diff mbox

[Xen-devel,v6,4/5] xen/arm: physical irq follow virtual irq

Message ID 1403541463-23734-4-git-send-email-stefano.stabellini@eu.citrix.com
State New
Headers show

Commit Message

Stefano Stabellini June 23, 2014, 4:37 p.m. UTC 
Migrate physical irqs to the same physical cpu that is running the vcpu
expected to receive the irqs. That is done when enabling irqs, when the
guest writes to GICD_ITARGETSR and when Xen migrates a vcpu to a
different pcpu.

Introduce a new arch specific function, arch_move_irqs, that is empty on
x86 and implements the vgic irq migration code on ARM.
arch_move_irqs is going to be called by from sched.c.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

---

Changes in v6:
- use vgic_get_target_vcpu instead of _vgic_get_target_vcpu in
arch_move_irqs.

Changes in v5:
- prettify vgic_move_irqs;
- rename vgic_move_irqs to arch_move_irqs;
- introduce helper function irq_set_affinity.
---
 xen/arch/arm/gic.c        |   18 ++++++++++++++++--
 xen/arch/arm/vgic.c       |   30 ++++++++++++++++++++++++++++++
 xen/include/asm-arm/gic.h |    1 +
 xen/include/asm-x86/irq.h |    2 ++
 4 files changed, 49 insertions(+), 2 deletions(-)

Comments

Julien Grall June 24, 2014, 1:43 p.m. UTC | #1 
Hi Stefano,

On 06/23/2014 05:37 PM, Stefano Stabellini wrote:
> -static void gic_irq_set_affinity(struct irq_desc *desc, const cpumask_t *mask)
> +static void gic_irq_set_affinity(struct irq_desc *desc, const cpumask_t *cpu_mask)
>  {
> -    BUG();
> +    volatile unsigned char *bytereg;
> +    unsigned int mask;
> +
> +    if ( desc == NULL || cpumask_empty(cpu_mask) )
> +        return;

I think this check is pointless. Every irq_callback relies on the desc
is not NULL. Hence, you already check it in irq_set_affinity.

For the cpu_mask, we are in trouble is someone is calling with an empty
mask. I would replace it by an ASSERT.

The check here is pointless here. Every irq_callback rely on the desc is
not NULL. Why this

>  /* XXX different for level vs edge */
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index b2f922c..5a504ad 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -438,6 +438,32 @@ static void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int ir
>      spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
>  }
>  
> +static inline void irq_set_affinity(struct irq_desc *desc,
> +                                    const cpumask_t *cpu_mask)
> +{
> +    if ( desc != NULL )
> +        desc->handler->set_affinity(desc, cpu_mask);
> +}

This function belongs to the IRQ module. It might be useful for other
part in the future.

I would move this function in irq.c or in asm-arm/irq.h if you want to
keep it as inline function.

Regards,
Stefano Stabellini July 2, 2014, 6:14 p.m. UTC | #2 
On Tue, 24 Jun 2014, Julien Grall wrote:
> Hi Stefano,
> 
> On 06/23/2014 05:37 PM, Stefano Stabellini wrote:
> > -static void gic_irq_set_affinity(struct irq_desc *desc, const cpumask_t *mask)
> > +static void gic_irq_set_affinity(struct irq_desc *desc, const cpumask_t *cpu_mask)
> >  {
> > -    BUG();
> > +    volatile unsigned char *bytereg;
> > +    unsigned int mask;
> > +
> > +    if ( desc == NULL || cpumask_empty(cpu_mask) )
> > +        return;
> 
> I think this check is pointless. Every irq_callback relies on the desc
> is not NULL. Hence, you already check it in irq_set_affinity.
> 
> For the cpu_mask, we are in trouble is someone is calling with an empty
> mask. I would replace it by an ASSERT.

OK


> The check here is pointless here. Every irq_callback rely on the desc is
> not NULL. Why this
> 
> >  /* XXX different for level vs edge */
> > diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> > index b2f922c..5a504ad 100644
> > --- a/xen/arch/arm/vgic.c
> > +++ b/xen/arch/arm/vgic.c
> > @@ -438,6 +438,32 @@ static void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int ir
> >      spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
> >  }
> >  
> > +static inline void irq_set_affinity(struct irq_desc *desc,
> > +                                    const cpumask_t *cpu_mask)
> > +{
> > +    if ( desc != NULL )
> > +        desc->handler->set_affinity(desc, cpu_mask);
> > +}
> 
> This function belongs to the IRQ module. It might be useful for other
> part in the future.
> 
> I would move this function in irq.c or in asm-arm/irq.h if you want to
> keep it as inline function.

OK
diff mbox

Patch

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 54610ce..1965f86 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -192,9 +192,23 @@  static void gic_guest_irq_end(struct irq_desc *desc)
     /* Deactivation happens in maintenance interrupt / via GICV */
 }
 
-static void gic_irq_set_affinity(struct irq_desc *desc, const cpumask_t *mask)
+static void gic_irq_set_affinity(struct irq_desc *desc, const cpumask_t *cpu_mask)
 {
-    BUG();
+    volatile unsigned char *bytereg;
+    unsigned int mask;
+
+    if ( desc == NULL || cpumask_empty(cpu_mask) )
+        return;
+
+    spin_lock(&gic.lock);
+
+    mask = gic_cpu_mask(cpu_mask);
+
+    /* Set target CPU mask (RAZ/WI on uniprocessor) */
+    bytereg = (unsigned char *) (GICD + GICD_ITARGETSR);
+    bytereg[desc->irq] = mask;
+
+    spin_unlock(&gic.lock);
 }
 
 /* XXX different for level vs edge */
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index b2f922c..5a504ad 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -438,6 +438,32 @@  static void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int ir
     spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
 }
 
+static inline void irq_set_affinity(struct irq_desc *desc,
+                                    const cpumask_t *cpu_mask)
+{
+    if ( desc != NULL )
+        desc->handler->set_affinity(desc, cpu_mask);
+}
+
+void arch_move_irqs(struct vcpu *v)
+{
+    const cpumask_t *cpu_mask = cpumask_of(v->processor);
+    struct domain *d = v->domain;
+    struct pending_irq *p;
+    struct vcpu *v_target;
+    int i;
+
+    for ( i = 32; i < d->arch.vgic.nr_lines; i++ )
+    {
+        v_target = vgic_get_target_vcpu(v, i);
+        if ( v_target == v )
+        {
+            p = irq_to_pending(v, i);
+            irq_set_affinity(p->desc, cpu_mask);
+        }
+    }
+}
+
 static void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
 {
     const unsigned long mask = r;
@@ -493,6 +519,7 @@  static void vgic_enable_irqs(struct vcpu *v, uint32_t r, int n)
         }
         if ( p->desc != NULL )
         {
+            irq_set_affinity(p->desc, cpumask_of(v_target->processor));
             spin_lock_irqsave(&p->desc->lock, flags);
             p->desc->handler->enable(p->desc);
             spin_unlock_irqrestore(&p->desc->lock, flags);
@@ -681,6 +708,7 @@  static int vgic_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
             unsigned int irq, target, old_target;
             unsigned long old_target_mask;
             struct vcpu *v_target, *v_old;
+            struct pending_irq *p;
 
             target = i % 8;
             old_target_mask = byte_read(rank->itargets[REG_RANK_INDEX(8, gicd_reg - GICD_ITARGETSR)], 0, i/8);
@@ -692,6 +720,8 @@  static int vgic_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
                 v_target = v->domain->vcpu[target];
                 v_old = v->domain->vcpu[old_target];
                 vgic_migrate_irq(v_old, v_target, irq);
+                p = irq_to_pending(v_target, irq);
+                irq_set_affinity(p->desc, cpumask_of(v_target->processor));
             }
             i += 8 - target;
         }
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index ba9ba9b..dcc2f1c 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -228,6 +228,7 @@  int gic_irq_xlate(const u32 *intspec, unsigned int intsize,
 void gic_clear_lrs(struct vcpu *v);
 
 struct vcpu *vgic_get_target_vcpu(struct vcpu *v, unsigned int irq);
+void arch_move_irqs(struct vcpu *v);
 
 #endif /* __ASSEMBLY__ */
 #endif
diff --git a/xen/include/asm-x86/irq.h b/xen/include/asm-x86/irq.h
index 9066d38..d3c55f3 100644
--- a/xen/include/asm-x86/irq.h
+++ b/xen/include/asm-x86/irq.h
@@ -197,4 +197,6 @@  void cleanup_domain_irq_mapping(struct domain *);
 
 bool_t cpu_has_pending_apic_eoi(void);
 
+static inline void arch_move_irqs(struct vcpu *v) { }
+
 #endif /* _ASM_HW_IRQ_H */