KVM: Recover IRTE to remapped mode if the interrupt is not single-destination

When the interrupt is not single destination any more, we need
to change back IRTE to remapped mode explicitly.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e2951b6..a4b4aa4 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10764,8 +10764,21 @@ static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
                 */
 
                kvm_set_msi_irq(e, &irq);
-               if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu))
+               if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu)) {
+                       /*
+                        * Make sure the IRTE is in remapped mode if
+                        * we don't handle it in posted mode.
+                        */
+                       ret = irq_set_vcpu_affinity(host_irq, NULL);
+                       if (ret < 0) {
+                               printk(KERN_INFO
+                                  "failed to back to remapped mode, irq: %u\n",
+                                  host_irq);
+                               goto out;
+                       }
+
                        continue;
+               }
 
                vcpu_info.pi_desc_addr = __pa(vcpu_to_pi_desc(vcpu));
                vcpu_info.vector = irq.vector;