completely triggered by user space or b) completely
in the kernel. I prefer the latter. One interface less required.
I would assume that no VCPU is allowed to be running inside KVM while
performing the PV switch, which would make this even easier.
--
Thanks,
David / dhildenb
