KVM: PPC: BookE: Implement EPR exit

The External Proxy Facility in FSL BookE chips allows the interrupt
controller to automatically acknowledge an interrupt as soon as a
core gets its pending external interrupt delivered.

Today, user space implements the interrupt controller, so we need to
check on it during such a cycle.

This patch implements logic for user space to enable EPR exiting,
disable EPR exiting and EPR exiting itself, so that user space can
acknowledge an interrupt when an external interrupt has successfully
been delivered into the guest vcpu.

Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 964f4475f55c..940ec806187e 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -306,7 +306,7 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
 {
         int allowed = 0;
         ulong msr_mask = 0;
-        bool update_esr = false, update_dear = false;
+        bool update_esr = false, update_dear = false, update_epr = false;
         ulong crit_raw = vcpu->arch.shared->critical;
         ulong crit_r1 = kvmppc_get_gpr(vcpu, 1);
         bool crit;
@@ -330,6 +330,9 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
                 keep_irq = true;
         }
 
+        if ((priority == BOOKE_IRQPRIO_EXTERNAL) && vcpu->arch.epr_enabled)
+                update_epr = true;
+
         switch (priority) {
         case BOOKE_IRQPRIO_DTLB_MISS:
         case BOOKE_IRQPRIO_DATA_STORAGE:
@@ -408,6 +411,8 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
                         set_guest_esr(vcpu, vcpu->arch.queued_esr);
                 if (update_dear == true)
                         set_guest_dear(vcpu, vcpu->arch.queued_dear);
+                if (update_epr == true)
+                        kvm_make_request(KVM_REQ_EPR_EXIT, vcpu);
 
                 new_msr &= msr_mask;
 #if defined(CONFIG_64BIT)
@@ -615,6 +620,13 @@ int kvmppc_core_check_requests(struct kvm_vcpu *vcpu)
                 r = 0;
         }
 
+        if (kvm_check_request(KVM_REQ_EPR_EXIT, vcpu)) {
+                vcpu->run->epr.epr = 0;
+                vcpu->arch.epr_needed = true;
+                vcpu->run->exit_reason = KVM_EXIT_EPR;
+                r = 0;
+        }
+
         return r;
 }