[PATCH v1 3/4] x86/tdx: Expose TDX Guest #VE count in /proc/interrupts

From: Kuppuswamy Sathyanarayanan
Date: Sat Jun 26 2021 - 10:33:00 EST


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 d860fdee9cfe..3a6cfde8ca85 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -1186,6 +1186,8 @@ 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