KVM: PPC: Book3S: Facilities to save/restore XICS presentation ctrler state

This adds the ability for userspace to save and restore the state
of the XICS interrupt presentation controllers (ICPs) via the
KVM_GET/SET_ONE_REG interface.  Since there is one ICP per vcpu, we
simply define a new 64-bit register in the ONE_REG space for the ICP
state.  The state includes the CPU priority setting, the pending IPI
priority, and the priority and source number of any pending external
interrupt.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index fb308be..c09d183 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1808,6 +1808,7 @@
   PPC   | KVM_REG_PPC_TLB2PS	| 32
   PPC   | KVM_REG_PPC_TLB3PS	| 32
   PPC   | KVM_REG_PPC_EPTCFG	| 32
+  PPC   | KVM_REG_PPC_ICP_STATE | 64
 
 ARM registers are mapped using the lower 32 bits.  The upper 16 of that
 is the register group type, or coprocessor number: