arm/acpi: Configure SPI interrupt type and route to Dom0 dynamically

Interrupt information is described in DSDT and is not available at the
time of booting. Check if the interrupt is permitted to access and set
the interrupt type, route it to guest dynamically only for SPI
and Dom0.

Signed-off-by: Parth Dixit <parth.dixit@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Julien Grall <julien.grall@arm.com>

xen/arch/arm/vgic.c

@@ -25,6 +25,8 @@
 #include <xen/irq.h>
 #include <xen/sched.h>
 #include <xen/perfc.h>
+#include <xen/iocap.h>
+#include <xen/acpi.h>
 
 #include <asm/current.h>
 
@@ -334,6 +336,19 @@ void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
     }
 }
 
+#define VGIC_ICFG_MASK(intr) (1 << ((2 * ((intr) % 16)) + 1))
+
+static inline unsigned int get_the_irq_type(struct vcpu *v, int n, int index)
+{
+    struct vgic_irq_rank *vr = vgic_get_rank(v, n);
+    uint32_t tr = vr->icfg[index >> 4];
+
+    if ( tr & VGIC_ICFG_MASK(index) )
+        return IRQ_TYPE_EDGE_BOTH;
+    else
+        return IRQ_TYPE_LEVEL_MASK;
+}
+
 void vgic_enable_irqs(struct vcpu *v, uint32_t r, int n)
 {
     const unsigned long mask = r;
@@ -342,9 +357,26 @@ void vgic_enable_irqs(struct vcpu *v, uint32_t r, int n)
     unsigned long flags;
     int i = 0;
     struct vcpu *v_target;
+    struct domain *d = v->domain;
+    int ret;
 
     while ( (i = find_next_bit(&mask, 32, i)) < 32 ) {
         irq = i + (32 * n);
+        /* Set the irq type and route it to guest only for SPI and Dom0 */
+        if( irq_access_permitted(d, irq) && is_hardware_domain(d) &&
+            ( irq >= 32 ) && ( !acpi_disabled ) )
+        {
+            ret = irq_set_spi_type(irq, get_the_irq_type(v, n, i));
+            if ( ret )
+                gprintk(XENLOG_WARNING, "The irq type is not correct\n");
+
+            vgic_reserve_virq(d, irq);
+
+            ret = route_irq_to_guest(d, irq, irq, NULL);
+            if ( ret )
+                gprintk(XENLOG_ERR, "Unable to route IRQ %u to domain %u\n",
+                        irq, d->domain_id);
+        }
         v_target = __vgic_get_target_vcpu(v, irq);
         p = irq_to_pending(v_target, irq);
         set_bit(GIC_IRQ_GUEST_ENABLED, &p->status);