KVM: VMX: Register a new IPI for posted interrupt
Posted Interrupt feature requires a special IPI to deliver posted interrupt
to guest. And it should has a high priority so the interrupt will not be
blocked by others.
Normally, the posted interrupt will be consumed by vcpu if target vcpu is
running and transparent to OS. But in some cases, the interrupt will arrive
when target vcpu is scheduled out. And host will see it. So we need to
register a dump handler to handle it.
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index c1d01e6..7272089 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1166,6 +1166,11 @@
apicinterrupt X86_PLATFORM_IPI_VECTOR \
x86_platform_ipi smp_x86_platform_ipi
+#ifdef CONFIG_HAVE_KVM
+apicinterrupt POSTED_INTR_VECTOR \
+ kvm_posted_intr_ipi smp_kvm_posted_intr_ipi
+#endif
+
apicinterrupt THRESHOLD_APIC_VECTOR \
threshold_interrupt smp_threshold_interrupt
apicinterrupt THERMAL_APIC_VECTOR \
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index e4595f1..6ae6ea1 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -228,6 +228,28 @@
set_irq_regs(old_regs);
}
+#ifdef CONFIG_HAVE_KVM
+/*
+ * Handler for POSTED_INTERRUPT_VECTOR.
+ */
+void smp_kvm_posted_intr_ipi(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+
+ ack_APIC_irq();
+
+ irq_enter();
+
+ exit_idle();
+
+ inc_irq_stat(kvm_posted_intr_ipis);
+
+ irq_exit();
+
+ set_irq_regs(old_regs);
+}
+#endif
+
EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
#ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index 7dc4e45..a2a1fbc 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -172,6 +172,10 @@
/* IPI for X86 platform specific use */
alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi);
+#ifdef CONFIG_HAVE_KVM
+ /* IPI for KVM to deliver posted interrupt */
+ alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi);
+#endif
/* IPI vectors for APIC spurious and error interrupts */
alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);