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>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index 7dc4e459c2b3..a2a1fbc594ff 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -172,6 +172,10 @@ static void __init apic_intr_init(void)
 
         /* 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);