Advertise the GICv5 in the DTB. This binding is final as it is in
the upstream Linux kernel as:
Documentation/devicetree/bindings/interrupt-controller/arm,gic-v5.yaml

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 hw/arm/virt.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index b6a04f868b..7a34af766a 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -794,6 +794,72 @@ static void create_v2m(VirtMachineState *vms)
     vms->msi_controller = VIRT_MSI_CTRL_GICV2M;
 }
 
+static void fdt_add_gicv5_node(VirtMachineState *vms)
+{
+    MachineState *ms = MACHINE(vms);
+    const char *nodename = "/intc";
+    g_autofree char *irsnodename = NULL;
+    g_autofree uint32_t *cpu_phandles = g_new(uint32_t, ms->smp.cpus);
+    g_autofree uint16_t *iaffids = g_new(uint16_t, ms->smp.cpus);
+
+    vms->gic_phandle = qemu_fdt_alloc_phandle(ms->fdt);
+    qemu_fdt_setprop_cell(ms->fdt, "/", "interrupt-parent", vms->gic_phandle);
+
+    qemu_fdt_add_subnode(ms->fdt, nodename);
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "phandle", vms->gic_phandle);
+    qemu_fdt_setprop_string(ms->fdt, nodename, "compatible", "arm,gic-v5");
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "#interrupt-cells", 3);
+    qemu_fdt_setprop(ms->fdt, nodename, "interrupt-controller", NULL, 0);
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "#address-cells", 0x2);
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "#size-cells", 0x2);
+    qemu_fdt_setprop(ms->fdt, nodename, "ranges", NULL, 0);
+
+    /* The IRS node is a child of the top level /intc node */
+    irsnodename = g_strdup_printf("%s/irs@%" PRIx64,
+                                  nodename,
+                                  vms->memmap[VIRT_GICV5_IRS_NS].base);
+    qemu_fdt_add_subnode(ms->fdt, irsnodename);
+    qemu_fdt_setprop_string(ms->fdt, irsnodename, "compatible",
+                            "arm,gic-v5-irs");
+    /*
+     * "reg-names" describes the frames whose address/size is in "reg";
+     * at the moment we have only the NS config register frame.
+     */
+    qemu_fdt_setprop_string(ms->fdt, irsnodename, "reg-names", "ns-config");
+    qemu_fdt_setprop_sized_cells(ms->fdt, irsnodename, "reg",
+                                 2, vms->memmap[VIRT_GICV5_IRS_NS].base,
+                                 2, vms->memmap[VIRT_GICV5_IRS_NS].size);
+    qemu_fdt_setprop_cell(ms->fdt, irsnodename, "#address-cells", 0x2);
+    qemu_fdt_setprop_cell(ms->fdt, irsnodename, "#size-cells", 0x2);
+    qemu_fdt_setprop(ms->fdt, irsnodename, "ranges", NULL, 0);
+
+    /*
+     * The "cpus" property is an array of phandles to the CPUs, and
+     * "iaffids" is an array of uint16 IAFFIDs. For virt, our IAFFIDs
+     * are the CPU indexes.  This function is called after
+     * fdt_add_cpu_nodes(), which allocates the cpu_phandles array.
+     */
+    assert(vms->cpu_phandles);
+    for (int i = 0; i < ms->smp.cpus; i++) {
+        /*
+         * We have to byteswap each element here because we're setting the
+         * whole property value at once as a lump of raw data, not via a
+         * helper like qemu_fdt_setprop_cell() that does the swapping for us.
+         */
+        cpu_phandles[i] = cpu_to_be32(vms->cpu_phandles[i]);
+        iaffids[i] = cpu_to_be16(i);
+    }
+    qemu_fdt_setprop(ms->fdt, irsnodename, "cpus", cpu_phandles,
+                     ms->smp.cpus * sizeof(*cpu_phandles));
+    qemu_fdt_setprop(ms->fdt, irsnodename, "arm,iaffids", iaffids,
+                     ms->smp.cpus * sizeof(*iaffids));
+
+    /*
+     * When we implement the GICv5 IRS, it gets a DTB node which is a
+     * child of the IRS node.
+     */
+}
+
 static void create_gicv5(VirtMachineState *vms, MemoryRegion *mem)
 {
     MachineState *ms = MACHINE(vms);
@@ -835,6 +901,8 @@ static void create_gicv5(VirtMachineState *vms, MemoryRegion *mem)
      * that information is communicated directly between a GICv5 IRS and
      * the GICv5 CPU interface via our equivalent of the stream protocol.
      */
+
+    fdt_add_gicv5_node(vms);
 }
 
 /*
-- 
2.43.0