[tip:smp/hotplug] KVM/PPC/Book3S HV: Convert to hotplug state machine

From: tip-bot for Anna-Maria Gleixner
Date: Thu Dec 01 2016 - 19:16:26 EST


Commit-ID: 3f7cd919f3df05918535de39273174710409eb40
Gitweb: http://git.kernel.org/tip/3f7cd919f3df05918535de39273174710409eb40
Author: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
AuthorDate: Sun, 27 Nov 2016 00:13:45 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 2 Dec 2016 00:52:38 +0100

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

Install the callbacks via the state machine.

Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: kvm-ppc@xxxxxxxxxxxxxxx
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: rt@xxxxxxxxxxxxx
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Alexander Graf <agraf@xxxxxxxx>
Link: http://lkml.kernel.org/r/20161126231350.10321-18-bigeasy@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
arch/powerpc/kvm/book3s_hv.c | 48 ++++++++++----------------------------------
include/linux/cpuhotplug.h | 1 +
2 files changed, 12 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3686471..39ef1f4 100644
--- 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 853f817..71c6822 100644
--- 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,