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, 6 insertions, 0 deletions

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 8bb0bf83afc5..9a2db5767ed5 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -169,6 +169,7 @@ struct kvm_pit_config {
 #define KVM_EXIT_S390_UCONTROL    20
 #define KVM_EXIT_WATCHDOG         21
 #define KVM_EXIT_S390_TSCH        22
+#define KVM_EXIT_EPR              23
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 /* Emulate instruction failed. */
@@ -295,6 +296,10 @@ struct kvm_run {
                         __u32 ipb;
                         __u8 dequeued;
                 } s390_tsch;
+                /* KVM_EXIT_EPR */
+                struct {
+                        __u32 epr;
+                } epr;
                 /* Fix the size of the union. */
                 char padding[256];
         };
@@ -656,6 +661,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_PPC_BOOKE_WATCHDOG 83
 #define KVM_CAP_PPC_HTAB_FD 84
 #define KVM_CAP_S390_CSS_SUPPORT 85
+#define KVM_CAP_PPC_EPR 86
 
 #ifdef KVM_CAP_IRQ_ROUTING