[PATCH 3.14 12/83] KVM: PPC: Book3S HV: Fix KVM hang with CONFIG_KVM_XICS=n

From: Greg Kroah-Hartman
Date: Sun May 11 2014 - 15:21:14 EST


3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Anton Blanchard <anton@xxxxxxxxx>

commit 7505258c5fcb0a1cc3c76a47b4cf9506d21d10e6 upstream.

I noticed KVM is broken when KVM in-kernel XICS emulation
(CONFIG_KVM_XICS) is disabled.

The problem was introduced in 48eaef05 (KVM: PPC: Book3S HV: use
xics_wake_cpu only when defined). It used CONFIG_KVM_XICS to wrap
xics_wake_cpu, where CONFIG_PPC_ICP_NATIVE should have been
used.

Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
Acked-by: Scott Wood <scottwood@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/kvm/book3s_hv.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -86,7 +86,7 @@ static void kvmppc_fast_vcpu_kick_hv(str

/* CPU points to the first thread of the core */
if (cpu != me && cpu >= 0 && cpu < nr_cpu_ids) {
-#ifdef CONFIG_KVM_XICS
+#ifdef CONFIG_PPC_ICP_NATIVE
int real_cpu = cpu + vcpu->arch.ptid;
if (paca[real_cpu].kvm_hstate.xics_phys)
xics_wake_cpu(real_cpu);
@@ -1360,9 +1360,7 @@ static void kvmppc_start_thread(struct k
smp_wmb();
#if defined(CONFIG_PPC_ICP_NATIVE) && defined(CONFIG_SMP)
if (cpu != smp_processor_id()) {
-#ifdef CONFIG_KVM_XICS
xics_wake_cpu(cpu);
-#endif
if (vcpu->arch.ptid)
++vc->n_woken;
}


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