From: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxxxxxxx> 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 <mahesh@xxxxxxxxxxxxxxxxxx> --- 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. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
