KVM/PPC/Book3S HV: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: kvm-ppc@vger.kernel.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: rt@linutronix.de
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alexander Graf <agraf@suse.com>
Link: http://lkml.kernel.org/r/20161126231350.10321-18-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3686471be32bd1a8e987c85dea958e553625fec2..39ef1f4a7b029e3fd171c87045cf81e4d868cb9a 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2254,12 +2254,12 @@ static void post_guest_process(struct kvmppc_vcore *vc, bool is_master)
  * enter the guest. Only do this if it is the primary thread of the
  * core (not if a subcore) that is entering the guest.
  */
-static inline void kvmppc_clear_host_core(int cpu)
+static inline int kvmppc_clear_host_core(unsigned int cpu)
 {
        int core;
 
        if (!kvmppc_host_rm_ops_hv || cpu_thread_in_core(cpu))
-               return;
+               return 0;
        /*
         * Memory barrier can be omitted here as we will do a smp_wmb()
         * later in kvmppc_start_thread and we need ensure that state is
@@ -2267,6 +2267,7 @@ static inline void kvmppc_clear_host_core(int cpu)
         */
        core = cpu >> threads_shift;
        kvmppc_host_rm_ops_hv->rm_core[core].rm_state.in_host = 0;
+       return 0;
 }
 
 /*
@@ -2274,12 +2275,12 @@ static inline void kvmppc_clear_host_core(int cpu)
  * Only need to do this if it is the primary thread of the core that is
  * exiting.
  */
-static inline void kvmppc_set_host_core(int cpu)
+static inline int kvmppc_set_host_core(unsigned int cpu)
 {
        int core;
 
        if (!kvmppc_host_rm_ops_hv || cpu_thread_in_core(cpu))
-               return;
+               return 0;
 
        /*
         * Memory barrier can be omitted here because we do a spin_unlock
@@ -2287,6 +2288,7 @@ static inline void kvmppc_set_host_core(int cpu)
         */
        core = cpu >> threads_shift;
        kvmppc_host_rm_ops_hv->rm_core[core].rm_state.in_host = 1;
+       return 0;
 }
 
 /*
@@ -3094,36 +3096,6 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 }
 
 #ifdef CONFIG_KVM_XICS
-static int kvmppc_cpu_notify(struct notifier_block *self, unsigned long action,
-                       void *hcpu)
-{
-       unsigned long cpu = (long)hcpu;
-
-       switch (action) {
-       case CPU_UP_PREPARE:
-       case CPU_UP_PREPARE_FROZEN:
-               kvmppc_set_host_core(cpu);
-               break;
-
-#ifdef CONFIG_HOTPLUG_CPU
-       case CPU_DEAD:
-       case CPU_DEAD_FROZEN:
-       case CPU_UP_CANCELED:
-       case CPU_UP_CANCELED_FROZEN:
-               kvmppc_clear_host_core(cpu);
-               break;
-#endif
-       default:
-               break;
-       }
-
-       return NOTIFY_OK;
-}
-
-static struct notifier_block kvmppc_cpu_notifier = {
-           .notifier_call = kvmppc_cpu_notify,
-};
-
 /*
  * Allocate a per-core structure for managing state about which cores are
  * running in the host versus the guest and for exchanging data between
@@ -3185,15 +3157,17 @@ void kvmppc_alloc_host_rm_ops(void)
                return;
        }
 
-       register_cpu_notifier(&kvmppc_cpu_notifier);
-
+       cpuhp_setup_state_nocalls(CPUHP_KVM_PPC_BOOK3S_PREPARE,
+                                 "ppc/kvm_book3s:prepare",
+                                 kvmppc_set_host_core,
+                                 kvmppc_clear_host_core);
        put_online_cpus();
 }
 
 void kvmppc_free_host_rm_ops(void)
 {
        if (kvmppc_host_rm_ops_hv) {
-               unregister_cpu_notifier(&kvmppc_cpu_notifier);
+               cpuhp_remove_state_nocalls(CPUHP_KVM_PPC_BOOK3S_PREPARE);
                kfree(kvmppc_host_rm_ops_hv->rm_core);
                kfree(kvmppc_host_rm_ops_hv);
                kvmppc_host_rm_ops_hv = NULL;

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 853f8176594d95d7f7c1cc9dbc0593e219cc240f..71c6822dd5be115322dde8571dbadbe5566c0387 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -68,6 +68,7 @@ enum cpuhp_state {
        CPUHP_MM_ZS_PREPARE,
        CPUHP_MM_ZSWP_MEM_PREPARE,
        CPUHP_MM_ZSWP_POOL_PREPARE,
+       CPUHP_KVM_PPC_BOOK3S_PREPARE,
        CPUHP_TIMERS_DEAD,
        CPUHP_NOTF_ERR_INJ_PREPARE,
        CPUHP_MIPS_SOC_PREPARE,