diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index a1d344d..6818713 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -180,6 +180,19 @@ KVM_CHECK_EXTENSION ioctl() to determine the value for max_vcpus at run-time.
 If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4
 cpus max.
 
+On powerpc using book3s_hv mode, the vcpus are mapped onto virtual
+threads in one or more virtual CPU cores.  (This is because the
+hardware requires all the hardware threads in a CPU core to be in the
+same partition.)  The KVM_CAP_PPC_SMT capability indicates the number
+of vcpus per virtual core (vcore).  The vcore id is obtained by
+dividing the vcpu id by the number of vcpus per vcore.  The vcpus in a
+given vcore will always be in the same physical core as each other
+(though that might be a different physical core from time to time).
+Userspace can control the threading (SMT) mode of the guest by its
+allocation of vcpu ids.  For example, if userspace wants
+single-threaded guest vcpus, it should make all vcpu ids be a multiple
+of the number of vcpus per vcore.
+
 4.8 KVM_GET_DIRTY_LOG (vm ioctl)
 
 Capability: basic
diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h
index c3ec990..471bb3d 100644
--- a/arch/powerpc/include/asm/kvm.h
+++ b/arch/powerpc/include/asm/kvm.h
@@ -24,6 +24,7 @@
 
 /* Select powerpc specific features in <linux/kvm.h> */
 #define __KVM_HAVE_SPAPR_TCE
+#define __KVM_HAVE_PPC_SMT
 
 struct kvm_regs {
 	__u64 pc;
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index b7b0395..9cfd543 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -78,6 +78,8 @@ struct kvmppc_host_state {
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	struct kvm_vcpu *kvm_vcpu;
+	struct kvmppc_vcore *kvm_vcore;
+	unsigned long xics_phys;
 	u64 dabr;
 	u64 host_mmcr[3];
 	u32 host_pmc[6];
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 5616e39..0d6d569 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -25,10 +25,14 @@
 #include <linux/interrupt.h>
 #include <linux/types.h>
 #include <linux/kvm_types.h>
+#include <linux/threads.h>
+#include <linux/spinlock.h>
 #include <linux/kvm_para.h>
 #include <asm/kvm_asm.h>
+#include <asm/processor.h>
 
-#define KVM_MAX_VCPUS 1
+#define KVM_MAX_VCPUS		NR_CPUS
+#define KVM_MAX_VCORES		NR_CPUS
 #define KVM_MEMORY_SLOTS 32
 /* memory slots that does not exposed to userspace */
 #define KVM_PRIVATE_MEM_SLOTS 4
@@ -167,9 +171,34 @@ struct kvm_arch {
 	int tlbie_lock;
 	struct list_head spapr_tce_tables;
 	unsigned short last_vcpu[NR_CPUS];
+	struct kvmppc_vcore *vcores[KVM_MAX_VCORES];
 #endif /* CONFIG_KVM_BOOK3S_64_HV */
 };
 
+/*
+ * Struct for a virtual core.
+ * Note: entry_exit_count combines an entry count in the bottom 8 bits
+ * and an exit count in the next 8 bits.  This is so that we can
+ * atomically increment the entry count iff the exit count is 0
+ * without taking the lock.
+ */
+struct kvmppc_vcore {
+	int n_runnable;
+	int n_blocked;
+	int num_threads;
+	int entry_exit_count;
+	int n_woken;
+	int nap_count;
+	u16 pcpu;
+	u8 vcore_running;
+	u8 in_guest;
+	struct list_head runnable_threads;
+	spinlock_t lock;
+};
+
+#define VCORE_ENTRY_COUNT(vc)	((vc)->entry_exit_count & 0xff)
+#define VCORE_EXIT_COUNT(vc)	((vc)->entry_exit_count >> 8)
+
 struct kvmppc_pte {
 	ulong eaddr;
 	u64 vpage;
@@ -365,14 +394,29 @@ struct kvm_vcpu_arch {
 	struct slb_shadow *slb_shadow;
 	struct dtl *dtl;
 	struct dtl *dtl_end;
+
+	struct kvmppc_vcore *vcore;
+	int ret;
 	int trap;
+	int state;
+	int ptid;
+	wait_queue_head_t cpu_run;
+
 	struct kvm_vcpu_arch_shared *shared;
 	unsigned long magic_page_pa; /* phys addr to map the magic page to */
 	unsigned long magic_page_ea; /* effect. addr to map the magic page to */
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	struct kvm_vcpu_arch_shared shregs;
+
+	struct list_head run_list;
+	struct task_struct *run_task;
+	struct kvm_run *kvm_run;
 #endif
 };
 
+#define KVMPPC_VCPU_BUSY_IN_HOST	0
+#define KVMPPC_VCPU_BLOCKED		1
+#define KVMPPC_VCPU_RUNNABLE		2
+
 #endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 99f6fcf..6ef7344 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -33,6 +33,9 @@
 #else
 #include <asm/kvm_booke.h>
 #endif
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
+#include <asm/paca.h>
+#endif
 
 enum emulation_result {
 	EMULATE_DONE,         /* no further processing */
@@ -169,4 +172,14 @@ int kvmppc_set_sregs_ivor(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs);
 
 void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid);
 
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
+{
+	paca[cpu].kvm_hstate.xics_phys = addr;
+}
+#else
+static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
+{}
+#endif
+
 #endif /* __POWERPC_KVM_PPC_H__ */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index c70d106..d0f2387 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -471,6 +471,10 @@ int main(void)
 	DEFINE(VCPU_FAULT_DAR, offsetof(struct kvm_vcpu, arch.fault_dar));
 	DEFINE(VCPU_LAST_INST, offsetof(struct kvm_vcpu, arch.last_inst));
 	DEFINE(VCPU_TRAP, offsetof(struct kvm_vcpu, arch.trap));
+	DEFINE(VCPU_PTID, offsetof(struct kvm_vcpu, arch.ptid));
+	DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_count));
+	DEFINE(VCORE_NAP_COUNT, offsetof(struct kvmppc_vcore, nap_count));
+	DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest));
 	DEFINE(VCPU_SVCPU, offsetof(struct kvmppc_vcpu_book3s, shadow_vcpu) -
 			   offsetof(struct kvmppc_vcpu_book3s, vcpu));
 	DEFINE(VCPU_SLB_E, offsetof(struct kvmppc_slb, orige));
@@ -530,6 +534,8 @@ int main(void)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HV
 	HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
+	HSTATE_FIELD(HSTATE_KVM_VCORE, kvm_vcore);
+	HSTATE_FIELD(HSTATE_XICS_PHYS, xics_phys);
 	HSTATE_FIELD(HSTATE_MMCR, host_mmcr);
 	HSTATE_FIELD(HSTATE_PMC, host_pmc);
 	HSTATE_FIELD(HSTATE_PURR, host_purr);
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 163c041..5bc06fd 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -49,19 +49,32 @@ BEGIN_FTR_SECTION
 	 * state loss at this time.
 	 */
 	mfspr	r13,SPRN_SRR1
-	rlwinm	r13,r13,47-31,30,31
-	cmpwi	cr0,r13,1
-	bne	1f
-	b	.power7_wakeup_noloss
-1:	cmpwi	cr0,r13,2
-	bne	1f
-	b	.power7_wakeup_loss
+	rlwinm.	r13,r13,47-31,30,31
+	beq	9f
+
+	/* waking up from powersave (nap) state */
+	cmpwi	cr1,r13,2
 	/* Total loss of HV state is fatal, we could try to use the
 	 * PIR to locate a PACA, then use an emergency stack etc...
 	 * but for now, let's just stay stuck here
 	 */
-1:	cmpwi	cr0,r13,3
-	beq	.
+	bgt	cr1,.
+	GET_PACA(r13)
+
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+	lbz	r0,PACAPROCSTART(r13)
+	cmpwi	r0,0x80
+	bne	1f
+	li	r0,0
+	stb	r0,PACAPROCSTART(r13)
+	b	kvm_start_guest
+1:
+#endif
+
+	beq	cr1,2f
+	b	.power7_wakeup_noloss
+2:	b	.power7_wakeup_loss
+9:
 END_FTR_SECTION_IFSET(CPU_FTR_HVMODE_206)
 #endif /* CONFIG_PPC_P7_NAP */
 	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S
index f8f0bc7..3a70845 100644
--- a/arch/powerpc/kernel/idle_power7.S
+++ b/arch/powerpc/kernel/idle_power7.S
@@ -73,7 +73,6 @@ _GLOBAL(power7_idle)
 	b	.
 
 _GLOBAL(power7_wakeup_loss)
-	GET_PACA(r13)
 	ld	r1,PACAR1(r13)
 	REST_NVGPRS(r1)
 	REST_GPR(2, r1)
@@ -87,7 +86,6 @@ _GLOBAL(power7_wakeup_loss)
 	rfid
 
 _GLOBAL(power7_wakeup_noloss)
-	GET_PACA(r13)
 	ld	r1,PACAR1(r13)
 	ld	r4,_MSR(r1)
 	ld	r5,_NIP(r1)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6fe469e..36b6d98 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -39,6 +39,7 @@
 #include <asm/mmu_context.h>
 #include <asm/lppaca.h>
 #include <asm/processor.h>
+#include <asm/cputhreads.h>
 #include <linux/gfp.h>
 #include <linux/sched.h>
 #include <linux/vmalloc.h>
@@ -51,12 +52,16 @@
 void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	local_paca->kvm_hstate.kvm_vcpu = vcpu;
+	local_paca->kvm_hstate.kvm_vcore = vcpu->arch.vcore;
 }
 
 void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
 {
 }
 
+static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu);
+static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu);
+
 void kvmppc_vcpu_block(struct kvm_vcpu *vcpu)
 {
 	u64 now;
@@ -74,11 +79,15 @@ void kvmppc_vcpu_block(struct kvm_vcpu *vcpu)
 			      HRTIMER_MODE_REL);
 	}
 
+	kvmppc_vcpu_blocked(vcpu);
+
 	kvm_vcpu_block(vcpu);
 	vcpu->stat.halt_wakeup++;
 
 	if (vcpu->arch.dec_expires != ~(u64)0)
 		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+
+	kvmppc_vcpu_unblocked(vcpu);
 }
 
 void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr)
@@ -429,9 +438,16 @@ int kvmppc_core_check_processor_compat(void)
 struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 {
 	struct kvm_vcpu *vcpu;
-	int err = -ENOMEM;
+	int err = -EINVAL;
+	int core;
+	struct kvmppc_vcore *vcore;
 	unsigned long lpcr;
 
+	core = id / threads_per_core;
+	if (core >= KVM_MAX_VCORES)
+		goto out;
+
+	err = -ENOMEM;
 	vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
 	if (!vcpu)
 		goto out;
@@ -454,6 +470,38 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 
 	kvmppc_mmu_book3s_hv_init(vcpu);
 
+	/*
+	 * Some vcpus may start out in stopped state.  If we initialize
+	 * them to busy-in-host state they will stop other vcpus in the
+	 * vcore from running.  Instead we initialize them to blocked
+	 * state, effectively considering them to be stopped until we
+	 * see the first run ioctl for them.
+	 */
+	vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
+
+	init_waitqueue_head(&vcpu->arch.cpu_run);
+
+	mutex_lock(&kvm->lock);
+	vcore = kvm->arch.vcores[core];
+	if (!vcore) {
+		vcore = kzalloc(sizeof(struct kvmppc_vcore), GFP_KERNEL);
+		if (vcore) {
+			INIT_LIST_HEAD(&vcore->runnable_threads);
+			spin_lock_init(&vcore->lock);
+		}
+		kvm->arch.vcores[core] = vcore;
+	}
+	mutex_unlock(&kvm->lock);
+
+	if (!vcore)
+		goto free_vcpu;
+
+	spin_lock(&vcore->lock);
+	++vcore->num_threads;
+	++vcore->n_blocked;
+	spin_unlock(&vcore->lock);
+	vcpu->arch.vcore = vcore;
+
 	return vcpu;
 
 free_vcpu:
@@ -468,21 +516,121 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
 	kfree(vcpu);
 }
 
+static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+
+	spin_lock(&vc->lock);
+	vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
+	++vc->n_blocked;
+	if (vc->n_runnable > 0 &&
+	    vc->n_runnable + vc->n_blocked == vc->num_threads) {
+		vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
+					arch.run_list);
+		wake_up(&vcpu->arch.cpu_run);
+	}
+	spin_unlock(&vc->lock);
+}
+
+static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+
+	spin_lock(&vc->lock);
+	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
+	--vc->n_blocked;
+	spin_unlock(&vc->lock);
+}
+
 extern int __kvmppc_vcore_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
+extern void xics_wake_cpu(int cpu);
 
-static int kvmppc_run_vcpu(struct kvm_run *run, struct kvm_vcpu *vcpu)
+static void kvmppc_remove_runnable(struct kvmppc_vcore *vc,
+				   struct kvm_vcpu *vcpu)
 {
-	u64 now;
+	struct kvm_vcpu *v;
 
-	if (signal_pending(current)) {
-		run->exit_reason = KVM_EXIT_INTR;
-		return -EINTR;
+	if (vcpu->arch.state != KVMPPC_VCPU_RUNNABLE)
+		return;
+	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
+	--vc->n_runnable;
+	/* decrement the physical thread id of each following vcpu */
+	v = vcpu;
+	list_for_each_entry_continue(v, &vc->runnable_threads, arch.run_list)
+		--v->arch.ptid;
+	list_del(&vcpu->arch.run_list);
+}
+
+static void kvmppc_start_thread(struct kvm_vcpu *vcpu)
+{
+	int cpu;
+	struct paca_struct *tpaca;
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+
+	cpu = vc->pcpu + vcpu->arch.ptid;
+	tpaca = &paca[cpu];
+	tpaca->kvm_hstate.kvm_vcpu = vcpu;
+	tpaca->kvm_hstate.kvm_vcore = vc;
+	smp_wmb();
+#ifdef CONFIG_PPC_ICP_NATIVE
+	if (vcpu->arch.ptid) {
+		tpaca->cpu_start = 0x80;
+		tpaca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST;
+		wmb();
+		xics_wake_cpu(cpu);
+		++vc->n_woken;
 	}
+#endif
+}
 
-	flush_fp_to_thread(current);
-	flush_altivec_to_thread(current);
-	flush_vsx_to_thread(current);
-	preempt_disable();
+static void kvmppc_wait_for_nap(struct kvmppc_vcore *vc)
+{
+	int i;
+
+	HMT_low();
+	i = 0;
+	while (vc->nap_count < vc->n_woken) {
+		if (++i >= 1000000) {
+			pr_err("kvmppc_wait_for_nap timeout %d %d\n",
+			       vc->nap_count, vc->n_woken);
+			break;
+		}
+		cpu_relax();
+	}
+	HMT_medium();
+}
+
+/*
+ * Check that we are on thread 0 and that any other threads in
+ * this core are off-line.
+ */
+static int on_primary_thread(void)
+{
+	int cpu = smp_processor_id();
+	int thr = cpu_thread_in_core(cpu);
+
+	if (thr)
+		return 0;
+	while (++thr < threads_per_core)
+		if (cpu_online(cpu + thr))
+			return 0;
+	return 1;
+}
+
+/*
+ * Run a set of guest threads on a physical core.
+ * Called with vc->lock held.
+ */
+static int kvmppc_run_core(struct kvmppc_vcore *vc)
+{
+	struct kvm_vcpu *vcpu, *vnext;
+	long ret;
+	u64 now;
+
+	/* don't start if any threads have a signal pending */
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+		if (signal_pending(vcpu->arch.run_task))
+			return 0;
 
 	/*
 	 * Make sure we are running on thread 0, and that
@@ -490,36 +638,150 @@ static int kvmppc_run_vcpu(struct kvm_run *run, struct kvm_vcpu *vcpu)
 	 * XXX we should also block attempts to bring any
 	 * secondary threads online.
 	 */
-	if (threads_per_core > 1) {
-		int cpu = smp_processor_id();
-		int thr = cpu_thread_in_core(cpu);
-
-		if (thr)
-			goto out;
-		while (++thr < threads_per_core)
-			if (cpu_online(cpu + thr))
-				goto out;
+	if (threads_per_core > 1 && !on_primary_thread()) {
+		list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+			vcpu->arch.ret = -EBUSY;
+		goto out;
 	}
 
-	kvm_guest_enter();
+	vc->n_woken = 0;
+	vc->nap_count = 0;
+	vc->entry_exit_count = 0;
+	vc->vcore_running = 1;
+	vc->in_guest = 0;
+	vc->pcpu = smp_processor_id();
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+		kvmppc_start_thread(vcpu);
+	vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
+				arch.run_list);
+
+	spin_unlock(&vc->lock);
 
+	preempt_disable();
+	kvm_guest_enter();
 	__kvmppc_vcore_entry(NULL, vcpu);
 
+	/* wait for secondary threads to finish writing their state to memory */
+	spin_lock(&vc->lock);
+	if (vc->nap_count < vc->n_woken)
+		kvmppc_wait_for_nap(vc);
+	/* prevent other vcpu threads from doing kvmppc_start_thread() now */
+	vc->vcore_running = 2;
+	spin_unlock(&vc->lock);
+
+	/* make sure updates to secondary vcpu structs are visible now */
+	smp_mb();
 	kvm_guest_exit();
 
 	preempt_enable();
 	kvm_resched(vcpu);
 
 	now = get_tb();
-	/* cancel pending dec exception if dec is positive */
-	if (now < vcpu->arch.dec_expires && kvmppc_core_pending_dec(vcpu))
-		kvmppc_core_dequeue_dec(vcpu);
-
-	return kvmppc_handle_exit(run, vcpu, current);
+	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
+		/* cancel pending dec exception if dec is positive */
+		if (now < vcpu->arch.dec_expires &&
+		    kvmppc_core_pending_dec(vcpu))
+			kvmppc_core_dequeue_dec(vcpu);
+		if (!vcpu->arch.trap) {
+			if (signal_pending(vcpu->arch.run_task)) {
+				vcpu->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
+				vcpu->arch.ret = -EINTR;
+			}
+			continue;		/* didn't get to run */
+		}
+		ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
+					 vcpu->arch.run_task);
+		vcpu->arch.ret = ret;
+		vcpu->arch.trap = 0;
+	}
 
+	spin_lock(&vc->lock);
  out:
-	preempt_enable();
-	return -EBUSY;
+	vc->vcore_running = 0;
+	list_for_each_entry_safe(vcpu, vnext, &vc->runnable_threads,
+				 arch.run_list) {
+		if (vcpu->arch.ret != RESUME_GUEST) {
+			kvmppc_remove_runnable(vc, vcpu);
+			wake_up(&vcpu->arch.cpu_run);
+		}
+	}
+
+	return 1;
+}
+
+static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
+{
+	int ptid;
+	int wait_state;
+	struct kvmppc_vcore *vc;
+	DEFINE_WAIT(wait);
+
+	/* No need to go into the guest when all we do is going out */
+	if (signal_pending(current)) {
+		kvm_run->exit_reason = KVM_EXIT_INTR;
+		return -EINTR;
+	}
+
+	kvm_run->exit_reason = 0;
+	vcpu->arch.ret = RESUME_GUEST;
+	vcpu->arch.trap = 0;
+
+	flush_fp_to_thread(current);
+	flush_altivec_to_thread(current);
+	flush_vsx_to_thread(current);
+
+	/*
+	 * Synchronize with other threads in this virtual core
+	 */
+	vc = vcpu->arch.vcore;
+	spin_lock(&vc->lock);
+	/* This happens the first time this is called for a vcpu */
+	if (vcpu->arch.state == KVMPPC_VCPU_BLOCKED)
+		--vc->n_blocked;
+	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
+	ptid = vc->n_runnable;
+	vcpu->arch.run_task = current;
+	vcpu->arch.kvm_run = kvm_run;
+	vcpu->arch.ptid = ptid;
+	list_add_tail(&vcpu->arch.run_list, &vc->runnable_threads);
+	++vc->n_runnable;
+
+	wait_state = TASK_INTERRUPTIBLE;
+	while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
+		if (signal_pending(current)) {
+			if (!vc->vcore_running) {
+				kvm_run->exit_reason = KVM_EXIT_INTR;
+				vcpu->arch.ret = -EINTR;
+				break;
+			}
+			/* have to wait for vcore to stop executing guest */
+			wait_state = TASK_UNINTERRUPTIBLE;
+			smp_send_reschedule(vc->pcpu);
+		}
+
+		if (!vc->vcore_running &&
+		    vc->n_runnable + vc->n_blocked == vc->num_threads) {
+			/* we can run now */
+			if (kvmppc_run_core(vc))
+				continue;
+		}
+
+		if (vc->vcore_running == 1 && VCORE_EXIT_COUNT(vc) == 0)
+			kvmppc_start_thread(vcpu);
+
+		/* wait for other threads to come in, or wait for vcore */
+		prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
+		spin_unlock(&vc->lock);
+		schedule();
+		finish_wait(&vcpu->arch.cpu_run, &wait);
+		spin_lock(&vc->lock);
+	}
+
+	if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE)
+		kvmppc_remove_runnable(vc, vcpu);
+	spin_unlock(&vc->lock);
+
+	return vcpu->arch.ret;
 }
 
 int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index e6adaad..c9bf177 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -30,8 +30,6 @@
  *                                                                           *
  ****************************************************************************/
 
-#define SHADOW_VCPU_OFF		PACA_KVM_SVCPU
-
 	.globl	kvmppc_skip_interrupt
 kvmppc_skip_interrupt:
 	mfspr	r13,SPRN_SRR0
@@ -79,6 +77,32 @@ _GLOBAL(kvmppc_hv_entry_trampoline)
  *                                                                            *
  *****************************************************************************/
 
+#define XICS_XIRR		4
+#define XICS_QIRR		0xc
+
+/*
+ * We come in here when wakened from nap mode on a secondary hw thread.
+ * Relocation is off and most register values are lost.
+ * r13 points to the PACA.
+ */
+	.globl	kvm_start_guest
+kvm_start_guest:
+	ld	r1,PACAEMERGSP(r13)
+	subi	r1,r1,STACK_FRAME_OVERHEAD
+
+	/* get vcpu pointer */
+	ld	r4, HSTATE_KVM_VCPU(r13)
+
+	/* We got here with an IPI; clear it */
+	ld	r5, HSTATE_XICS_PHYS(r13)
+	li	r0, 0xff
+	li	r6, XICS_QIRR
+	li	r7, XICS_XIRR
+	lwzcix	r8, r5, r7		/* ack the interrupt */
+	sync
+	stbcix	r0, r5, r6		/* clear it */
+	stwcix	r8, r5, r7		/* EOI it */
+
 .global kvmppc_hv_entry
 kvmppc_hv_entry:
 
@@ -200,7 +224,20 @@ kvmppc_hv_entry:
 	slbia
 	ptesync
 
-	/* Switch to guest partition. */
+	/* Increment entry count iff exit count is zero. */
+	ld	r5,HSTATE_KVM_VCORE(r13)
+	addi	r9,r5,VCORE_ENTRY_EXIT
+21:	lwarx	r3,0,r9
+	cmpwi	r3,0x100		/* any threads starting to exit? */
+	bge	secondary_too_late	/* if so we're too late to the party */
+	addi	r3,r3,1
+	stwcx.	r3,0,r9
+	bne	21b
+
+	/* Primary thread switches to guest partition. */
+	lwz	r6,VCPU_PTID(r4)
+	cmpwi	r6,0
+	bne	20f
 	ld	r9,VCPU_KVM(r4)		/* pointer to struct kvm */
 	ld	r6,KVM_SDR1(r9)
 	lwz	r7,KVM_LPID(r9)
@@ -210,7 +247,15 @@ kvmppc_hv_entry:
 	mtspr	SPRN_SDR1,r6		/* switch to partition page table */
 	mtspr	SPRN_LPID,r7
 	isync
-	ld	r8,VCPU_LPCR(r4)
+	li	r0,1
+	stb	r0,VCORE_IN_GUEST(r5)	/* signal secondaries to continue */
+	b	10f
+
+	/* Secondary threads wait for primary to have done partition switch */
+20:	lbz	r0,VCORE_IN_GUEST(r5)
+	cmpwi	r0,0
+	beq	20b
+10:	ld	r8,VCPU_LPCR(r4)
 	mtspr	SPRN_LPCR,r8
 	isync
 
@@ -225,10 +270,12 @@ kvmppc_hv_entry:
 	 * Invalidate the TLB if we could possibly have stale TLB
 	 * entries for this partition on this core due to the use
 	 * of tlbiel.
+	 * XXX maybe only need this on primary thread?
 	 */
 	ld	r9,VCPU_KVM(r4)		/* pointer to struct kvm */
 	lwz	r5,VCPU_VCPUID(r4)
 	lhz	r6,PACAPACAINDEX(r13)
+	rldimi	r6,r5,0,62		/* XXX map as if threads 1:1 p:v */
 	lhz	r8,VCPU_LAST_CPU(r4)
 	sldi	r7,r6,1			/* see if this is the same vcpu */
 	add	r7,r7,r9		/* as last ran on this pcpu */
@@ -512,8 +559,60 @@ hcall_real_cont:
 	ptesync
 
 hdec_soon:
-	/* Switch back to host partition */
+	/* Increment the threads-exiting-guest count in the 0xff00
+	   bits of vcore->entry_exit_count */
+	lwsync
+	ld	r5,HSTATE_KVM_VCORE(r13)
+	addi	r6,r5,VCORE_ENTRY_EXIT
+41:	lwarx	r3,0,r6
+	addi	r0,r3,0x100
+	stwcx.	r0,0,r6
+	bne	41b
+
+	/*
+	 * At this point we have an interrupt that we have to pass
+	 * up to the kernel or qemu; we can't handle it in real mode.
+	 * Thus we have to do a partition switch, so we have to
+	 * collect the other threads, if we are the first thread
+	 * to take an interrupt.  To do this, we set the HDEC to 0,
+	 * which causes an HDEC interrupt in all threads within 2ns
+	 * because the HDEC register is shared between all 4 threads.
+	 * However, we don't need to bother if this is an HDEC
+	 * interrupt, since the other threads will already be on their
+	 * way here in that case.
+	 */
+	cmpwi	r12,BOOK3S_INTERRUPT_HV_DECREMENTER
+	beq	40f
+	cmpwi	r3,0x100	/* Are we the first here? */
+	bge	40f
+	cmpwi	r3,1
+	ble	40f
+	li	r0,0
+	mtspr	SPRN_HDEC,r0
+40:
+
+	/* Secondary threads wait for primary to do partition switch */
 	ld	r4,VCPU_KVM(r9)		/* pointer to struct kvm */
+	ld	r5,HSTATE_KVM_VCORE(r13)
+	lwz	r3,VCPU_PTID(r9)
+	cmpwi	r3,0
+	beq	15f
+	HMT_LOW
+13:	lbz	r3,VCORE_IN_GUEST(r5)
+	cmpwi	r3,0
+	bne	13b
+	HMT_MEDIUM
+	b	16f
+
+	/* Primary thread waits for all the secondaries to exit guest */
+15:	lwz	r3,VCORE_ENTRY_EXIT(r5)
+	srwi	r0,r3,8
+	clrldi	r3,r3,56
+	cmpw	r3,r0
+	bne	15b
+	isync
+
+	/* Primary thread switches back to host partition */
 	ld	r6,KVM_HOST_SDR1(r4)
 	lwz	r7,KVM_HOST_LPID(r4)
 	li	r8,LPID_RSVD		/* switch to reserved LPID */
@@ -522,10 +621,12 @@ hdec_soon:
 	mtspr	SPRN_SDR1,r6		/* switch to partition page table */
 	mtspr	SPRN_LPID,r7
 	isync
+	li	r0,0
+	stb	r0,VCORE_IN_GUEST(r5)
 	lis	r8,0x7fff		/* MAX_INT@h */
 	mtspr	SPRN_HDEC,r8
 
-	ld	r8,KVM_HOST_LPCR(r4)
+16:	ld	r8,KVM_HOST_LPCR(r4)
 	mtspr	SPRN_LPCR,r8
 	isync
 
@@ -634,6 +735,11 @@ hdec_soon:
 	mr	r3, r9
 	bl	.kvmppc_save_fp
 
+	/* Secondary threads go off to take a nap */
+	lwz	r0,VCPU_PTID(r3)
+	cmpwi	r0,0
+	bne	secondary_nap
+
 	/*
 	 * Reload DEC.  HDEC interrupts were disabled when
 	 * we reloaded the host's LPCR value.
@@ -840,6 +946,56 @@ _GLOBAL(kvmppc_h_set_dabr)
 	li	r3,0
 	blr
 
+secondary_too_late:
+	ld	r5,HSTATE_KVM_VCORE(r13)
+	HMT_LOW
+13:	lbz	r3,VCORE_IN_GUEST(r5)
+	cmpwi	r3,0
+	bne	13b
+	HMT_MEDIUM
+	ld	r11,PACA_SLBSHADOWPTR(r13)
+
+	.rept	SLB_NUM_BOLTED
+	ld	r5,SLBSHADOW_SAVEAREA(r11)
+	ld	r6,SLBSHADOW_SAVEAREA+8(r11)
+	andis.	r7,r5,SLB_ESID_V@h
+	beq	1f
+	slbmte	r6,r5
+1:	addi	r11,r11,16
+	.endr
+	b	50f
+
+secondary_nap:
+	/* Clear any pending IPI */
+50:	ld	r5, HSTATE_XICS_PHYS(r13)
+	li	r0, 0xff
+	li	r6, XICS_QIRR
+	stbcix	r0, r5, r6
+
+	/* increment the nap count and then go to nap mode */
+	ld	r4, HSTATE_KVM_VCORE(r13)
+	addi	r4, r4, VCORE_NAP_COUNT
+	lwsync				/* make previous updates visible */
+51:	lwarx	r3, 0, r4
+	addi	r3, r3, 1
+	stwcx.	r3, 0, r4
+	bne	51b
+	isync
+
+	mfspr	r4, SPRN_LPCR
+	li	r0, LPCR_PECE
+	andc	r4, r4, r0
+	ori	r4, r4, LPCR_PECE0	/* exit nap on interrupt */
+	mtspr	SPRN_LPCR, r4
+	li	r0, 0
+	std	r0, HSTATE_SCRATCH0(r13)
+	ptesync
+	ld	r0, HSTATE_SCRATCH0(r13)
+1:	cmpd	r0, r0
+	bne	1b
+	nap
+	b	.
+
 /*
  * Save away FP, VMX and VSX registers.
  * r3 = vcpu pointer
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index c78ceb9..4c54966 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -30,6 +30,7 @@
 #include <asm/uaccess.h>
 #include <asm/kvm_ppc.h>
 #include <asm/tlbflush.h>
+#include <asm/cputhreads.h>
 #include "timing.h"
 #include "../mm/mmu_decl.h"
 
@@ -207,6 +208,9 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_SPAPR_TCE:
 		r = 1;
 		break;
+	case KVM_CAP_PPC_SMT:
+		r = threads_per_core;
+		break;
 #endif
 	default:
 		r = 0;
diff --git a/arch/powerpc/sysdev/xics/icp-native.c b/arch/powerpc/sysdev/xics/icp-native.c
index 1f15ad4..ba382b5 100644
--- a/arch/powerpc/sysdev/xics/icp-native.c
+++ b/arch/powerpc/sysdev/xics/icp-native.c
@@ -17,6 +17,7 @@
 #include <linux/cpu.h>
 #include <linux/of.h>
 #include <linux/spinlock.h>
+#include <linux/module.h>
 
 #include <asm/prom.h>
 #include <asm/io.h>
@@ -24,6 +25,7 @@
 #include <asm/irq.h>
 #include <asm/errno.h>
 #include <asm/xics.h>
+#include <asm/kvm_ppc.h>
 
 struct icp_ipl {
 	union {
@@ -139,6 +141,12 @@ static void icp_native_cause_ipi(int cpu, unsigned long data)
 	icp_native_set_qirr(cpu, IPI_PRIORITY);
 }
 
+void xics_wake_cpu(int cpu)
+{
+	icp_native_set_qirr(cpu, IPI_PRIORITY);
+}
+EXPORT_SYMBOL_GPL(xics_wake_cpu);
+
 static irqreturn_t icp_native_ipi_action(int irq, void *dev_id)
 {
 	int cpu = smp_processor_id();
@@ -185,6 +193,7 @@ static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr,
 	}
 
 	icp_native_regs[cpu] = ioremap(addr, size);
+	kvmppc_set_xics_phys(cpu, addr);
 	if (!icp_native_regs[cpu]) {
 		pr_warning("icp_native: Failed ioremap for CPU %d, "
 			   "interrupt server #0x%x, addr %#lx\n",
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 61f5650..e2a378d 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -551,6 +551,7 @@ struct kvm_ppc_pvinfo {
 #define KVM_CAP_GET_TSC_KHZ 61
 #define KVM_CAP_PPC_BOOKE_SREGS 62
 #define KVM_CAP_SPAPR_TCE 63
+#define KVM_CAP_PPC_SMT 64
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
