KVM: ppc: guest breakpoint support

Allow host userspace to program hardware debug registers to set breakpoints
inside guests.

Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/booke_guest.c b/arch/powerpc/kvm/booke_guest.c
index 9c8ad850c6e3..3cca079975e1 100644
--- a/arch/powerpc/kvm/booke_guest.c
+++ b/arch/powerpc/kvm/booke_guest.c
@@ -410,6 +410,21 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                 break;
         }
 
+        case BOOKE_INTERRUPT_DEBUG: {
+                u32 dbsr;
+
+                vcpu->arch.pc = mfspr(SPRN_CSRR0);
+
+                /* clear IAC events in DBSR register */
+                dbsr = mfspr(SPRN_DBSR);
+                dbsr &= DBSR_IAC1 | DBSR_IAC2 | DBSR_IAC3 | DBSR_IAC4;
+                mtspr(SPRN_DBSR, dbsr);
+
+                run->exit_reason = KVM_EXIT_DEBUG;
+                r = RESUME_HOST;
+                break;
+        }
+
         default:
                 printk(KERN_EMERG "exit_nr %d\n", exit_nr);
                 BUG();