Re: [PATCH v2 41/45] KVM: PPC: Move all vcpu init code into kvm_arch_vcpu_create()

From: Paolo Bonzini <pbonzini@redhat.com>
To: Paul Mackerras <paulus@ozlabs.org>,
	Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Marc Zyngier <maz@kernel.org>, James Hogan <jhogan@kernel.org>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	David Hildenbrand <david@redhat.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org,
	kvm-ppc@vger.kernel.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, Greg Kurz <groug@kaod.org>
Subject: Re: [PATCH v2 41/45] KVM: PPC: Move all vcpu init code into kvm_arch_vcpu_create()
Date: Tue, 21 Jan 2020 12:12:09 +0100	[thread overview]
Message-ID: <d3d465b0-6a45-c754-0538-1e4d1e130357@redhat.com> (raw)
In-Reply-To: <20200120034658.GD14307@blackberry>

On 20/01/20 04:46, Paul Mackerras wrote:
> On Wed, Dec 18, 2019 at 01:55:26PM -0800, Sean Christopherson wrote:
>> Fold init() into create() now that the two are called back-to-back by
>> common KVM code (kvm_vcpu_init() calls kvm_arch_vcpu_init() as its last
>> action, and kvm_vm_ioctl_create_vcpu() calls kvm_arch_vcpu_create()
>> immediately thereafter).  Rinse and repeat for kvm_arch_vcpu_uninit()
>> and kvm_arch_vcpu_destroy().  This paves the way for removing
>> kvm_arch_vcpu_{un}init() entirely.
>>
>> Note, calling kvmppc_mmu_destroy() if kvmppc_core_vcpu_create() fails
>> may or may not be necessary.  Move it along with the more obvious call
>> to kvmppc_subarch_vcpu_uninit() so as not to inadvertantly introduce a
>> functional change and/or bug.
>>
>> No functional change intended.
>>
>> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> 
> This doesn't compile.  I get:
> 
>   CC [M]  arch/powerpc/kvm/powerpc.o
> /home/paulus/kernel/kvm/arch/powerpc/kvm/powerpc.c: In function ‘kvm_arch_vcpu_create’:
> /home/paulus/kernel/kvm/arch/powerpc/kvm/powerpc.c:733:34: error: ‘kvmppc_decrementer_wakeup’ undeclared (first use in this function)
>   vcpu->arch.dec_timer.function = kvmppc_decrementer_wakeup;
>                                   ^
> /home/paulus/kernel/kvm/arch/powerpc/kvm/powerpc.c:733:34: note: each undeclared identifier is reported only once for each function it appears in
> /home/paulus/kernel/kvm/arch/powerpc/kvm/powerpc.c: At top level:
> /home/paulus/kernel/kvm/arch/powerpc/kvm/powerpc.c:794:29: warning: ‘kvmppc_decrementer_wakeup’ defined but not used [-Wunused-function]
>  static enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
>                              ^
> make[3]: *** [/home/paulus/kernel/kvm/scripts/Makefile.build:266: arch/powerpc/kvm/powerpc.o] Error 1
> 
> The problem is that kvmppc_decrementer_wakeup() is a static function
> defined in this file (arch/powerpc/kvm/powerpc.c) after
> kvm_arch_vcpu_create() but before kvm_arch_vcpu_init().  You need a
> forward static declaration of kvmppc_decrementer_wakeup() before
> kvm_arch_vcpu_create(), or else move one or other function.
> 
> Paul.
> 

Squashed:

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 91cf94d4191e..4fbf8690b8c5 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -725,6 +725,16 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 	return 0;
 }
 
+static enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
+{
+	struct kvm_vcpu *vcpu;
+
+	vcpu = container_of(timer, struct kvm_vcpu, arch.dec_timer);
+	kvmppc_decrementer_func(vcpu);
+
+	return HRTIMER_NORESTART;
+}
+
 int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 {
 	int err;
@@ -791,16 +801,6 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 	return kvmppc_core_pending_dec(vcpu);
 }
 
-static enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
-{
-	struct kvm_vcpu *vcpu;
-
-	vcpu = container_of(timer, struct kvm_vcpu, arch.dec_timer);
-	kvmppc_decrementer_func(vcpu);
-
-	return HRTIMER_NORESTART;
-}
-
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 {
 	return 0;

Paolo

