2019-07-06 08:33:00

by Yi Wang

Subject: [PATCH] kvm: x86: Fix -Wmissing-prototypes warnings

We get a warning when build kernel W=1:

arch/x86/kvm/../../../virt/kvm/eventfd.c:48:1: warning: no previous prototype for ‘kvm_arch_irqfd_allowed’ [-Wmissing-prototypes]
kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
^

The reason is kvm_arch_irqfd_allowed is declared in arch/x86/kvm/irq.h,
which is not included by eventfd.c. Remove the declaration to kvm_host.h
can fix this.

Signed-off-by: Yi Wang <[email protected]>
---
arch/x86/kvm/irq.h | 1 -
include/linux/kvm_host.h | 1 +
2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index d6519a3..7c6233d 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -102,7 +102,6 @@ static inline int irqchip_in_kernel(struct kvm *kvm)
return mode != KVM_IRQCHIP_NONE;
}

-bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu);
void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu);
void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d1ad38a..5f04005 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -990,6 +990,7 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
int kvm_request_irq_source_id(struct kvm *kvm);
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
+bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);

/*
* search_memslots() and __gfn_to_memslot() are here because they are
--
1.8.3.1

2019-07-09 14:25:10

by Sean Christopherson

Subject: Re: [PATCH] kvm: x86: Fix -Wmissing-prototypes warnings

On Sat, Jul 06, 2019 at 04:29:50PM +0800, Yi Wang wrote:
> We get a warning when build kernel W=1:
>
> arch/x86/kvm/../../../virt/kvm/eventfd.c:48:1: warning: no previous prototype for ‘kvm_arch_irqfd_allowed’ [-Wmissing-prototypes]
> kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
> ^
>
> The reason is kvm_arch_irqfd_allowed is declared in arch/x86/kvm/irq.h,
> which is not included by eventfd.c. Remove the declaration to kvm_host.h
> can fix this.

It'd be nice to note in the changelog that kvm_arch_irqfd_allowed() is a
weakly defined function in eventfd.c. Without that info, one might wonder
why it's ok to move a function declaration from x86 code to generic code.

Reviewed-by: Sean Christopherson <[email protected]>

>
> Signed-off-by: Yi Wang <[email protected]>
> ---
> arch/x86/kvm/irq.h | 1 -
> include/linux/kvm_host.h | 1 +
> 2 files changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
> index d6519a3..7c6233d 100644
> --- a/arch/x86/kvm/irq.h
> +++ b/arch/x86/kvm/irq.h
> @@ -102,7 +102,6 @@ static inline int irqchip_in_kernel(struct kvm *kvm)
> return mode != KVM_IRQCHIP_NONE;
> }
>
> -bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
> void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu);
> void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu);
> void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu);
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index d1ad38a..5f04005 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -990,6 +990,7 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
> struct kvm_irq_ack_notifier *kian);
> int kvm_request_irq_source_id(struct kvm *kvm);
> void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
> +bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
>
> /*
> * search_memslots() and __gfn_to_memslot() are here because they are
> --
> 1.8.3.1
>