xen/arm: physical irq follow virtual irq

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.

In case of virq migration, if the virq is inflight and in a GICH_LR
register already, delay migrating the corresponding physical irq until
the virq is EOIed by the guest and the MIGRATING flag has been cleared.
This way we make sure that the pcpu running the old vcpu gets
interrupted with a new irq of the same kind, clearing the GICH_LR sooner.

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>
Acked-by: Julien Grall <julien.grall@linaro.org>

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 130554206e9d54529f6f89f6182363c85a7180f1..da60a41aef7dc2e480f20c894514df2886d3b322 100644 (file)
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -569,9 +569,20 @@ static void gicv2_guest_irq_end(struct irq_desc *desc)
     /* Deactivation happens in maintenance interrupt / via GICV */
 }
 
-static void gicv2_irq_set_affinity(struct irq_desc *desc, const cpumask_t *mask)
+static void gicv2_irq_set_affinity(struct irq_desc *desc, const cpumask_t *cpu_mask)
 {
-    BUG();
+    unsigned int mask;
+
+    ASSERT(!cpumask_empty(cpu_mask));
+
+    spin_lock(&gicv2.lock);
+
+    mask = gicv2_cpu_mask(cpu_mask);
+
+    /* Set target CPU mask (RAZ/WI on uniprocessor) */
+    writeb_gicd(mask, GICD_ITARGETSR + desc->irq);
+
+    spin_unlock(&gicv2.lock);
 }
 
 /* XXX different for level vs edge */

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index f5c7c9145e4dc97a06ebce13e36ec9f089b54c12..2aa95005e3d092a0528962c068ba9c74ad18b95e 100644 (file)
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -382,7 +382,11 @@ static void gic_update_one_lr(struct vcpu *v, int i)
             gic_raise_guest_irq(v, irq, p->priority);
         else {
             list_del_init(&p->inflight);
-            clear_bit(GIC_IRQ_GUEST_MIGRATING, &p->status);
+            if ( test_and_clear_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) )
+            {
+                struct vcpu *v_target = vgic_get_target_vcpu(v, irq);
+                irq_set_affinity(p->desc, cpumask_of(v_target->processor));
+            }
         }
     }
 }

diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index 49ca467841d8abd03ca46ab7223193d7ff0b35b2..7150c7ace26c970c47658d7fffa176b5a0c60e89 100644 (file)
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -134,6 +134,12 @@ static inline struct domain *irq_get_domain(struct irq_desc *desc)
     return desc->action->dev_id;
 }
 
+void irq_set_affinity(struct irq_desc *desc, const cpumask_t *cpu_mask)
+{
+    if ( desc != NULL )
+        desc->handler->set_affinity(desc, cpu_mask);
+}
+
 int request_irq(unsigned int irq, unsigned int irqflags,
                 void (*handler)(int, void *, struct cpu_user_regs *),
                 const char *devname, void *dev_id)

diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index ed7108eab24ecee7c30dfbf9e2a7d05309c5fcb6..2319d714a253f225d2a2efd9ee46f20286ad62d9 100644 (file)
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -182,6 +182,7 @@ void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq)
 
     if ( list_empty(&p->inflight) )
     {
+        irq_set_affinity(p->desc, cpumask_of(new->processor));
         spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
         return;
     }
@@ -191,6 +192,7 @@ void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq)
         clear_bit(GIC_IRQ_GUEST_QUEUED, &p->status);
         list_del_init(&p->lr_queue);
         list_del_init(&p->inflight);
+        irq_set_affinity(p->desc, cpumask_of(new->processor));
         spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
         vgic_vcpu_inject_irq(new, irq);
         return;
@@ -203,6 +205,24 @@ void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq)
     spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
 }
 
+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 + 32); i++ )
+    {
+        v_target = vgic_get_target_vcpu(v, i);
+        p = irq_to_pending(v_target, i);
+
+        if ( v_target == v && !test_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) )
+            irq_set_affinity(p->desc, cpu_mask);
+    }
+}
+
 void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
 {
     struct domain *d = v->domain;
@@ -260,6 +280,7 @@ 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);

diff --git a/xen/include/asm-arm/irq.h b/xen/include/asm-arm/irq.h
index e567f712ec159d9e8b26ac83eb8fc1f649b0dfec..e877334c0865a8476ada42bb5a79525c286b4108 100644 (file)
--- a/xen/include/asm-arm/irq.h
+++ b/xen/include/asm-arm/irq.h
@@ -42,12 +42,15 @@ void init_secondary_IRQ(void);
 
 int route_irq_to_guest(struct domain *d, unsigned int irq,
                        const char *devname);
+void arch_move_irqs(struct vcpu *v);
 
 /* Set IRQ type for an SPI */
 int irq_set_spi_type(unsigned int spi, unsigned int type);
 
 int platform_get_irq(const struct dt_device_node *device, int index);
 
+void irq_set_affinity(struct irq_desc *desc, const cpumask_t *cpu_mask);
+
 #endif /* _ASM_HW_IRQ_H */
 /*
  * Local variables:

diff --git a/xen/include/asm-x86/irq.h b/xen/include/asm-x86/irq.h
index 9066d3892cc7ac6940f361c6a2c46b83520476fd..d3c55f362fe96e4caa61429d53766b9f88685c10 100644 (file)
--- 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 */