Re: [PATCH v5 1/4] KVM: PPC: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl

[Amit Machhiwal <amachhiw@linux.ibm.com>]

On 2026/08/04 12:55 PM, Gautam Menghani wrote:
> On Wed, Jul 01, 2026 at 10:44:06AM +0530, Amit Machhiwal wrote:
> > Introduce a new capability and ioctl to expose CPU compatibility modes
> > supported by the host processor for nested guests.

<snip>

> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > index 419011097fa8..1cf9a959669e 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -997,6 +997,7 @@ struct kvm_enable_cap {
> >  #define KVM_CAP_S390_KEYOP 247
> >  #define KVM_CAP_S390_VSIE_ESAMODE 248
> >  #define KVM_CAP_S390_HPAGE_2G 249
> > +#define KVM_CAP_PPC_COMPAT_CAPS 250
> >  
> >  struct kvm_irq_routing_irqchip {
> >  	__u32 irqchip;
> > @@ -1350,6 +1351,9 @@ struct kvm_s390_keyop {
> >  #define KVM_GET_DEVICE_ATTR	  _IOW(KVMIO,  0xe2, struct kvm_device_attr)
> >  #define KVM_HAS_DEVICE_ATTR	  _IOW(KVMIO,  0xe3, struct kvm_device_attr)
> >  
> > +/* Available with KVM_CAP_PPC_COMPAT_CAPS */
> > +#define KVM_PPC_GET_COMPAT_CAPS	_IO(KVMIO,  0xe4)
> 
> Can you use another ioctl number for this? This group of ioctls is for
> fds returned by "KVM_CREATE_DEVICE"

Sure, that makes sense. I'll send a v6 with this change soon. Thanks for
for the reviews and testing.

Thanks,
Amit