[PATCH v2 3/4] x86/tdx: Expose TDX Guest #VE count in /proc/interrupts

[Kuppuswamy Sathyanarayanan]

Add support to expose TD Guest Virtualization Exception (#VE) count
in /proc/interrupts. It is useful in performance analysis of TD Guest.

Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/hardirq.h | 3 +++
 arch/x86/kernel/irq.c          | 6 ++++++
 arch/x86/kernel/traps.c        | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 275e7fd20310..07d79fa9c5c6 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -44,6 +44,9 @@ typedef struct {
 	unsigned int irq_hv_reenlightenment_count;
 	unsigned int hyperv_stimer0_count;
 #endif
+#if IS_ENABLED(CONFIG_INTEL_TDX_GUEST)
+	unsigned int tdg_ve_count;
+#endif
 } ____cacheline_aligned irq_cpustat_t;
 
 DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index e28f6a5d14f1..669869bd46ec 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -181,6 +181,12 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 		seq_printf(p, "%10u ",
 			   irq_stats(j)->kvm_posted_intr_wakeup_ipis);
 	seq_puts(p, "  Posted-interrupt wakeup event\n");
+#endif
+#if IS_ENABLED(CONFIG_INTEL_TDX_GUEST)
+	seq_printf(p, "%*s: ", prec, "TGV");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ", irq_stats(j)->tdg_ve_count);
+	seq_puts(p, "  TDX Guest VE event\n");
 #endif
 	return 0;
 }
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 028622a8ada0..5abc16dd59bb 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -1187,6 +1187,8 @@ DEFINE_IDTENTRY(exc_virtualization_exception)
 
 	RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
 
+	inc_irq_stat(tdg_ve_count);
+
 	/*
 	 * NMIs/Machine-checks/Interrupts will be in a disabled state
 	 * till TDGETVEINFO TDCALL is executed. This prevents #VE
-- 
2.25.1