[PATCH 14/14] KVM: PPC: Book3S HV: Counters for passthrough IRQ stats

[Suresh Warrier]

Add VCPU stat counters to track affinity for passthrough
interrupts.

pthru_all: Counts all passthrough interrupts whose IRQ mappings have
           been cached in the kvmppc_passthru_irq_map cache.
pthru_host: Counts all cached passthrough interrupts that were injected
	    from the host through kvm_set_irq.
pthru_bad_aff: Counts how many cached passthrough interrupts have
               bad affinity (receiving CPU is not running VCPU that is
	       the target of the virtual interrupt in the guest).

Signed-off-by: Suresh Warrier <warrier at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kvm_host.h  | 3 +++
 arch/powerpc/kvm/book3s.c            | 3 +++
 arch/powerpc/kvm/book3s_hv_rm_xics.c | 7 +++++++
 3 files changed, 13 insertions(+)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 558d195..9230b1a 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -128,6 +128,9 @@ struct kvm_vcpu_stat {
 	u32 ld_slow;
 	u32 st_slow;
 #endif
+	u32 pthru_all;
+	u32 pthru_host;
+	u32 pthru_bad_aff;
 };
 
 enum kvm_exit_types {
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 1b4f5bd..b3d44b1 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -65,6 +65,9 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	{ "ld_slow",     VCPU_STAT(ld_slow) },
 	{ "st",          VCPU_STAT(st) },
 	{ "st_slow",     VCPU_STAT(st_slow) },
+	{ "pthru_all",       VCPU_STAT(pthru_all) },
+	{ "pthru_host",      VCPU_STAT(pthru_host) },
+	{ "pthru_bad_aff",   VCPU_STAT(pthru_bad_aff) },
 	{ NULL }
 };
 
diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c
index e2bbfdf..4004a35 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_xics.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c
@@ -696,6 +696,7 @@ static struct kvmppc_irq_map *get_irqmap_gsi(
 unsigned long irq_map_err;
 
 /*
+ * Count affinity for passthrough IRQs.
  * Change affinity to CPU running the target VCPU.
  */
 static void ics_set_affinity_passthru(struct ics_irq_state *state,
@@ -708,17 +709,23 @@ static void ics_set_affinity_passthru(struct ics_irq_state *state,
 	s16 intr_cpu;
 	u32 pcpu;
 
+	vcpu->stat.pthru_all++;
+
 	intr_cpu = state->intr_cpu;
 
 	if  (intr_cpu == -1)
 		return;
 
+	vcpu->stat.pthru_host++;
+
 	state->intr_cpu = -1;
 
 	pcpu = cpu_first_thread_sibling(raw_smp_processor_id());
 	if (intr_cpu == pcpu)
 		return;
 
+	vcpu->stat.pthru_bad_aff++;
+
 	pimap = kvmppc_get_passthru_irqmap(vcpu);
 	if (likely(pimap)) {
 		irq_map = get_irqmap_gsi(pimap, irq);
-- 
1.8.3.4