1 files changed, 12 insertions, 1 deletions

diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 7737146af3fb..50d411d946eb 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -66,12 +66,14 @@
 
 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
 {
+        unsigned long nr_jiffies;
+
         if (vcpu->arch.tcr & TCR_DIE) {
                 /* The decrementer ticks at the same rate as the timebase, so
                  * that's how we convert the guest DEC value to the number of
                  * host ticks. */
-                unsigned long nr_jiffies;
 
+                vcpu->arch.dec_jiffies = mftb();
                 nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
                 mod_timer(&vcpu->arch.dec_timer,
                           get_jiffies_64() + nr_jiffies);
@@ -211,6 +213,15 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
                         /* Note: SPRG4-7 are user-readable, so we don't get
                          * a trap. */
 
+                        case SPRN_DEC:
+                        {
+                                u64 jd = mftb() - vcpu->arch.dec_jiffies;
+                                vcpu->arch.gpr[rt] = vcpu->arch.dec - jd;
+#ifdef DEBUG_EMUL
+                                printk(KERN_INFO "mfDEC: %x - %llx = %lx\n", vcpu->arch.dec, jd, vcpu->arch.gpr[rt]);
+#endif
+                                break;
+                        }
                         default:
                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
                                 if (emulated == EMULATE_FAIL) {