kvm hypervisor: Simplify kvm_for_each_vcpu with kvm_irq_delivery_to_apic

Note that we are using APIC_DM_REMRD which has reserved usage.
In future if APIC_DM_REMRD usage is standardized, then we should
find some other way or go back to old method.

Suggested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

2 files changed, 10 insertions, 20 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index c98f05442325..5439117d5c4c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -689,7 +689,10 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
                 break;
 
         case APIC_DM_REMRD:
-                apic_debug("Ignoring delivery mode 3\n");
+                result = 1;
+                vcpu->arch.pv.pv_unhalted = 1;
+                kvm_make_request(KVM_REQ_EVENT, vcpu);
+                kvm_vcpu_kick(vcpu);
                 break;
 
         case APIC_DM_SMI:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c53741764492..cb276e976203 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5595,27 +5595,14 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
  */
 static void kvm_pv_kick_cpu_op(struct kvm *kvm, unsigned long flags, int apicid)
 {
-        struct kvm_vcpu *vcpu = NULL;
-        int i;
+        struct kvm_lapic_irq lapic_irq;
 
-        kvm_for_each_vcpu(i, vcpu, kvm) {
-                if (!kvm_apic_present(vcpu))
-                        continue;
+        lapic_irq.shorthand = 0;
+        lapic_irq.dest_mode = 0;
+        lapic_irq.dest_id = apicid;
 
-                if (kvm_apic_match_dest(vcpu, 0, 0, apicid, 0))
-                        break;
-        }
-        if (vcpu) {
-                /*
-                 * Setting unhalt flag here can result in spurious runnable
-                 * state when unhalt reset does not happen in vcpu_block.
-                 * But that is harmless since that should soon result in halt.
-                 */
-                vcpu->arch.pv.pv_unhalted = true;
-                /* We need everybody see unhalt before vcpu unblocks */
-                smp_wmb();
-                kvm_vcpu_kick(vcpu);
-        }
+        lapic_irq.delivery_mode = APIC_DM_REMRD;
+        kvm_irq_delivery_to_apic(kvm, 0, &lapic_irq, NULL);
 }
 
 int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)