x86/irq: Define a global vector for VT-d Posted-Interrupts

Currently, we use a global vector as the Posted-Interrupts
Notification Event for all the vCPUs in the system. We need
to introduce another global vector for VT-d Posted-Interrtups,
which will be used to wakeup the sleep vCPU when an external
interrupt from a direct-assigned device happens for that vCPU.

[ tglx: Removed a gazillion of extra newlines ]

Signed-off-by: Feng Wu <feng.wu@intel.com>
Cc: jiang.liu@linux.intel.com
Link: http://lkml.kernel.org/r/1432026437-16560-4-git-send-email-feng.wu@intel.com
Suggested-by: Yang Zhang <yang.z.zhang@intel.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

8 files changed, 40 insertions, 0 deletions

diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index dc5fa661465f..27ca0afcccd7 100644
--- a/arch/x86/include/asm/entry_arch.h
+++ b/arch/x86/include/asm/entry_arch.h
@@ -23,6 +23,8 @@ BUILD_INTERRUPT(x86_platform_ipi, X86_PLATFORM_IPI_VECTOR)
 #ifdef CONFIG_HAVE_KVM
 BUILD_INTERRUPT3(kvm_posted_intr_ipi, POSTED_INTR_VECTOR,
                  smp_kvm_posted_intr_ipi)
+BUILD_INTERRUPT3(kvm_posted_intr_wakeup_ipi, POSTED_INTR_WAKEUP_VECTOR,
+                 smp_kvm_posted_intr_wakeup_ipi)
 #endif
 
 /*
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 0f5fb6b6567e..986606539395 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -14,6 +14,7 @@ typedef struct {
 #endif
 #ifdef CONFIG_HAVE_KVM
         unsigned int kvm_posted_intr_ipis;
+        unsigned int kvm_posted_intr_wakeup_ipis;
 #endif
         unsigned int x86_platform_ipis; /* arch dependent */
         unsigned int apic_perf_irqs;
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 9ec5d37d8da3..10c80d4f8386 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -29,6 +29,7 @@
 extern asmlinkage void apic_timer_interrupt(void);
 extern asmlinkage void x86_platform_ipi(void);
 extern asmlinkage void kvm_posted_intr_ipi(void);
+extern asmlinkage void kvm_posted_intr_wakeup_ipi(void);
 extern asmlinkage void error_interrupt(void);
 extern asmlinkage void irq_work_interrupt(void);
 
@@ -58,6 +59,7 @@ extern void trace_call_function_single_interrupt(void);
 #define trace_irq_move_cleanup_interrupt  irq_move_cleanup_interrupt
 #define trace_reboot_interrupt  reboot_interrupt
 #define trace_kvm_posted_intr_ipi kvm_posted_intr_ipi
+#define trace_kvm_posted_intr_wakeup_ipi kvm_posted_intr_wakeup_ipi
 #endif /* CONFIG_TRACING */
 
 #ifdef  CONFIG_X86_LOCAL_APIC
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index a80cbb88ea91..8008d06581c7 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -30,6 +30,10 @@ extern void fixup_irqs(void);
 extern void irq_force_complete_move(int);
 #endif
 
+#ifdef CONFIG_HAVE_KVM
+extern void kvm_set_posted_intr_wakeup_handler(void (*handler)(void));
+#endif
+
 extern void (*x86_platform_ipi_callback)(void);
 extern void native_init_IRQ(void);
 extern bool handle_irq(unsigned irq, struct pt_regs *regs);
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index bf55235d7772..0ed29ac13a9d 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -86,6 +86,7 @@
 /* Vector for KVM to deliver posted interrupt IPI */
 #ifdef CONFIG_HAVE_KVM
 #define POSTED_INTR_VECTOR              0xf2
+#define POSTED_INTR_WAKEUP_VECTOR       0xf1
 #endif
 
 /*
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 47b95813dc37..22aadc917868 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -916,6 +916,8 @@ apicinterrupt X86_PLATFORM_IPI_VECTOR \
 #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
 #endif
 
 #ifdef CONFIG_X86_MCE_THRESHOLD
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index be3894512820..90b2f7052f5b 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -242,6 +242,18 @@ __visible void 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;
+
+void kvm_set_posted_intr_wakeup_handler(void (*handler)(void))
+{
+        if (handler)
+                kvm_posted_intr_wakeup_handler = handler;
+        else
+                kvm_posted_intr_wakeup_handler = dummy_handler;
+}
+EXPORT_SYMBOL_GPL(kvm_set_posted_intr_wakeup_handler);
+
 /*
  * Handler for POSTED_INTERRUPT_VECTOR.
  */
@@ -254,6 +266,20 @@ __visible void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
         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)
+{
+        struct pt_regs *old_regs = set_irq_regs(regs);
+
+        entering_ack_irq();
+        inc_irq_stat(kvm_posted_intr_wakeup_ipis);
+        kvm_posted_intr_wakeup_handler();
+        exiting_irq();
+        set_irq_regs(old_regs);
+}
 #endif
 
 __visible void smp_trace_x86_platform_ipi(struct pt_regs *regs)
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index dc1e08d23552..680723a8e4b6 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -144,6 +144,8 @@ static void __init apic_intr_init(void)
 #ifdef CONFIG_HAVE_KVM
         /* IPI for KVM to deliver posted interrupt */
         alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi);
+        /* IPI for KVM to deliver interrupt to wake up tasks */
+        alloc_intr_gate(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi);
 #endif
 
         /* IPI vectors for APIC spurious and error interrupts */