[PATCH v4 07/38] perf: core/x86: Register a new vector for KVM GUEST PMI

[Mingwei Zhang]

From: Xiong Zhang <xiong.y.zhang@xxxxxxxxxxxxxxx>

Create a new vector in the host IDT for kvm guest PMI handling within
mediated passthrough vPMU. In addition, guest PMI handler registration
is added into x86_set_kvm_irq_handler().

This is the preparation work to support mediated passthrough vPMU to
handle kvm guest PMIs without interference from PMI handler of the host
PMU.

Signed-off-by: Xiong Zhang <xiong.y.zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
 arch/x86/include/asm/hardirq.h                |  1 +
 arch/x86/include/asm/idtentry.h               |  1 +
 arch/x86/include/asm/irq_vectors.h            |  5 ++++-
 arch/x86/kernel/idt.c                         |  1 +
 arch/x86/kernel/irq.c                         | 21 +++++++++++++++++++
 .../beauty/arch/x86/include/asm/irq_vectors.h |  5 ++++-
 6 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 6ffa8b75f4cd..25fac35b9a29 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -19,6 +19,7 @@ typedef struct {
 	unsigned int kvm_posted_intr_ipis;
 	unsigned int kvm_posted_intr_wakeup_ipis;
 	unsigned int kvm_posted_intr_nested_ipis;
+	unsigned int kvm_guest_pmis;
 #endif
 	unsigned int x86_platform_ipis;	/* arch dependent */
 	unsigned int apic_perf_irqs;
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index ad5c68f0509d..b0cb3220e1bb 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -745,6 +745,7 @@ DECLARE_IDTENTRY_SYSVEC(IRQ_WORK_VECTOR,		sysvec_irq_work);
 DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_VECTOR,		sysvec_kvm_posted_intr_ipi);
 DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_WAKEUP_VECTOR,	sysvec_kvm_posted_intr_wakeup_ipi);
 DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR,	sysvec_kvm_posted_intr_nested_ipi);
+DECLARE_IDTENTRY_SYSVEC(KVM_GUEST_PMI_VECTOR,	        sysvec_kvm_guest_pmi_handler);
 #else
 # define fred_sysvec_kvm_posted_intr_ipi		NULL
 # define fred_sysvec_kvm_posted_intr_wakeup_ipi		NULL
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 47051871b436..250cdab11306 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -77,7 +77,10 @@
  */
 #define IRQ_WORK_VECTOR			0xf6
 
-/* 0xf5 - unused, was UV_BAU_MESSAGE */
+#if IS_ENABLED(CONFIG_KVM)
+#define KVM_GUEST_PMI_VECTOR		0xf5
+#endif
+
 #define DEFERRED_ERROR_VECTOR		0xf4
 
 /* Vector on which hypervisor callbacks will be delivered */
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index f445bec516a0..0bec4c7e2308 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -157,6 +157,7 @@ static const __initconst struct idt_data apic_idts[] = {
 	INTG(POSTED_INTR_VECTOR,		asm_sysvec_kvm_posted_intr_ipi),
 	INTG(POSTED_INTR_WAKEUP_VECTOR,		asm_sysvec_kvm_posted_intr_wakeup_ipi),
 	INTG(POSTED_INTR_NESTED_VECTOR,		asm_sysvec_kvm_posted_intr_nested_ipi),
+	INTG(KVM_GUEST_PMI_VECTOR,		asm_sysvec_kvm_guest_pmi_handler),
 # endif
 # ifdef CONFIG_IRQ_WORK
 	INTG(IRQ_WORK_VECTOR,			asm_sysvec_irq_work),
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 18cd418fe106..b29714e23fc4 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -183,6 +183,12 @@ 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");
+
+	seq_printf(p, "%*s: ", prec, "VPMU");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ",
+			   irq_stats(j)->kvm_guest_pmis);
+	seq_puts(p, " KVM GUEST PMI\n");
 #endif
 #ifdef CONFIG_X86_POSTED_MSI
 	seq_printf(p, "%*s: ", prec, "PMN");
@@ -311,6 +317,7 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_x86_platform_ipi)
 #if IS_ENABLED(CONFIG_KVM)
 static void dummy_handler(void) {}
 static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;
+static void (*kvm_guest_pmi_handler)(void) = dummy_handler;
 
 void x86_set_kvm_irq_handler(u8 vector, void (*handler)(void))
 {
@@ -321,6 +328,10 @@ void x86_set_kvm_irq_handler(u8 vector, void (*handler)(void))
 	    (handler == dummy_handler ||
 	     kvm_posted_intr_wakeup_handler == dummy_handler))
 		kvm_posted_intr_wakeup_handler = handler;
+	else if (vector == KVM_GUEST_PMI_VECTOR &&
+		 (handler == dummy_handler ||
+		  kvm_guest_pmi_handler == dummy_handler))
+		kvm_guest_pmi_handler = handler;
 	else
 		WARN_ON_ONCE(1);
 
@@ -356,6 +367,16 @@ DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_nested_ipi)
 	apic_eoi();
 	inc_irq_stat(kvm_posted_intr_nested_ipis);
 }
+
+/*
+ * Handler for KVM_GUEST_PMI_VECTOR.
+ */
+DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_guest_pmi_handler)
+{
+	apic_eoi();
+	inc_irq_stat(kvm_guest_pmis);
+	kvm_guest_pmi_handler();
+}
 #endif
 
 #ifdef CONFIG_X86_POSTED_MSI
diff --git a/tools/perf/trace/beauty/arch/x86/include/asm/irq_vectors.h b/tools/perf/trace/beauty/arch/x86/include/asm/irq_vectors.h
index 47051871b436..250cdab11306 100644
--- a/tools/perf/trace/beauty/arch/x86/include/asm/irq_vectors.h
+++ b/tools/perf/trace/beauty/arch/x86/include/asm/irq_vectors.h
@@ -77,7 +77,10 @@
  */
 #define IRQ_WORK_VECTOR			0xf6
 
-/* 0xf5 - unused, was UV_BAU_MESSAGE */
+#if IS_ENABLED(CONFIG_KVM)
+#define KVM_GUEST_PMI_VECTOR		0xf5
+#endif
+
 #define DEFERRED_ERROR_VECTOR		0xf4
 
 /* Vector on which hypervisor callbacks will be delivered */
-- 
2.49.0.395.g12beb8f557-goog