[PATCH v3 08/11] KVM: x86: Register empty handler for POSTED_INTR_NESTED_VECTOR IPI

[Liran Alon <liran.alon@xxxxxxxxxx>]

This commit doesn't change semantics.
It is done as a preparation for future commits.

Signed-off-by: Liran Alon <liran.alon@xxxxxxxxxx>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@xxxxxxxxxx>
Reviewed-by: Liam Merwick <liam.merwick@xxxxxxxxxx>
Signed-off-by: Liam Merwick <liam.merwick@xxxxxxxxxx>
---
 arch/x86/include/asm/irq.h |  4 +++-
 arch/x86/kernel/irq.c      | 26 ++++++++++++++++++--------
 arch/x86/kvm/vmx.c         | 13 +++++++++++--
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 2395bb794c7b..1a3f5cb27453 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -29,7 +29,9 @@ static inline int irq_canonicalize(int irq)
 extern void fixup_irqs(void);
 
 #ifdef CONFIG_HAVE_KVM
-extern void kvm_set_posted_intr_wakeup_handler(void (*handler)(void));
+extern void kvm_set_posted_intr_handlers(
+	void (*handler)(void),
+	void (*nested_handler)(void));
 #endif
 
 extern void (*x86_platform_ipi_callback)(void);
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 49cfd9fe7589..1cfe7856eea3 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -279,16 +279,25 @@ __visible void __irq_entry smp_x86_platform_ipi(struct pt_regs *regs)
 
 #ifdef CONFIG_HAVE_KVM
 static void dummy_handler(void) {}
-static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;
+static void (*kvm_posted_intr_handler)(void) = dummy_handler;
+static void (*kvm_nested_posted_intr_handler)(void) = dummy_handler;
 
-void kvm_set_posted_intr_wakeup_handler(void (*handler)(void))
+void kvm_set_posted_intr_handlers(
+	void (*handler)(void),
+	void (*nested_handler)(void))
 {
 	if (handler)
-		kvm_posted_intr_wakeup_handler = handler;
+		kvm_posted_intr_handler = handler;
 	else
-		kvm_posted_intr_wakeup_handler = dummy_handler;
+		kvm_posted_intr_handler = dummy_handler;
+
+	if (nested_handler)
+		kvm_nested_posted_intr_handler = nested_handler;
+	else
+		kvm_nested_posted_intr_handler = dummy_handler;
+
 }
-EXPORT_SYMBOL_GPL(kvm_set_posted_intr_wakeup_handler);
+EXPORT_SYMBOL_GPL(kvm_set_posted_intr_handlers);
 
 /*
  * Handler for POSTED_INTERRUPT_VECTOR.
@@ -304,7 +313,7 @@ __visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
 }
 
 /*
- * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
+ * Handler for POSTED_INTR_VECTOR.
  */
 __visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs)
 {
@@ -312,13 +321,13 @@ __visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs)
 
 	entering_ack_irq();
 	inc_irq_stat(kvm_posted_intr_wakeup_ipis);
-	kvm_posted_intr_wakeup_handler();
+	kvm_posted_intr_handler();
 	exiting_irq();
 	set_irq_regs(old_regs);
 }
 
 /*
- * Handler for POSTED_INTERRUPT_NESTED_VECTOR.
+ * Handler for POSTED_INTR_NESTED_VECTOR.
  */
 __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs)
 {
@@ -326,6 +335,7 @@ __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs)
 
 	entering_ack_irq();
 	inc_irq_stat(kvm_posted_intr_nested_ipis);
+	kvm_nested_posted_intr_handler();
 	exiting_irq();
 	set_irq_regs(old_regs);
 }
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 34ffe929fb41..cb8c52fb0591 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6706,7 +6706,8 @@ static void update_ple_window_actual_max(void)
 }
 
 /*
- * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
+ * Wake-up sleeping vCPUs on current physical CPU as a result
+ * of handling POSTED_INTR_VECTOR at host-side.
  */
 static void wakeup_handler(void)
 {
@@ -6724,6 +6725,13 @@ static void wakeup_handler(void)
 	spin_unlock(&per_cpu(blocked_vcpu_on_cpu_lock, cpu));
 }
 
+/*
+ * Handler for POSTED_INTR_NESTED_VECTOR.
+ */
+static void nested_posted_intr_handler(void)
+{
+}
+
 void vmx_enable_tdp(void)
 {
 	kvm_mmu_set_mask_ptes(VMX_EPT_READABLE_MASK,
@@ -6898,7 +6906,8 @@ static __init int hardware_setup(void)
 		kvm_x86_ops->cancel_hv_timer = NULL;
 	}
 
-	kvm_set_posted_intr_wakeup_handler(wakeup_handler);
+	kvm_set_posted_intr_handlers(
+			wakeup_handler, nested_posted_intr_handler);
 
 	kvm_mce_cap_supported |= MCG_LMCE_P;
 
-- 
1.9.1