[patch V2 31/67] KVM/x86: Remove superfluous SMP function call

[patch V2 31/67] KVM/x86: Remove superfluous SMP function call

[Anna-Maria Gleixner]

[-- Attachment #1: 0030-KVM-x86-Remove-superfluous-SMP-function-call.patch --]
[-- Type: text/plain, Size: 1574 bytes --]

From: Anna-Maria Gleixner <anna-maria@linutronix.de>

Since the following commit:

  1cf4f629d9d2 ("cpu/hotplug: Move online calls to hotplugged cpu")

... the CPU_ONLINE and CPU_DOWN_PREPARE notifiers are always run on the hot
plugged CPU, and as of commit:

  3b9d6da67e11 ("cpu/hotplug: Fix rollback during error-out in __cpu_disable()")

the CPU_DOWN_FAILED notifier also runs on the hot plugged CPU.  This patch
converts the SMP functional calls into direct calls.

smp_function_call_single() executes the function with interrupts
disabled. This calling convention is not preserved because there
is no reason to do so.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
---
 arch/x86/kvm/x86.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5662,15 +5662,13 @@ static struct notifier_block kvmclock_cp
 static int kvmclock_cpu_notifier(struct notifier_block *nfb,
 					unsigned long action, void *hcpu)
 {
-	unsigned int cpu = (unsigned long)hcpu;
-
 	switch (action) {
 		case CPU_ONLINE:
 		case CPU_DOWN_FAILED:
-			smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
+			tsc_khz_changed(NULL);
 			break;
 		case CPU_DOWN_PREPARE:
-			smp_call_function_single(cpu, tsc_bad, NULL, 1);
+			tsc_bad(NULL);
 			break;
 	}
 	return NOTIFY_OK;

Re: [patch V2 31/67] KVM/x86: Remove superfluous SMP function call

[Paolo Bonzini]

On 13/07/2016 19:16, Anna-Maria Gleixner wrote:
> From: Anna-Maria Gleixner <anna-maria@linutronix.de>
> 
> Since the following commit:
> 
>   1cf4f629d9d2 ("cpu/hotplug: Move online calls to hotplugged cpu")
> 
> ... the CPU_ONLINE and CPU_DOWN_PREPARE notifiers are always run on the hot
> plugged CPU, and as of commit:
> 
>   3b9d6da67e11 ("cpu/hotplug: Fix rollback during error-out in __cpu_disable()")
> 
> the CPU_DOWN_FAILED notifier also runs on the hot plugged CPU.  This patch
> converts the SMP functional calls into direct calls.
> 
> smp_function_call_single() executes the function with interrupts
> disabled. This calling convention is not preserved because there
> is no reason to do so.
> 
> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Radim Krcmar <rkrcmar@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: kvm@vger.kernel.org
> ---
>  arch/x86/kvm/x86.c |    6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5662,15 +5662,13 @@ static struct notifier_block kvmclock_cp
>  static int kvmclock_cpu_notifier(struct notifier_block *nfb,
>  					unsigned long action, void *hcpu)
>  {
> -	unsigned int cpu = (unsigned long)hcpu;
> -
>  	switch (action) {
>  		case CPU_ONLINE:
>  		case CPU_DOWN_FAILED:
> -			smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
> +			tsc_khz_changed(NULL);
>  			break;
>  		case CPU_DOWN_PREPARE:
> -			smp_call_function_single(cpu, tsc_bad, NULL, 1);
> +			tsc_bad(NULL);
>  			break;
>  	}
>  	return NOTIFY_OK;
> 
> 

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

[patch V2 32/67] x86/kvm/kvmclock: Convert to hotplug state machine

[Anna-Maria Gleixner]

[-- Attachment #1: 0031-x86-kvm-kvmclock-Convert-to-hotplug-state-machine.patch --]
[-- Type: text/plain, Size: 3393 bytes --]

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

We assumed that the priority ordering was ment to invoke the online
callback as the last step. In the original code this also invoked the
down prepare callback as the last step. With the symmetric state
machine the down prepare callback is now the first step.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 arch/x86/kvm/x86.c         |   33 ++++++++-------------------------
 include/linux/cpuhotplug.h |    1 +
 2 files changed, 9 insertions(+), 25 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5552,9 +5552,10 @@ int kvm_fast_pio_out(struct kvm_vcpu *vc
 }
 EXPORT_SYMBOL_GPL(kvm_fast_pio_out);
 
-static void tsc_bad(void *info)
+static int kvmclock_cpu_down_prep(unsigned int cpu)
 {
 	__this_cpu_write(cpu_tsc_khz, 0);
+	return 0;
 }
 
 static void tsc_khz_changed(void *data)
@@ -5659,33 +5660,18 @@ static struct notifier_block kvmclock_cp
 	.notifier_call  = kvmclock_cpufreq_notifier
 };
 
-static int kvmclock_cpu_notifier(struct notifier_block *nfb,
-					unsigned long action, void *hcpu)
+static int kvmclock_cpu_online(unsigned int cpu)
 {
-	switch (action) {
-		case CPU_ONLINE:
-		case CPU_DOWN_FAILED:
-			tsc_khz_changed(NULL);
-			break;
-		case CPU_DOWN_PREPARE:
-			tsc_bad(NULL);
-			break;
-	}
-	return NOTIFY_OK;
+	tsc_khz_changed(NULL);
+	return 0;
 }
 
-static struct notifier_block kvmclock_cpu_notifier_block = {
-	.notifier_call  = kvmclock_cpu_notifier,
-	.priority = -INT_MAX
-};
-
 static void kvm_timer_init(void)
 {
 	int cpu;
 
 	max_tsc_khz = tsc_khz;
 
-	cpu_notifier_register_begin();
 	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
 #ifdef CONFIG_CPU_FREQ
 		struct cpufreq_policy policy;
@@ -5700,12 +5686,9 @@ static void kvm_timer_init(void)
 					  CPUFREQ_TRANSITION_NOTIFIER);
 	}
 	pr_debug("kvm: max_tsc_khz = %ld\n", max_tsc_khz);
-	for_each_online_cpu(cpu)
-		smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
-
-	__register_hotcpu_notifier(&kvmclock_cpu_notifier_block);
-	cpu_notifier_register_done();
 
+	cpuhp_setup_state(CPUHP_AP_X86_KVM_CLK_ONLINE, "AP_X86_KVM_CLK_ONLINE",
+			  kvmclock_cpu_online, kvmclock_cpu_down_prep);
 }
 
 static DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu);
@@ -5894,7 +5877,7 @@ void kvm_arch_exit(void)
 	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
 		cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block,
 					    CPUFREQ_TRANSITION_NOTIFIER);
-	unregister_hotcpu_notifier(&kvmclock_cpu_notifier_block);
+	cpuhp_remove_state_nocalls(CPUHP_AP_X86_KVM_CLK_ONLINE);
 #ifdef CONFIG_X86_64
 	pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier);
 #endif
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -57,6 +57,7 @@ enum cpuhp_state {
 	CPUHP_AP_ONLINE_DYN,
 	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,
 	CPUHP_AP_X86_HPET_ONLINE,
+	CPUHP_AP_X86_KVM_CLK_ONLINE,
 	CPUHP_AP_ACTIVE,
 	CPUHP_ONLINE,
 };

[patch V2 36/67] virt: Convert kvm hotplug to state machine

[Anna-Maria Gleixner]

[-- Attachment #1: 0035-virt-Convert-kvm-hotplug-to-state-machine.patch --]
[-- Type: text/plain, Size: 3813 bytes --]

From: Thomas Gleixner <tglx@linutronix.de>

Install the callbacks via the state machine. The core won't invoke the
callbacks on already online CPUs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 include/linux/cpuhotplug.h |  1 +
 virt/kvm/kvm_main.c        | 32 ++++++++------------------------
 2 files changed, 9 insertions(+), 24 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 365d615..1d71f38 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -37,6 +37,7 @@ enum cpuhp_state {
 	CPUHP_AP_PERF_XTENSA_STARTING,
 	CPUHP_AP_ARM_VFP_STARTING,
 	CPUHP_AP_PERF_ARM_STARTING,
+	CPUHP_AP_KVM_STARTING,
 	CPUHP_AP_NOTIFY_STARTING,
 	CPUHP_AP_ONLINE,
 	CPUHP_TEARDOWN_CPU,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 48bd520..c1d6cf5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3144,12 +3144,13 @@ static void hardware_enable_nolock(void *junk)
 	}
 }
 
-static void hardware_enable(void)
+static int kvm_starting_cpu(unsigned int cpu)
 {
 	raw_spin_lock(&kvm_count_lock);
 	if (kvm_usage_count)
 		hardware_enable_nolock(NULL);
 	raw_spin_unlock(&kvm_count_lock);
+	return 0;
 }
 
 static void hardware_disable_nolock(void *junk)
@@ -3162,12 +3163,13 @@ static void hardware_disable_nolock(void *junk)
 	kvm_arch_hardware_disable();
 }
 
-static void hardware_disable(void)
+static int kvm_dying_cpu(unsigned int cpu)
 {
 	raw_spin_lock(&kvm_count_lock);
 	if (kvm_usage_count)
 		hardware_disable_nolock(NULL);
 	raw_spin_unlock(&kvm_count_lock);
+	return 0;
 }
 
 static void hardware_disable_all_nolock(void)
@@ -3208,21 +3210,6 @@ static int hardware_enable_all(void)
 	return r;
 }
 
-static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
-			   void *v)
-{
-	val &= ~CPU_TASKS_FROZEN;
-	switch (val) {
-	case CPU_DYING:
-		hardware_disable();
-		break;
-	case CPU_STARTING:
-		hardware_enable();
-		break;
-	}
-	return NOTIFY_OK;
-}
-
 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
 		      void *v)
 {
@@ -3489,10 +3476,6 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
 	return r;
 }
 
-static struct notifier_block kvm_cpu_notifier = {
-	.notifier_call = kvm_cpu_hotplug,
-};
-
 static int kvm_debugfs_open(struct inode *inode, struct file *file,
 			   int (*get)(void *, u64 *), int (*set)(void *, u64),
 			   const char *fmt)
@@ -3743,7 +3726,8 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 			goto out_free_1;
 	}
 
-	r = register_cpu_notifier(&kvm_cpu_notifier);
+	r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "AP_KVM_STARTING",
+				      kvm_starting_cpu, kvm_dying_cpu);
 	if (r)
 		goto out_free_2;
 	register_reboot_notifier(&kvm_reboot_notifier);
@@ -3797,7 +3781,7 @@ out_free:
 	kmem_cache_destroy(kvm_vcpu_cache);
 out_free_3:
 	unregister_reboot_notifier(&kvm_reboot_notifier);
-	unregister_cpu_notifier(&kvm_cpu_notifier);
+	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
 out_free_2:
 out_free_1:
 	kvm_arch_hardware_unsetup();
@@ -3820,7 +3804,7 @@ void kvm_exit(void)
 	kvm_async_pf_deinit();
 	unregister_syscore_ops(&kvm_syscore_ops);
 	unregister_reboot_notifier(&kvm_reboot_notifier);
-	unregister_cpu_notifier(&kvm_cpu_notifier);
+	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
 	on_each_cpu(hardware_disable_nolock, NULL, 1);
 	kvm_arch_hardware_unsetup();
 	kvm_arch_exit();
-- 
2.8.1

[patch V2 44/67] arm/kvm/vgic: Convert to hotplug state machine

[Anna-Maria Gleixner]

[-- Attachment #1: 0043-arm-kvm-vgic-Convert-to-hotplug-state-machine.patch --]
[-- Type: text/plain, Size: 3027 bytes --]

From: Richard Cochran <rcochran@linutronix.de>

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
The VGIC callback is run after KVM's main callback since it reflects the
makefile order.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 include/linux/cpuhotplug.h |  1 +
 virt/kvm/arm/vgic.c        | 39 ++++++++-------------------------------
 2 files changed, 9 insertions(+), 31 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index ef7bfa6..80c15ce 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -43,6 +43,7 @@ enum cpuhp_state {
 	CPUHP_AP_QCOM_TIMER_STARTING,
 	CPUHP_AP_MIPS_GIC_TIMER_STARTING,
 	CPUHP_AP_KVM_STARTING,
+	CPUHP_AP_KVM_ARM_VGIC_STARTING,
 	CPUHP_AP_LEDTRIG_STARTING,
 	CPUHP_AP_NOTIFY_STARTING,
 	CPUHP_AP_ONLINE,
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index c3bfbb9..67cb5e9 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -2326,32 +2326,18 @@ int vgic_has_attr_regs(const struct vgic_io_range *ranges, phys_addr_t offset)
 		return -ENXIO;
 }
 
-static void vgic_init_maintenance_interrupt(void *info)
+static int vgic_starting_cpu(unsigned int cpu)
 {
 	enable_percpu_irq(vgic->maint_irq, 0);
+	return 0;
 }
 
-static int vgic_cpu_notify(struct notifier_block *self,
-			   unsigned long action, void *cpu)
+static int vgic_dying_cpu(unsigned int cpu)
 {
-	switch (action) {
-	case CPU_STARTING:
-	case CPU_STARTING_FROZEN:
-		vgic_init_maintenance_interrupt(NULL);
-		break;
-	case CPU_DYING:
-	case CPU_DYING_FROZEN:
-		disable_percpu_irq(vgic->maint_irq);
-		break;
-	}
-
-	return NOTIFY_OK;
+	disable_percpu_irq(vgic->maint_irq);
+	return 0;
 }
 
-static struct notifier_block vgic_cpu_nb = {
-	.notifier_call = vgic_cpu_notify,
-};
-
 static int kvm_vgic_probe(void)
 {
 	const struct gic_kvm_info *gic_kvm_info;
@@ -2392,19 +2378,10 @@ int kvm_vgic_hyp_init(void)
 		return ret;
 	}
 
-	ret = __register_cpu_notifier(&vgic_cpu_nb);
-	if (ret) {
-		kvm_err("Cannot register vgic CPU notifier\n");
-		goto out_free_irq;
-	}
-
-	on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
-
+	cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_STARTING,
+			  "AP_KVM_ARM_VGIC_STARTING", vgic_starting_cpu,
+			  vgic_dying_cpu);
 	return 0;
-
-out_free_irq:
-	free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus());
-	return ret;
 }
 
 int kvm_irq_map_gsi(struct kvm *kvm,
-- 
2.8.1

[patch V2 45/67] arm/kvm/arch_timer: Convert to hotplug state machine

[Anna-Maria Gleixner]

[-- Attachment #1: 0044-arm-kvm-arch_timer-Convert-to-hotplug-state-machine.patch --]
[-- Type: text/plain, Size: 2990 bytes --]

From: Richard Cochran <rcochran@linutronix.de>

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 include/linux/cpuhotplug.h |  1 +
 virt/kvm/arm/arch_timer.c  | 35 +++++++++++------------------------
 2 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 80c15ce..0a36e61 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -44,6 +44,7 @@ enum cpuhp_state {
 	CPUHP_AP_MIPS_GIC_TIMER_STARTING,
 	CPUHP_AP_KVM_STARTING,
 	CPUHP_AP_KVM_ARM_VGIC_STARTING,
+	CPUHP_AP_KVM_ARM_TIMER_STARTING,
 	CPUHP_AP_LEDTRIG_STARTING,
 	CPUHP_AP_NOTIFY_STARTING,
 	CPUHP_AP_ONLINE,
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index e2d5b6f..4fde8c7 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -405,26 +405,17 @@ u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)
 	return (u64)-1;
 }
 
-static int kvm_timer_cpu_notify(struct notifier_block *self,
-				unsigned long action, void *cpu)
+static int kvm_timer_starting_cpu(unsigned int cpu)
 {
-	switch (action) {
-	case CPU_STARTING:
-	case CPU_STARTING_FROZEN:
-		kvm_timer_init_interrupt(NULL);
-		break;
-	case CPU_DYING:
-	case CPU_DYING_FROZEN:
-		disable_percpu_irq(host_vtimer_irq);
-		break;
-	}
-
-	return NOTIFY_OK;
+	kvm_timer_init_interrupt(NULL);
+	return 0;
 }
 
-static struct notifier_block kvm_timer_cpu_nb = {
-	.notifier_call = kvm_timer_cpu_notify,
-};
+static int kvm_timer_dying_cpu(unsigned int cpu)
+{
+	disable_percpu_irq(host_vtimer_irq);
+	return 0;
+}
 
 int kvm_timer_hyp_init(void)
 {
@@ -449,12 +440,6 @@ int kvm_timer_hyp_init(void)
 		goto out;
 	}
 
-	err = __register_cpu_notifier(&kvm_timer_cpu_nb);
-	if (err) {
-		kvm_err("Cannot register timer CPU notifier\n");
-		goto out_free;
-	}
-
 	wqueue = create_singlethread_workqueue("kvm_arch_timer");
 	if (!wqueue) {
 		err = -ENOMEM;
@@ -462,8 +447,10 @@ int kvm_timer_hyp_init(void)
 	}
 
 	kvm_info("virtual timer IRQ%d\n", host_vtimer_irq);
-	on_each_cpu(kvm_timer_init_interrupt, NULL, 1);
 
+	cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING,
+			  "AP_KVM_ARM_TIMER_STARTING", kvm_timer_starting_cpu,
+			  kvm_timer_dying_cpu);
 	goto out;
 out_free:
 	free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus());
-- 
2.8.1

[patch V2 60/67] KVM/arm/arm64/vgic-new: Convert to hotplug state machine

[Anna-Maria Gleixner]

[-- Attachment #1: 0059-KVM-arm-arm64-vgic-new-Convert-to-hotplug-state-mach.patch --]
[-- Type: text/plain, Size: 2881 bytes --]

From: Anna-Maria Gleixner <anna-maria@linutronix.de>

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Eric Auger <eric.auger@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
---
 include/linux/cpuhotplug.h    |  1 +
 virt/kvm/arm/vgic/vgic-init.c | 31 +++++++++----------------------
 2 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 078bd22..822df54 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -52,6 +52,7 @@ enum cpuhp_state {
 	CPUHP_AP_QCOM_TIMER_STARTING,
 	CPUHP_AP_MIPS_GIC_TIMER_STARTING,
 	CPUHP_AP_KVM_STARTING,
+	CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
 	CPUHP_AP_KVM_ARM_VGIC_STARTING,
 	CPUHP_AP_KVM_ARM_TIMER_STARTING,
 	CPUHP_AP_ARM_XEN_STARTING,
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index a1442f7..2c7f0d5 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -353,32 +353,19 @@ out:
 
 /* GENERIC PROBE */
 
-static void vgic_init_maintenance_interrupt(void *info)
+static int vgic_init_cpu_starting(unsigned int cpu)
 {
 	enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
+	return 0;
 }
 
-static int vgic_cpu_notify(struct notifier_block *self,
-			   unsigned long action, void *cpu)
-{
-	switch (action) {
-	case CPU_STARTING:
-	case CPU_STARTING_FROZEN:
-		vgic_init_maintenance_interrupt(NULL);
-		break;
-	case CPU_DYING:
-	case CPU_DYING_FROZEN:
-		disable_percpu_irq(kvm_vgic_global_state.maint_irq);
-		break;
-	}
 
-	return NOTIFY_OK;
+static int vgic_init_cpu_dying(unsigned int cpu)
+{
+	disable_percpu_irq(kvm_vgic_global_state.maint_irq);
+	return 0;
 }
 
-static struct notifier_block vgic_cpu_nb = {
-	.notifier_call = vgic_cpu_notify,
-};
-
 static irqreturn_t vgic_maintenance_handler(int irq, void *data)
 {
 	/*
@@ -434,14 +421,14 @@ int kvm_vgic_hyp_init(void)
 		return ret;
 	}
 
-	ret = __register_cpu_notifier(&vgic_cpu_nb);
+	ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
+				"AP_KVM_ARM_VGIC_INIT_STARTING",
+				vgic_init_cpu_starting, vgic_init_cpu_dying);
 	if (ret) {
 		kvm_err("Cannot register vgic CPU notifier\n");
 		goto out_free_irq;
 	}
 
-	on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
-
 	kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
 	return 0;
 
-- 
2.8.1

Re: [patch V2 60/67] KVM/arm/arm64/vgic-new: Convert to hotplug state machine

[Marc Zyngier]

On 13/07/16 18:17, Anna-Maria Gleixner wrote:
> From: Anna-Maria Gleixner <anna-maria@linutronix.de>
> 
> Install the callbacks via the state machine and let the core invoke
> the callbacks on the already online CPUs.
> 
> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
> Cc: Andre Przywara <andre.przywara@arm.com>
> Cc: Christoffer Dall <christoffer.dall@linaro.org>
> Cc: Eric Auger <eric.auger@linaro.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Radim Krcmar <rkrcmar@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: kvm@vger.kernel.org
> Cc: kvmarm@lists.cs.columbia.edu
> Cc: linux-arm-kernel@lists.infradead.org

For patches 3, 4, 5, 6, 7, 44, 45 and 60:

Acked-by: Marc Zyngier <marc.zyngier@arm.com>

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...