Re: [PATCH v5 4/5] KVM: irqfd: use kvm_arch_is_virtual_intc_initialized

From: Christoffer Dall
Date: Sun Jan 11 2015 - 16:17:24 EST


On Wed, Dec 03, 2014 at 05:07:11PM +0100, Eric Auger wrote:
> On arm/arm64, the interrupt controller is dynamically instantiated.
> There is a risk the user-space assigns an irqfd before this latter
> is initialized and ready to accept virtual irq injection. On such
> attempt, the IRQFD setup is rejected and -EAGAIN is returned.
>
> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
> ---
> virt/kvm/eventfd.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> index b0fb390..f837c83 100644
> --- a/virt/kvm/eventfd.c
> +++ b/virt/kvm/eventfd.c
> @@ -314,6 +314,9 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
> unsigned int events;
> int idx;
>
> + if (!kvm_arch_is_virtual_intc_initialized(kvm))
> + return -EAGAIN;
> +

You can fold this into the patch that defines the static inline since
nothing defines the KVM_HAVE_ARCH_... yet.

> irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
> if (!irqfd)
> return -ENOMEM;
> --
> 1.9.1
>
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