xen: Introduce Xen Interrupt Controller

Every set_irq call makes a Xen hypercall.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

hw/pc_piix.c

@@ -110,8 +110,12 @@ static void pc_init1(ram_addr_t ram_size,
                        below_4g_mem_size, above_4g_mem_size);
     }
 
-    cpu_irq = pc_allocate_cpu_irq();
-    i8259 = i8259_init(cpu_irq[0]);
+    if (!xen_enabled()) {
+        cpu_irq = pc_allocate_cpu_irq();
+        i8259 = i8259_init(cpu_irq[0]);
+    } else {
+        i8259 = xen_interrupt_controller_init();
+    }
     isa_irq_state = qemu_mallocz(sizeof(*isa_irq_state));
     isa_irq_state->i8259 = i8259;
     if (pci_enabled) {

hw/xen.h

@@ -35,6 +35,8 @@ int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num);
 void xen_piix3_set_irq(void *opaque, int irq_num, int level);
 void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len);
 
+qemu_irq *xen_interrupt_controller_init(void);
+
 int xen_init(void);
 int xen_hvm_init(void);
 void xen_vcpu_init(void);

xen-all.c

@@ -40,6 +40,18 @@ void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len)
     }
 }
 
+/* Xen Interrupt Controller */
+
+static void xen_set_irq(void *opaque, int irq, int level)
+{
+    xc_hvm_set_isa_irq_level(xen_xc, xen_domid, irq, level);
+}
+
+qemu_irq *xen_interrupt_controller_init(void)
+{
+    return qemu_allocate_irqs(xen_set_irq, NULL, 16);
+}
+
 /* VCPU Operations, MMIO, IO ring ... */
 
 static void xen_reset_vcpu(void *opaque)

xen-stub.c

@@ -22,6 +22,11 @@ void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len)
 {
 }
 
+qemu_irq *xen_interrupt_controller_init(void)
+{
+    return NULL;
+}
+
 int xen_init(void)
 {
     return -ENOSYS;