1 files changed, 41 insertions, 2 deletions

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 12d7e4c8dc54..16719af88bcc 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -172,6 +172,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 
 kvmppc_primary_no_guest:
         /* We handle this much like a ceded vcpu */
+        /* put the HDEC into the DEC, since HDEC interrupts don't wake us */
+        mfspr   r3, SPRN_HDEC
+        mtspr   SPRN_DEC, r3
         /* set our bit in napping_threads */
         ld      r5, HSTATE_KVM_VCORE(r13)
         lbz     r7, HSTATE_PTID(r13)
@@ -223,6 +226,12 @@ kvm_novcpu_wakeup:
         cmpdi   r3, 0
         bge     kvm_novcpu_exit
 
+        /* See if our timeslice has expired (HDEC is negative) */
+        mfspr   r0, SPRN_HDEC
+        li      r12, BOOK3S_INTERRUPT_HV_DECREMENTER
+        cmpwi   r0, 0
+        blt     kvm_novcpu_exit
+
         /* Got an IPI but other vcpus aren't yet exiting, must be a latecomer */
         ld      r4, HSTATE_KVM_VCPU(r13)
         cmpdi   r4, 0
@@ -1493,10 +1502,10 @@ kvmhv_do_exit:			/* r12 = trap, r13 = paca */
         cmpwi   r3,0x100        /* Are we the first here? */
         bge     43f
         cmpwi   r12,BOOK3S_INTERRUPT_HV_DECREMENTER
-        beq     40f
+        beq     43f
         li      r0,0
         mtspr   SPRN_HDEC,r0
-40:
+
         /*
          * Send an IPI to any napping threads, since an HDEC interrupt
          * doesn't wake CPUs up from nap.
@@ -2124,6 +2133,27 @@ _GLOBAL(kvmppc_h_cede)		/* r3 = vcpu pointer, r11 = msr, r13 = paca */
         /* save FP state */
         bl      kvmppc_save_fp
 
+        /*
+         * Set DEC to the smaller of DEC and HDEC, so that we wake
+         * no later than the end of our timeslice (HDEC interrupts
+         * don't wake us from nap).
+         */
+        mfspr   r3, SPRN_DEC
+        mfspr   r4, SPRN_HDEC
+        mftb    r5
+        cmpw    r3, r4
+        ble     67f
+        mtspr   SPRN_DEC, r4
+67:
+        /* save expiry time of guest decrementer */
+        extsw   r3, r3
+        add     r3, r3, r5
+        ld      r4, HSTATE_KVM_VCPU(r13)
+        ld      r5, HSTATE_KVM_VCORE(r13)
+        ld      r6, VCORE_TB_OFFSET(r5)
+        subf    r3, r6, r3      /* convert to host TB value */
+        std     r3, VCPU_DEC_EXPIRES(r4)
+
 #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
         ld      r4, HSTATE_KVM_VCPU(r13)
         addi    r3, r4, VCPU_TB_CEDE
@@ -2181,6 +2211,15 @@ kvm_end_cede:
         /* load up FP state */
         bl      kvmppc_load_fp
 
+        /* Restore guest decrementer */
+        ld      r3, VCPU_DEC_EXPIRES(r4)
+        ld      r5, HSTATE_KVM_VCORE(r13)
+        ld      r6, VCORE_TB_OFFSET(r5)
+        add     r3, r3, r6      /* convert host TB to guest TB value */
+        mftb    r7
+        subf    r3, r7, r3
+        mtspr   SPRN_DEC, r3
+
         /* Load NV GPRS */
         ld      r14, VCPU_GPR(R14)(r4)
         ld      r15, VCPU_GPR(R15)(r4)