KVM: PPC: Add get_pvinfo interface to query hypercall instructions

We need to tell the guest the opcodes that make up a hypercall through
interfaces that are controlled by userspace. So we need to add a call
for userspace to allow it to query those opcodes so it can pass them
on.

This is required because the hypercall opcodes can change based on
the hypervisor conditions. If we're running in hardware accelerated
hypervisor mode, a hypercall looks different from when we're running
without hardware acceleration.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 636fc38..3707704 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -414,6 +414,14 @@
 	__u8  pad[64];
 };
 
+/* for KVM_PPC_GET_PVINFO */
+struct kvm_ppc_pvinfo {
+	/* out */
+	__u32 flags;
+	__u32 hcall[4];
+	__u8  pad[108];
+};
+
 #define KVMIO 0xAE
 
 /*
@@ -530,6 +538,7 @@
 #ifdef __KVM_HAVE_XCRS
 #define KVM_CAP_XCRS 56
 #endif
+#define KVM_CAP_PPC_GET_PVINFO 57
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -664,6 +673,8 @@
 /* Available with KVM_CAP_PIT_STATE2 */
 #define KVM_GET_PIT2              _IOR(KVMIO,  0x9f, struct kvm_pit_state2)
 #define KVM_SET_PIT2              _IOW(KVMIO,  0xa0, struct kvm_pit_state2)
+/* Available with KVM_CAP_PPC_GET_PVINFO */
+#define KVM_PPC_GET_PVINFO	  _IOW(KVMIO,  0xa1, struct kvm_ppc_pvinfo)
 
 /*
  * ioctls for vcpu fds