[PATCH 05/19] KVM: PPC: Book3S HV: add a new KVM device for the XIVE native exploitation mode

[Cédric Le Goater]

On 1/22/19 6:05 AM, Paul Mackerras wrote:
> On Mon, Jan 07, 2019 at 07:43:17PM +0100, Cédric Le Goater wrote:
>> This is the basic framework for the new KVM device supporting the XIVE
>> native exploitation mode. The user interface exposes a new capability
>> and a new KVM device to be used by QEMU.
> 
> [snip]
>> @@ -1039,7 +1039,10 @@ static int kvmppc_book3s_init(void)
>>  #ifdef CONFIG_KVM_XIVE
>>  	if (xive_enabled()) {
>>  		kvmppc_xive_init_module();
>> +		kvmppc_xive_native_init_module();
>>  		kvm_register_device_ops(&kvm_xive_ops, KVM_DEV_TYPE_XICS);
>> +		kvm_register_device_ops(&kvm_xive_native_ops,
>> +					KVM_DEV_TYPE_XIVE);
> 
> I think we want tighter conditions on initializing the xive_native
> stuff and creating the xive device class.  We could have
> xive_enabled() returning true in a guest, and this code will get
> called both by PR KVM and HV KVM (and HV KVM no longer implies that we
> are running bare metal).

So yes, I gave nested a try with kernel_irqchip=on and the nested hypervisor 
(L1) obviously crashes trying to call OPAL. I have tighten the test with : 

	if (xive_enabled() && !kvmhv_on_pseries()) {

for now.

As this is a problem today in 5.0.x, I will send a patch for it if you think
it is correct. I don't think we should bother taking care of the PR case
on P9. Should we ? 

Thanks,

C.
 
>> @@ -1050,8 +1053,10 @@ static int kvmppc_book3s_init(void)
>>  static void kvmppc_book3s_exit(void)
>>  {
>>  #ifdef CONFIG_KVM_XICS
>> -	if (xive_enabled())
>> +	if (xive_enabled()) {
>>  		kvmppc_xive_exit_module();
>> +		kvmppc_xive_native_exit_module();
> 
> Same comment here.
> 
> Paul.
>