KVM: PPC: Don't return -ENOTSUPP to userspace in ioctls

ENOTSUPP is a linux only thingy, the value of which is unknown to
userspace, not to be confused with ENOTSUP which linux maps to
EOPNOTSUPP, as permitted by POSIX [1]:

[EOPNOTSUPP]
Operation not supported on socket. The type of socket (address family
or protocol) does not support the requested operation. A conforming
implementation may assign the same values for [EOPNOTSUPP] and [ENOTSUP].

Return -EOPNOTSUPP instead of -ENOTSUPP for the following ioctls:
- KVM_GET_FPU for Book3s and BookE
- KVM_SET_FPU for Book3s and BookE
- KVM_GET_DIRTY_LOG for BookE

This doesn't affect QEMU which doesn't call the KVM_GET_FPU and
KVM_SET_FPU ioctls on POWER anyway since they are not supported,
and _buggily_ ignores anything but -EPERM for KVM_GET_DIRTY_LOG.

[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html

Signed-off-by: Greg Kurz <[e-mail]>
Acked-by: Thadeu Lima de Souza Cascardo <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>

arch/powerpc/kvm/book3s.c

···
 
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id,

arch/powerpc/kvm/booke.c

···
 
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
···
 
 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 
 void kvmppc_core_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)