When the guest cedes the vcpu or the vcpu has no guest to
run it naps. Clear the runlatch bit of the vcpu before
napping to indicate an idle cpu.
Signed-off-by: Preeti U Murthy <pre...@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <pau...@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
---
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index b254075..b031f93 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -315,6 +315,11 @@ kvm_no_guest:
li r0, KVM_HWTHREAD_IN_NAP
stb r0, HSTATE_HWTHREAD_STATE(r13)
kvm_do_nap:
+ /* Clear the runlatch bit before napping */
+ mfspr r2, SPRN_CTRLF
+ clrrdi r2, r2, 1
+ mtspr SPRN_CTRLT, r2
+
li r3, LPCR_PECE0
mfspr r4, SPRN_LPCR
rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
@@ -2005,8 +2010,13 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
/*
* Take a nap until a decrementer or external or doobell interrupt
- * occurs, with PECE1, PECE0 and PECEDP set in LPCR
+ * occurs, with PECE1, PECE0 and PECEDP set in LPCR. Also clear the
+ * runlatch bit before napping.
*/
+ mfspr r2, SPRN_CTRLF
+ clrrdi r2, r2, 1
+ mtspr SPRN_CTRLT, r2
+
li r0,1
stb r0,HSTATE_HWTHREAD_REQ(r13)
mfspr r5,SPRN_LPCR
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