From: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
When secondaries are napping in kvm_unsplit_nap() with hwthread_req = 1,
the HMI goes ignored even though subcores are already exited the guest.
Hence HMI keeps waking up secondaries from nap in a loop and secondaries
always go back to nap since no vcore is assigned to them. This makes
impossible for primary thread to get hold of secondary threads resulting
into a soft lockup in KVM path.
This patch fixes this by adding a HMI check just before the thread goes
to unsplit nap.
Signed-off-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
---
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index e8a456e..c5d43b9 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -440,6 +440,12 @@ kvm_no_guest:
* whole-core mode, so we need to nap.
*/
kvm_unsplit_nap:
+ /* Before we head down to nap, check if HMI is pending and handle it */
+ cmpwi r12, BOOK3S_INTERRUPT_HMI
+ bne 55f
+ li r3, 0 /* NULL argument */
+ bl hmi_exception_realmode
+55:
/*
* Ensure that secondary doesn't nap when it has
* its vcore pointer set.
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