[Xen-devel,09/17] ARM: VGIC: change to level-IRQ compatible IRQ injection interface

Message ID 20180309151133.31371-10-andre.przywara@linaro.org
State New
Headers show
Series
  • ARM: vGIC: prepare for splitting the vGIC code
Related show

Commit Message

Andre Przywara March 9, 2018, 3:11 p.m.
At the moment vgic_vcpu_inject_irq() is the interface for Xen internal
code and virtual devices to inject IRQs into a guest. This interface has
two shortcomings:
1) It requires a VCPU pointer, which we may not know (and don't need!)
for shared interrupts. A second function (vgic_vcpu_inject_spi()), was
there to work around this issue.
2) This interface only really supports edge triggered IRQs, which is
what the Xen VGIC emulates only anyway. However this needs to and will
change, so we need to add the desired level (high or low) to the
interface.
This replaces the existing injection call (taking a VCPU and an IRQ
parameter) with a new one, taking domain, VCPU, IRQ and level parameters.
The VCPU can be NULL in case we don't know and don't care.
We change all call sites to use this new interface. This still doesn't
give us the missing level IRQ handling, but at least prepares the callers
to do the right thing later automatically.

Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
---
Changelog:
- keep function as returning void

 xen/arch/arm/domain.c      |  4 ++--
 xen/arch/arm/gic-v3-lpi.c  |  2 +-
 xen/arch/arm/irq.c         |  2 +-
 xen/arch/arm/time.c        |  2 +-
 xen/arch/arm/vgic.c        | 39 +++++++++++++++++++++++----------------
 xen/arch/arm/vpl011.c      |  2 +-
 xen/arch/arm/vtimer.c      |  4 ++--
 xen/include/asm-arm/vgic.h |  4 ++--
 8 files changed, 33 insertions(+), 26 deletions(-)

Comments

Julien Grall March 12, 2018, 11:29 a.m. | #1
Hi,

On 09/03/18 15:11, Andre Przywara wrote:
> At the moment vgic_vcpu_inject_irq() is the interface for Xen internal
> code and virtual devices to inject IRQs into a guest. This interface has
> two shortcomings:
> 1) It requires a VCPU pointer, which we may not know (and don't need!)
> for shared interrupts. A second function (vgic_vcpu_inject_spi()), was
> there to work around this issue.
> 2) This interface only really supports edge triggered IRQs, which is
> what the Xen VGIC emulates only anyway. However this needs to and will
> change, so we need to add the desired level (high or low) to the
> interface.
> This replaces the existing injection call (taking a VCPU and an IRQ
> parameter) with a new one, taking domain, VCPU, IRQ and level parameters.
> The VCPU can be NULL in case we don't know and don't care.
> We change all call sites to use this new interface. This still doesn't
> give us the missing level IRQ handling, but at least prepares the callers
> to do the right thing later automatically.
> 
> Signed-off-by: Andre Przywara <andre.przywara@linaro.org>

Reviewed-by: Julien Grall <julien.grall@arm.com>

Cheers,

> ---
> Changelog:
> - keep function as returning void
> 
>   xen/arch/arm/domain.c      |  4 ++--
>   xen/arch/arm/gic-v3-lpi.c  |  2 +-
>   xen/arch/arm/irq.c         |  2 +-
>   xen/arch/arm/time.c        |  2 +-
>   xen/arch/arm/vgic.c        | 39 +++++++++++++++++++++++----------------
>   xen/arch/arm/vpl011.c      |  2 +-
>   xen/arch/arm/vtimer.c      |  4 ++--
>   xen/include/asm-arm/vgic.h |  4 ++--
>   8 files changed, 33 insertions(+), 26 deletions(-)
> 
> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> index 6b902fa30f..bc10f412ba 100644
> --- a/xen/arch/arm/domain.c
> +++ b/xen/arch/arm/domain.c
> @@ -951,14 +951,14 @@ void vcpu_mark_events_pending(struct vcpu *v)
>       if ( already_pending )
>           return;
>   
> -    vgic_vcpu_inject_irq(v, v->domain->arch.evtchn_irq);
> +    vgic_inject_irq(v->domain, v, v->domain->arch.evtchn_irq, true);
>   }
>   
>   /* The ARM spec declares that even if local irqs are masked in
>    * the CPSR register, an irq should wake up a cpu from WFI anyway.
>    * For this reason we need to check for irqs that need delivery,
>    * ignoring the CPSR register, *after* calling SCHEDOP_block to
> - * avoid races with vgic_vcpu_inject_irq.
> + * avoid races with vgic_inject_irq.
>    */
>   void vcpu_block_unless_event_pending(struct vcpu *v)
>   {
> diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
> index 84582157b8..efd5cd62fb 100644
> --- a/xen/arch/arm/gic-v3-lpi.c
> +++ b/xen/arch/arm/gic-v3-lpi.c
> @@ -153,7 +153,7 @@ void vgic_vcpu_inject_lpi(struct domain *d, unsigned int virq)
>       if ( vcpu_id >= d->max_vcpus )
>             return;
>   
> -    vgic_vcpu_inject_irq(d->vcpu[vcpu_id], virq);
> +    vgic_inject_irq(d, d->vcpu[vcpu_id], virq, true);
>   }
>   
>   /*
> diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
> index 29af10e82c..aa4e832cae 100644
> --- a/xen/arch/arm/irq.c
> +++ b/xen/arch/arm/irq.c
> @@ -225,7 +225,7 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq)
>            * The irq cannot be a PPI, we only support delivery of SPIs to
>            * guests.
>   	 */
> -        vgic_vcpu_inject_spi(info->d, info->virq);
> +        vgic_inject_irq(info->d, NULL, info->virq, true);
>           goto out_no_end;
>       }
>   
> diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
> index 36f640f0c1..c11fcfeadd 100644
> --- a/xen/arch/arm/time.c
> +++ b/xen/arch/arm/time.c
> @@ -260,7 +260,7 @@ static void vtimer_interrupt(int irq, void *dev_id, struct cpu_user_regs *regs)
>   
>       current->arch.virt_timer.ctl = READ_SYSREG32(CNTV_CTL_EL0);
>       WRITE_SYSREG32(current->arch.virt_timer.ctl | CNTx_CTL_MASK, CNTV_CTL_EL0);
> -    vgic_vcpu_inject_irq(current, current->arch.virt_timer.irq);
> +    vgic_inject_irq(current->domain, current, current->arch.virt_timer.irq, true);
>   }
>   
>   /*
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index fa00c21a69..eb09d9ca54 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -291,7 +291,7 @@ bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq)
>           vgic_remove_irq_from_queues(old, p);
>           irq_set_affinity(p->desc, cpumask_of(new->processor));
>           spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
> -        vgic_vcpu_inject_irq(new, irq);
> +        vgic_inject_irq(new->domain, new, irq, true);
>           return true;
>       }
>       /* if the IRQ is in a GICH_LR register, set GIC_IRQ_GUEST_MIGRATING
> @@ -450,7 +450,7 @@ bool vgic_to_sgi(struct vcpu *v, register_t sgir, enum gic_sgi_mode irqmode,
>                           sgir, target->list);
>                   continue;
>               }
> -            vgic_vcpu_inject_irq(d->vcpu[vcpuid], virq);
> +            vgic_inject_irq(d, d->vcpu[vcpuid], virq, true);
>           }
>           break;
>       case SGI_TARGET_OTHERS:
> @@ -459,12 +459,12 @@ bool vgic_to_sgi(struct vcpu *v, register_t sgir, enum gic_sgi_mode irqmode,
>           {
>               if ( i != current->vcpu_id && d->vcpu[i] != NULL &&
>                    is_vcpu_online(d->vcpu[i]) )
> -                vgic_vcpu_inject_irq(d->vcpu[i], virq);
> +                vgic_inject_irq(d, d->vcpu[i], virq, true);
>           }
>           break;
>       case SGI_TARGET_SELF:
>           perfc_incr(vgic_sgi_self);
> -        vgic_vcpu_inject_irq(d->vcpu[current->vcpu_id], virq);
> +        vgic_inject_irq(d, current, virq, true);
>           break;
>       default:
>           gprintk(XENLOG_WARNING,
> @@ -524,13 +524,29 @@ void vgic_remove_irq_from_queues(struct vcpu *v, struct pending_irq *p)
>       gic_remove_from_lr_pending(v, p);
>   }
>   
> -void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int virq)
> +void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq,
> +                     bool level)
>   {
>       uint8_t priority;
>       struct pending_irq *iter, *n;
>       unsigned long flags;
>       bool running;
>   
> +    /*
> +     * For edge triggered interrupts we always ignore a "falling edge".
> +     * For level triggered interrupts we shouldn't, but do anyways.
> +     */
> +    if ( !level )
> +        return;
> +
> +    if ( !v )
> +    {
> +        /* The IRQ needs to be an SPI if no vCPU is specified. */
> +        ASSERT(virq >= 32 && virq <= vgic_num_irqs(d));
> +
> +        v = vgic_get_target_vcpu(d->vcpu[0], virq);
> +    };
> +
>       spin_lock_irqsave(&v->arch.vgic.lock, flags);
>   
>       n = irq_to_pending(v, virq);
> @@ -582,22 +598,13 @@ out:
>           perfc_incr(vgic_cross_cpu_intr_inject);
>           smp_send_event_check_mask(cpumask_of(v->processor));
>       }
> -}
> -
> -void vgic_vcpu_inject_spi(struct domain *d, unsigned int virq)
> -{
> -    struct vcpu *v;
> -
> -    /* the IRQ needs to be an SPI */
> -    ASSERT(virq >= 32 && virq <= vgic_num_irqs(d));
>   
> -    v = vgic_get_target_vcpu(d->vcpu[0], virq);
> -    vgic_vcpu_inject_irq(v, virq);
> +    return;
>   }
>   
>   void arch_evtchn_inject(struct vcpu *v)
>   {
> -    vgic_vcpu_inject_irq(v, v->domain->arch.evtchn_irq);
> +    vgic_inject_irq(v->domain, v, v->domain->arch.evtchn_irq, true);
>   }
>   
>   bool vgic_evtchn_irq_pending(struct vcpu *v)
> diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
> index 7788c2fc32..5dcf4bec18 100644
> --- a/xen/arch/arm/vpl011.c
> +++ b/xen/arch/arm/vpl011.c
> @@ -68,7 +68,7 @@ static void vpl011_update_interrupt_status(struct domain *d)
>        * status bit has been set since the last time.
>        */
>       if ( uartmis & ~vpl011->shadow_uartmis )
> -        vgic_vcpu_inject_spi(d, GUEST_VPL011_SPI);
> +        vgic_inject_irq(d, NULL, GUEST_VPL011_SPI, true);
>   
>       vpl011->shadow_uartmis = uartmis;
>   }
> diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
> index f52a723a5f..8164f6c7f1 100644
> --- a/xen/arch/arm/vtimer.c
> +++ b/xen/arch/arm/vtimer.c
> @@ -46,7 +46,7 @@ static void phys_timer_expired(void *data)
>       if ( !(t->ctl & CNTx_CTL_MASK) )
>       {
>           perfc_incr(vtimer_phys_inject);
> -        vgic_vcpu_inject_irq(t->v, t->irq);
> +        vgic_inject_irq(t->v->domain, t->v, t->irq, true);
>       }
>       else
>           perfc_incr(vtimer_phys_masked);
> @@ -56,7 +56,7 @@ static void virt_timer_expired(void *data)
>   {
>       struct vtimer *t = data;
>       t->ctl |= CNTx_CTL_MASK;
> -    vgic_vcpu_inject_irq(t->v, t->irq);
> +    vgic_inject_irq(t->v->domain, t->v, t->irq, true);
>       perfc_incr(vtimer_virt_inject);
>   }
>   
> diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
> index afb4776ad4..8af6d816c9 100644
> --- a/xen/include/asm-arm/vgic.h
> +++ b/xen/include/asm-arm/vgic.h
> @@ -202,8 +202,8 @@ extern int domain_vgic_init(struct domain *d, unsigned int nr_spis);
>   extern void domain_vgic_free(struct domain *d);
>   extern int vcpu_vgic_init(struct vcpu *v);
>   extern struct vcpu *vgic_get_target_vcpu(struct vcpu *v, unsigned int virq);
> -extern void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int virq);
> -extern void vgic_vcpu_inject_spi(struct domain *d, unsigned int virq);
> +extern void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq,
> +                            bool level);
>   extern void vgic_remove_irq_from_queues(struct vcpu *v, struct pending_irq *p);
>   extern void gic_remove_from_lr_pending(struct vcpu *v, struct pending_irq *p);
>   extern void vgic_clear_pending_irqs(struct vcpu *v);
>

Patch

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 6b902fa30f..bc10f412ba 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -951,14 +951,14 @@  void vcpu_mark_events_pending(struct vcpu *v)
     if ( already_pending )
         return;
 
-    vgic_vcpu_inject_irq(v, v->domain->arch.evtchn_irq);
+    vgic_inject_irq(v->domain, v, v->domain->arch.evtchn_irq, true);
 }
 
 /* The ARM spec declares that even if local irqs are masked in
  * the CPSR register, an irq should wake up a cpu from WFI anyway.
  * For this reason we need to check for irqs that need delivery,
  * ignoring the CPSR register, *after* calling SCHEDOP_block to
- * avoid races with vgic_vcpu_inject_irq.
+ * avoid races with vgic_inject_irq.
  */
 void vcpu_block_unless_event_pending(struct vcpu *v)
 {
diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
index 84582157b8..efd5cd62fb 100644
--- a/xen/arch/arm/gic-v3-lpi.c
+++ b/xen/arch/arm/gic-v3-lpi.c
@@ -153,7 +153,7 @@  void vgic_vcpu_inject_lpi(struct domain *d, unsigned int virq)
     if ( vcpu_id >= d->max_vcpus )
           return;
 
-    vgic_vcpu_inject_irq(d->vcpu[vcpu_id], virq);
+    vgic_inject_irq(d, d->vcpu[vcpu_id], virq, true);
 }
 
 /*
diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index 29af10e82c..aa4e832cae 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -225,7 +225,7 @@  void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq)
          * The irq cannot be a PPI, we only support delivery of SPIs to
          * guests.
 	 */
-        vgic_vcpu_inject_spi(info->d, info->virq);
+        vgic_inject_irq(info->d, NULL, info->virq, true);
         goto out_no_end;
     }
 
diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
index 36f640f0c1..c11fcfeadd 100644
--- a/xen/arch/arm/time.c
+++ b/xen/arch/arm/time.c
@@ -260,7 +260,7 @@  static void vtimer_interrupt(int irq, void *dev_id, struct cpu_user_regs *regs)
 
     current->arch.virt_timer.ctl = READ_SYSREG32(CNTV_CTL_EL0);
     WRITE_SYSREG32(current->arch.virt_timer.ctl | CNTx_CTL_MASK, CNTV_CTL_EL0);
-    vgic_vcpu_inject_irq(current, current->arch.virt_timer.irq);
+    vgic_inject_irq(current->domain, current, current->arch.virt_timer.irq, true);
 }
 
 /*
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index fa00c21a69..eb09d9ca54 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -291,7 +291,7 @@  bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq)
         vgic_remove_irq_from_queues(old, p);
         irq_set_affinity(p->desc, cpumask_of(new->processor));
         spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
-        vgic_vcpu_inject_irq(new, irq);
+        vgic_inject_irq(new->domain, new, irq, true);
         return true;
     }
     /* if the IRQ is in a GICH_LR register, set GIC_IRQ_GUEST_MIGRATING
@@ -450,7 +450,7 @@  bool vgic_to_sgi(struct vcpu *v, register_t sgir, enum gic_sgi_mode irqmode,
                         sgir, target->list);
                 continue;
             }
-            vgic_vcpu_inject_irq(d->vcpu[vcpuid], virq);
+            vgic_inject_irq(d, d->vcpu[vcpuid], virq, true);
         }
         break;
     case SGI_TARGET_OTHERS:
@@ -459,12 +459,12 @@  bool vgic_to_sgi(struct vcpu *v, register_t sgir, enum gic_sgi_mode irqmode,
         {
             if ( i != current->vcpu_id && d->vcpu[i] != NULL &&
                  is_vcpu_online(d->vcpu[i]) )
-                vgic_vcpu_inject_irq(d->vcpu[i], virq);
+                vgic_inject_irq(d, d->vcpu[i], virq, true);
         }
         break;
     case SGI_TARGET_SELF:
         perfc_incr(vgic_sgi_self);
-        vgic_vcpu_inject_irq(d->vcpu[current->vcpu_id], virq);
+        vgic_inject_irq(d, current, virq, true);
         break;
     default:
         gprintk(XENLOG_WARNING,
@@ -524,13 +524,29 @@  void vgic_remove_irq_from_queues(struct vcpu *v, struct pending_irq *p)
     gic_remove_from_lr_pending(v, p);
 }
 
-void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int virq)
+void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq,
+                     bool level)
 {
     uint8_t priority;
     struct pending_irq *iter, *n;
     unsigned long flags;
     bool running;
 
+    /*
+     * For edge triggered interrupts we always ignore a "falling edge".
+     * For level triggered interrupts we shouldn't, but do anyways.
+     */
+    if ( !level )
+        return;
+
+    if ( !v )
+    {
+        /* The IRQ needs to be an SPI if no vCPU is specified. */
+        ASSERT(virq >= 32 && virq <= vgic_num_irqs(d));
+
+        v = vgic_get_target_vcpu(d->vcpu[0], virq);
+    };
+
     spin_lock_irqsave(&v->arch.vgic.lock, flags);
 
     n = irq_to_pending(v, virq);
@@ -582,22 +598,13 @@  out:
         perfc_incr(vgic_cross_cpu_intr_inject);
         smp_send_event_check_mask(cpumask_of(v->processor));
     }
-}
-
-void vgic_vcpu_inject_spi(struct domain *d, unsigned int virq)
-{
-    struct vcpu *v;
-
-    /* the IRQ needs to be an SPI */
-    ASSERT(virq >= 32 && virq <= vgic_num_irqs(d));
 
-    v = vgic_get_target_vcpu(d->vcpu[0], virq);
-    vgic_vcpu_inject_irq(v, virq);
+    return;
 }
 
 void arch_evtchn_inject(struct vcpu *v)
 {
-    vgic_vcpu_inject_irq(v, v->domain->arch.evtchn_irq);
+    vgic_inject_irq(v->domain, v, v->domain->arch.evtchn_irq, true);
 }
 
 bool vgic_evtchn_irq_pending(struct vcpu *v)
diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
index 7788c2fc32..5dcf4bec18 100644
--- a/xen/arch/arm/vpl011.c
+++ b/xen/arch/arm/vpl011.c
@@ -68,7 +68,7 @@  static void vpl011_update_interrupt_status(struct domain *d)
      * status bit has been set since the last time.
      */
     if ( uartmis & ~vpl011->shadow_uartmis )
-        vgic_vcpu_inject_spi(d, GUEST_VPL011_SPI);
+        vgic_inject_irq(d, NULL, GUEST_VPL011_SPI, true);
 
     vpl011->shadow_uartmis = uartmis;
 }
diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
index f52a723a5f..8164f6c7f1 100644
--- a/xen/arch/arm/vtimer.c
+++ b/xen/arch/arm/vtimer.c
@@ -46,7 +46,7 @@  static void phys_timer_expired(void *data)
     if ( !(t->ctl & CNTx_CTL_MASK) )
     {
         perfc_incr(vtimer_phys_inject);
-        vgic_vcpu_inject_irq(t->v, t->irq);
+        vgic_inject_irq(t->v->domain, t->v, t->irq, true);
     }
     else
         perfc_incr(vtimer_phys_masked);
@@ -56,7 +56,7 @@  static void virt_timer_expired(void *data)
 {
     struct vtimer *t = data;
     t->ctl |= CNTx_CTL_MASK;
-    vgic_vcpu_inject_irq(t->v, t->irq);
+    vgic_inject_irq(t->v->domain, t->v, t->irq, true);
     perfc_incr(vtimer_virt_inject);
 }
 
diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
index afb4776ad4..8af6d816c9 100644
--- a/xen/include/asm-arm/vgic.h
+++ b/xen/include/asm-arm/vgic.h
@@ -202,8 +202,8 @@  extern int domain_vgic_init(struct domain *d, unsigned int nr_spis);
 extern void domain_vgic_free(struct domain *d);
 extern int vcpu_vgic_init(struct vcpu *v);
 extern struct vcpu *vgic_get_target_vcpu(struct vcpu *v, unsigned int virq);
-extern void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int virq);
-extern void vgic_vcpu_inject_spi(struct domain *d, unsigned int virq);
+extern void vgic_inject_irq(struct domain *d, struct vcpu *v, unsigned int virq,
+                            bool level);
 extern void vgic_remove_irq_from_queues(struct vcpu *v, struct pending_irq *p);
 extern void gic_remove_from_lr_pending(struct vcpu *v, struct pending_irq *p);
 extern void vgic_clear_pending_irqs(struct vcpu *v);