Re: [PATCH v9 05/10] xen/arm: physical irq follow virtual irq

[Julien Grall <julien.grall@linaro.org>]

On 07/28/2014 05:20 PM, Stefano Stabellini wrote:
> On Mon, 28 Jul 2014, Julien Grall wrote:
>> Hi stefano,
>>
>> On 07/24/2014 06:33 PM, Stefano Stabellini wrote:
>>> +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++ )
>>
>> Sorry, I didn't spot this error until now.
>>
>> For the VGIC nr_lines contains the number of *SPIs* rather on the GIC
>> structure it's the number of IRQs... the name is very confusing. I have
>> a patch to rename nr_lines into nr_spis, along with adding a macro
>> vgic_number_lines.
> 
> I couldn't parse this sentence.

Sorry it was not very clear.

> I guess you are saying that vgic.nr_lines doesn't represent the number
> of spis?

Yes. In the VGIC structure nr_lines = number of SPIs.

On GIC structure nr_lines = number of IRQs.

>> I plan to send it which my device passthrough patch series. As the patch
>> may help you. It may be better if you carry the patch.
> 
> Please append it here so I can have a look.

commit 534bdbbbd65b10f2780898bda2db5cdfc892dc34
Author: Julien Grall <julien.grall@linaro.org>
Date:   Fri Jul 18 12:25:18 2014 +0100

    xen/arm: vgic: Rename nr_lines into nr_spis
    
    The field nr_lines in the arch_domain vgic structure contains the number of
    SPIs for the emulated GIC. Using the nr_lines make confusion with the GIC
    code, where it means the number of IRQs. This can lead to coding error.
    
    Also introduce vgic_nr_lines to get the number of IRQ handled by the emulated
    GIC.
    
    Signed-off-by: Julien Grall <julien.grall@linaro.org>

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 19b2167..ee4f6ca 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -432,8 +432,6 @@ static int gicv2v_setup(struct domain *d)
         d->arch.vgic.cbase = GUEST_GICC_BASE;
     }
 
-    d->arch.vgic.nr_lines = 0;
-
     /*
      * Map the gic virtual cpu interface in the gic cpu interface
      * region of the guest.
diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index ae31dbf..fbda349 100644
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -54,7 +54,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         /* No secure world support for guests. */
         vgic_lock(v);
         *r = ( (v->domain->max_vcpus << 5) & GICD_TYPE_CPUS )
-            |( ((v->domain->arch.vgic.nr_lines / 32)) & GICD_TYPE_LINES );
+            |( ((v->domain->arch.vgic.nr_spis / 32)) & GICD_TYPE_LINES );
         vgic_unlock(v);
         return 1;
     case GICD_IIDR:
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 9f7ed4d..3204131 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -59,13 +59,10 @@ int domain_vgic_init(struct domain *d)

 
     d->arch.vgic.ctlr = 0;
 
-    /* Currently nr_lines in vgic and gic doesn't have the same meanings
-     * Here nr_lines = number of SPIs
-     */
     if ( is_hardware_domain(d) )
-        d->arch.vgic.nr_lines = gic_number_lines() - 32;
+        d->arch.vgic.nr_spis = gic_number_lines() - 32;
     else
-        d->arch.vgic.nr_lines = 0; /* We don't need SPIs for the guest */
+        d->arch.vgic.nr_spis = 0; /* We don't need SPIs for the guest */
 
     switch ( gic_hw_version() )
     {
@@ -83,11 +80,11 @@ int domain_vgic_init(struct domain *d)
         return -ENOMEM;
 
     d->arch.vgic.pending_irqs =
-        xzalloc_array(struct pending_irq, d->arch.vgic.nr_lines);
+        xzalloc_array(struct pending_irq, d->arch.vgic.nr_spis);
     if ( d->arch.vgic.pending_irqs == NULL )
         return -ENOMEM;
 
-    for (i=0; i<d->arch.vgic.nr_lines; i++)
+    for (i=0; i<d->arch.vgic.nr_spis; i++)
     {
         INIT_LIST_HEAD(&d->arch.vgic.pending_irqs[i].inflight);
         INIT_LIST_HEAD(&d->arch.vgic.pending_irqs[i].lr_queue);
@@ -230,7 +227,7 @@ void arch_move_irqs(struct vcpu *v)
     struct vcpu *v_target;
     int i;
 
-    for ( i = 32; i < d->arch.vgic.nr_lines; i++ )
+    for ( i = 32; i < d->arch.vgic.nr_spis; i++ )
     {
         v_target = vgic_get_target_vcpu(v, i);
         p = irq_to_pending(v_target, i);
@@ -354,7 +351,7 @@ int vgic_to_sgi(struct vcpu *v, register_t sgir, enum gic_sgi_mode irqmode, int
 struct pending_irq *irq_to_pending(struct vcpu *v, unsigned int irq)
 {
     struct pending_irq *n;
-    /* Pending irqs allocation strategy: the first vgic.nr_lines irqs
+    /* Pending irqs allocation strategy: the first vgic.nr_spis irqs
      * are used for SPIs; the rests are used for per cpu irqs */
     if ( irq < 32 )
         n = &v->arch.vgic.pending_irqs[irq];
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 32d0554..5719fe5 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -89,7 +89,7 @@ struct arch_domain
          */
         spinlock_t lock;
         int ctlr;
-        int nr_lines; /* Number of SPIs */
+        int nr_spis; /* Number of SPIs */
         struct vgic_irq_rank *shared_irqs;
         /*
          * SPIs are domain global, SGIs and PPIs are per-VCPU and stored in
diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
index 5d6a8ad..b94de8c 100644
--- a/xen/include/asm-arm/vgic.h
+++ b/xen/include/asm-arm/vgic.h
@@ -101,7 +101,7 @@ struct vgic_ops {
 };
 
 /* Number of ranks of interrupt registers for a domain */
-#define DOMAIN_NR_RANKS(d) (((d)->arch.vgic.nr_lines+31)/32)
+#define DOMAIN_NR_RANKS(d) (((d)->arch.vgic.nr_spis+31)/32)
 
 #define vgic_lock(v)   spin_lock_irq(&(v)->domain->arch.vgic.lock)
 #define vgic_unlock(v) spin_unlock_irq(&(v)->domain->arch.vgic.lock)
@@ -155,6 +155,8 @@ enum gic_sgi_mode;
  */
 #define REG_RANK_INDEX(b, n, s) ((((n) >> s) & ((b)-1)) % 32)
 
+#define vgic_num_irqs(d)        ((d)->arch.vgic.nr_spis + 32)
+
 extern int domain_vgic_init(struct domain *d);
 extern void domain_vgic_free(struct domain *d);
 extern int vcpu_vgic_init(struct vcpu *v);

Regards,


-- 
Julien Grall