x86/entry: Convert KVM vectors to IDTENTRY_SYSVEC*

Convert KVM specific system vectors to IDTENTRY_SYSVEC*:

The two empty stub handlers which only increment the stats counter do no
need to run on the interrupt stack. Use IDTENTRY_SYSVEC_SIMPLE for them.

The wakeup handler does more work and runs on the interrupt stack.

None of these handlers need to save and restore the irq_regs pointer.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202119.555715519@linutronix.de

7 files changed, 15 insertions, 42 deletions

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 2301f62d08e6..ea1f2930876c 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -956,13 +956,6 @@ apicinterrupt3 \num \sym \do_sym
 POP_SECTION_IRQENTRY
 .endm
 
-
-#ifdef CONFIG_HAVE_KVM
-apicinterrupt3 POSTED_INTR_VECTOR		kvm_posted_intr_ipi		smp_kvm_posted_intr_ipi
-apicinterrupt3 POSTED_INTR_WAKEUP_VECTOR	kvm_posted_intr_wakeup_ipi	smp_kvm_posted_intr_wakeup_ipi
-apicinterrupt3 POSTED_INTR_NESTED_VECTOR	kvm_posted_intr_nested_ipi	smp_kvm_posted_intr_nested_ipi
-#endif
-
 #ifdef CONFIG_SMP
 apicinterrupt RESCHEDULE_VECTOR			reschedule_interrupt		smp_reschedule_interrupt
 #endif
diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index 69a5320a4673..a01bb74244ac 100644
--- a/arch/x86/include/asm/entry_arch.h
+++ b/arch/x86/include/asm/entry_arch.h
@@ -13,10 +13,3 @@
 #ifdef CONFIG_SMP
 BUILD_INTERRUPT(reschedule_interrupt,RESCHEDULE_VECTOR)
 #endif
-
-#ifdef CONFIG_HAVE_KVM
-BUILD_INTERRUPT(kvm_posted_intr_ipi, POSTED_INTR_VECTOR)
-BUILD_INTERRUPT(kvm_posted_intr_wakeup_ipi, POSTED_INTR_WAKEUP_VECTOR)
-BUILD_INTERRUPT(kvm_posted_intr_nested_ipi, POSTED_INTR_NESTED_VECTOR)
-#endif
-
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 7281c7e3a0f6..fd5e7c8825e1 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -29,10 +29,6 @@
 #include <asm/sections.h>
 
 /* Interrupt handlers registered during init_IRQ */
-extern asmlinkage void kvm_posted_intr_ipi(void);
-extern asmlinkage void kvm_posted_intr_wakeup_ipi(void);
-extern asmlinkage void kvm_posted_intr_nested_ipi(void);
-
 extern asmlinkage void reschedule_interrupt(void);
 
 #ifdef	CONFIG_X86_LOCAL_APIC
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index cd752e6cf5af..7f7c80bd272c 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -628,6 +628,12 @@ DECLARE_IDTENTRY_SYSVEC(IRQ_WORK_VECTOR,		sysvec_irq_work);
 # endif
 #endif
 
+#ifdef CONFIG_HAVE_KVM
+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);
+#endif
+
 #undef X86_TRAP_OTHER
 
 #endif
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index c7c43e86805a..f73dd3f8b043 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -26,9 +26,6 @@ extern void fixup_irqs(void);
 
 #ifdef CONFIG_HAVE_KVM
 extern void kvm_set_posted_intr_wakeup_handler(void (*handler)(void));
-extern __visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs);
-extern __visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs);
-extern __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs);
 #endif
 
 extern void (*x86_platform_ipi_callback)(void);
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 3d811d058f2e..faaadd430882 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -135,9 +135,9 @@ static const __initconst struct idt_data apic_idts[] = {
 	INTG(LOCAL_TIMER_VECTOR,		asm_sysvec_apic_timer_interrupt),
 	INTG(X86_PLATFORM_IPI_VECTOR,		asm_sysvec_x86_platform_ipi),
 # ifdef CONFIG_HAVE_KVM
-	INTG(POSTED_INTR_VECTOR,		kvm_posted_intr_ipi),
-	INTG(POSTED_INTR_WAKEUP_VECTOR,		kvm_posted_intr_wakeup_ipi),
-	INTG(POSTED_INTR_NESTED_VECTOR,		kvm_posted_intr_nested_ipi),
+	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),
 # 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 7e3005274f83..181060247e3c 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -298,41 +298,29 @@ EXPORT_SYMBOL_GPL(kvm_set_posted_intr_wakeup_handler);
 /*
  * Handler for POSTED_INTERRUPT_VECTOR.
  */
-__visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
+DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_ipi)
 {
-	struct pt_regs *old_regs = set_irq_regs(regs);
-
-	entering_ack_irq();
+	ack_APIC_irq();
 	inc_irq_stat(kvm_posted_intr_ipis);
-	exiting_irq();
-	set_irq_regs(old_regs);
 }
 
 /*
  * Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
  */
-__visible void smp_kvm_posted_intr_wakeup_ipi(struct pt_regs *regs)
+DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_posted_intr_wakeup_ipi)
 {
-	struct pt_regs *old_regs = set_irq_regs(regs);
-
-	entering_ack_irq();
+	ack_APIC_irq();
 	inc_irq_stat(kvm_posted_intr_wakeup_ipis);
 	kvm_posted_intr_wakeup_handler();
-	exiting_irq();
-	set_irq_regs(old_regs);
 }
 
 /*
  * Handler for POSTED_INTERRUPT_NESTED_VECTOR.
  */
-__visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs)
+DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_nested_ipi)
 {
-	struct pt_regs *old_regs = set_irq_regs(regs);
-
-	entering_ack_irq();
+	ack_APIC_irq();
 	inc_irq_stat(kvm_posted_intr_nested_ipis);
-	exiting_irq();
-	set_irq_regs(old_regs);
 }
 #endif