KVM: PPC: Book3S HV: Save/restore new PMU registers

Power ISA v3.1 has added new performance monitoring unit (PMU) special
purpose registers (SPRs). They are:

Monitor Mode Control Register 3 (MMCR3)
Sampled Instruction Event Register A (SIER2)
Sampled Instruction Event Register B (SIER3)

Add support to save/restore these new SPRs while entering/exiting
guest. Also include changes to support KVM_REG_PPC_MMCR3/SIER2/SIER3.
Add new SPRs to KVM API documentation.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1594996707-3727-6-git-send-email-atrajeev@linux.vnet.ibm.com

tools/arch/powerpc/include/uapi/asm/kvm.h

@@ -640,6 +640,11 @@ struct kvm_ppc_cpu_char {
 #define KVM_REG_PPC_ONLINE	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0xbf)
 #define KVM_REG_PPC_PTCR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc0)
 
+/* POWER10 registers */
+#define KVM_REG_PPC_MMCR3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc1)
+#define KVM_REG_PPC_SIER2	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc2)
+#define KVM_REG_PPC_SIER3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc3)
+
 /* Transactional Memory checkpointed state:
  * This is all GPRs, all VSX regs and a subset of SPRs
  */