1 files changed, 34 insertions, 17 deletions

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index ea1600ff52b2..48d3c5d2ecc9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -51,6 +51,7 @@
 #include <asm/hvcall.h>
 #include <asm/switch_to.h>
 #include <asm/smp.h>
+#include <asm/dbell.h>
 #include <linux/gfp.h>
 #include <linux/vmalloc.h>
 #include <linux/highmem.h>
@@ -84,9 +85,35 @@ static DECLARE_BITMAP(default_enabled_hcalls, MAX_HCALL_OPCODE/4 + 1);
 static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
 static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu);
 
+static bool kvmppc_ipi_thread(int cpu)
+{
+        /* On POWER8 for IPIs to threads in the same core, use msgsnd */
+        if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+                preempt_disable();
+                if (cpu_first_thread_sibling(cpu) ==
+                    cpu_first_thread_sibling(smp_processor_id())) {
+                        unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
+                        msg |= cpu_thread_in_core(cpu);
+                        smp_mb();
+                        __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
+                        preempt_enable();
+                        return true;
+                }
+                preempt_enable();
+        }
+
+#if defined(CONFIG_PPC_ICP_NATIVE) && defined(CONFIG_SMP)
+        if (cpu >= 0 && cpu < nr_cpu_ids && paca[cpu].kvm_hstate.xics_phys) {
+                xics_wake_cpu(cpu);
+                return true;
+        }
+#endif
+
+        return false;
+}
+
 static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
 {
-        int me;
         int cpu = vcpu->cpu;
         wait_queue_head_t *wqp;
 
@@ -96,20 +123,12 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
                 ++vcpu->stat.halt_wakeup;
         }
 
-        me = get_cpu();
+        if (kvmppc_ipi_thread(cpu + vcpu->arch.ptid))
+                return;
 
         /* CPU points to the first thread of the core */
-        if (cpu != me && cpu >= 0 && cpu < nr_cpu_ids) {
-#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);
-                else
-#endif
-                if (cpu_online(cpu))
-                        smp_send_reschedule(cpu);
-        }
-        put_cpu();
+        if (cpu >= 0 && cpu < nr_cpu_ids && cpu_online(cpu))
+                smp_send_reschedule(cpu);
 }
 
 /*
@@ -1781,10 +1800,8 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu)
         /* Order stores to hstate.kvm_vcore etc. before store to kvm_vcpu */
         smp_wmb();
         tpaca->kvm_hstate.kvm_vcpu = vcpu;
-#if defined(CONFIG_PPC_ICP_NATIVE) && defined(CONFIG_SMP)
         if (cpu != smp_processor_id())
-                xics_wake_cpu(cpu);
-#endif
+                kvmppc_ipi_thread(cpu);
 }
 
 static void kvmppc_wait_for_nap(void)
@@ -1933,7 +1950,7 @@ static void post_guest_process(struct kvmppc_vcore *vc)
  * Run a set of guest threads on a physical core.
  * Called with vc->lock held.
  */
-static void kvmppc_run_core(struct kvmppc_vcore *vc)
+static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 {
         struct kvm_vcpu *vcpu;
         int i;