Re: [Xen-devel] [PATCH v2 02/45] ARM: Implement vcpu_kick()

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 15 Mar 2018, 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.
> Also adjust the perfcounter name to reflect the new usage.
> 
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
> Changelog v1 ... v2:
> - use vcpu_kick() name from x86 and existing prototype
> - rename performance counter
> 
>  xen/arch/arm/domain.c            | 12 ++++++++++++
>  xen/arch/arm/vgic.c              | 11 +++--------
>  xen/include/asm-arm/perfc_defn.h |  3 ++-
>  3 files changed, 17 insertions(+), 9 deletions(-)
> 
> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> index bc10f412ba..4462e62599 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(vcpu_kick);
> +        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;
>  }
> diff --git a/xen/include/asm-arm/perfc_defn.h 
> b/xen/include/asm-arm/perfc_defn.h
> index 87866264ca..8922e9525a 100644
> --- a/xen/include/asm-arm/perfc_defn.h
> +++ b/xen/include/asm-arm/perfc_defn.h
> @@ -33,6 +33,8 @@ PERFCOUNTER(vpsci_cpu_suspend,         "vpsci: cpu_suspend")
>  PERFCOUNTER(vpsci_cpu_affinity_info,   "vpsci: cpu_affinity_info")
>  PERFCOUNTER(vpsci_features,            "vpsci: features")
>  
> +PERFCOUNTER(vcpu_kick,                 "vcpu: notify other vcpu")
> +
>  PERFCOUNTER(vgicd_reads,                "vgicd: read")
>  PERFCOUNTER(vgicd_writes,               "vgicd: write")
>  PERFCOUNTER(vgicr_reads,                "vgicr: read")
> @@ -44,7 +46,6 @@ PERFCOUNTER(vgic_sysreg_writes,         "vgic: sysreg 
> write")
>  PERFCOUNTER(vgic_sgi_list  ,            "vgic: SGI send to list")
>  PERFCOUNTER(vgic_sgi_others,            "vgic: SGI send to others")
>  PERFCOUNTER(vgic_sgi_self,              "vgic: SGI send to self")
> -PERFCOUNTER(vgic_cross_cpu_intr_inject, "vgic: cross-CPU irq inject")
>  PERFCOUNTER(vgic_irq_migrates,          "vgic: irq migration")
>  
>  PERFCOUNTER(vuart_reads,  "vuart: read")
> -- 
> 2.14.1
> 

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