Re: [PATCH 14/17] ARM: Implement vcpu_kick()

[Julien Grall <julien.grall@arm.com>]

Hi Andre,

On 09/03/18 15:11, Andre Przywara wrote:
> If we change something in a vCPU that affects its runnability or
> otherwise needs the vCPU's attention, we might need to tell the scheduler
> about it.
> We are using this in one place (vIRQ injection) at the moment, but will
> need this at more places soon.
> So let's factor out this functionality, using the already existing
> vcpu_kick() prototype (used in x86 only so far), to make this available
> to the rest of the Xen code.
> 
> Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
> ---
> - Rename to vcpu_kick(), to blend in with existing (x86) prototype
> 
>   xen/arch/arm/domain.c | 12 ++++++++++++
>   xen/arch/arm/vgic.c   | 11 +++--------
>   2 files changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> index bc10f412ba..650712e0f2 100644
> --- a/xen/arch/arm/domain.c
> +++ b/xen/arch/arm/domain.c
> @@ -967,6 +967,18 @@ void vcpu_block_unless_event_pending(struct vcpu *v)
>           vcpu_unblock(current);
>   }
>   
> +void vcpu_kick(struct vcpu *vcpu)
> +{
> +    bool running = vcpu->is_running;
> +
> +    vcpu_unblock(vcpu);
> +    if ( running && vcpu != current )
> +    {
> +        perfc_incr(vgic_cross_cpu_intr_inject);

Sorry, it looks like I forgot to mention that in the previous version. 
The perfcounter should at least be renamed to match the new function.

> +        smp_send_event_check_mask(cpumask_of(vcpu->processor));
> +    }
> +}
> +
>   /*
>    * Local variables:
>    * mode: C
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index eb09d9ca54..3fafdd0b66 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -26,6 +26,7 @@
>   #include <xen/sched.h>
>   #include <xen/perfc.h>
>   
> +#include <asm/event.h>
>   #include <asm/current.h>
>   
>   #include <asm/mmio.h>
> @@ -530,7 +531,6 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq,
>       uint8_t priority;
>       struct pending_irq *iter, *n;
>       unsigned long flags;
> -    bool running;
>   
>       /*
>        * For edge triggered interrupts we always ignore a "falling edge".
> @@ -590,14 +590,9 @@ void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq,
>       list_add_tail(&n->inflight, &v->arch.vgic.inflight_irqs);
>   out:
>       spin_unlock_irqrestore(&v->arch.vgic.lock, flags);
> +
>       /* we have a new higher priority irq, inject it into the guest */
> -    running = v->is_running;
> -    vcpu_unblock(v);
> -    if ( running && v != current )
> -    {
> -        perfc_incr(vgic_cross_cpu_intr_inject);
> -        smp_send_event_check_mask(cpumask_of(v->processor));
> -    }
> +    vcpu_kick(v);
>   
>       return;
>   }
> 

Cheers,

-- 
Julien Grall

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