Re: [PATCH v5 5/6] xen/arm: support irq delivery to vcpu > 0

[Ian Campbell <Ian.Campbell@citrix.com>]

On Wed, 2014-06-11 at 17:27 +0100, Stefano Stabellini wrote:
> Use vgic_get_target_vcpu to retrieve the target vcpu from do_IRQ.
> Remove in-code comments about missing implementation of SGI delivery to
> vcpus other than 0.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> 
> ---
> 
> Changes in v4:
> - the mask in gic_route_irq_to_guest is a physical cpu mask, treat it as
> such;
> - export vgic_get_target_vcpu in a previous patch.
> ---
>  xen/arch/arm/gic.c        |    1 -
>  xen/arch/arm/irq.c        |    3 +--
>  xen/arch/arm/vgic.c       |    6 ++++++
>  xen/include/asm-arm/gic.h |    1 +
>  4 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
> index 8ed242e..82a0be4 100644
> --- a/xen/arch/arm/gic.c
> +++ b/xen/arch/arm/gic.c
> @@ -287,7 +287,6 @@ void gic_route_irq_to_guest(struct domain *d, struct irq_desc *desc,
>      gic_set_irq_properties(desc->irq, level, cpumask_of(smp_processor_id()),
>                             GIC_PRI_IRQ);
>  
> -    /* TODO: do not assume delivery to vcpu0 */

Replace with "Route to vcpu0 by default" ?

>      p = irq_to_pending(d->vcpu[0], desc->irq);
>      p->desc = desc;
>  }
> diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
> index a33c797..756250c 100644
> --- a/xen/arch/arm/irq.c
> +++ b/xen/arch/arm/irq.c
> @@ -175,8 +175,7 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq)
>          desc->status |= IRQ_INPROGRESS;
>          desc->arch.eoi_cpu = smp_processor_id();
>  
> -        /* XXX: inject irq into all guest vcpus */
> -        vgic_vcpu_inject_irq(d->vcpu[0], irq);
> +        vgic_vcpu_inject_spi(d, irq);

This needs an assert (or at least a comment) that the irq is not a PPI
because IRQ_GUEST is set and such things cannot be PPIs right now (and
that last subtlety needs a comment even with the assert)

>          goto out_no_end;
>      }
>  
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index e640de9..2192a8c 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -871,6 +871,12 @@ out:
>          smp_send_event_check_mask(cpumask_of(v->processor));
>  }
>  
> +void vgic_vcpu_inject_spi(struct domain *d, unsigned int irq)
> +{

Or maybe an ASSERT is needed here instead, or as well.

I'm almost inclined to suggest that vgic_get_target_vcpu should take
both d and v and that this caller should pass v==NULL and
vgic_get_target_vcpu should assert that IRQ is a SPI when v==NULL.

> +    struct vcpu *v = vgic_get_target_vcpu(d->vcpu[0], irq);
> +    vgic_vcpu_inject_irq(v, irq);
> +}
> +