KVM: PPC: Book3S HV: Add ICP real mode counters

Add two counters to count how often we generate real-mode ICS resend
and reject events. The counters provide some performance statistics
that could be used in the future to consider if the real mode functions
need further optimizing. The counters are displayed as part of IPC and
ICP state provided by /sys/debug/kernel/powerpc/kvm* for each VM.

Also added two counters that count (approximately) how many times we
don't find an ICP or ICS we're looking for. These are not currently
exposed through sysfs, but can be useful when debugging crashes.

Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/kvm/book3s_xics.h

@@ -83,6 +83,9 @@ struct kvmppc_icp {
 	unsigned long n_rm_check_resend;
 	unsigned long n_rm_reject;
 	unsigned long n_rm_notify_eoi;
+	/* Counters for handling ICP processing in real mode */
+	unsigned long n_check_resend;
+	unsigned long n_reject;
 
 	/* Debug stuff for real mode */
 	union kvmppc_icp_state rm_dbgstate;
@@ -102,6 +105,8 @@ struct kvmppc_xics {
 	u32 max_icsid;
 	bool real_mode;
 	bool real_mode_dbg;
+	u32 err_noics;
+	u32 err_noicp;
 	struct kvmppc_ics *ics[KVMPPC_XICS_MAX_ICS_ID + 1];
 };