This patch allocates Virtio MMIO params (IRQ and memory region) and pass
them to the backend, also update Guest device-tree based on Virtio GPIO
DT bindings [1].

[1] https://www.kernel.org/doc/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 tools/libs/light/libxl_arm.c | 46 ++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
index d085c7cf4dbd..2f23430a3ea3 100644
--- a/tools/libs/light/libxl_arm.c
+++ b/tools/libs/light/libxl_arm.c
@@ -119,6 +119,15 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
             return rc;
     }
 
+    for (i = 0; i < d_config->num_gpios; i++) {
+        libxl_device_gpio *gpio = &d_config->gpios[i];
+
+    int rc = alloc_virtio_mmio_params(gc, &gpio->base, &gpio->irq,
+            &virtio_mmio_base, &virtio_mmio_irq);
+    if (rc)
+        return rc;
+    }
+
     if (virtio_mmio_irq != GUEST_VIRTIO_MMIO_SPI_FIRST) {
         virtio_irq = virtio_mmio_irq - 1;
         nr_spis += (virtio_irq - 32) + 1;
@@ -938,6 +947,38 @@ static int make_virtio_mmio_node_i2c(libxl__gc *gc, void *fdt,
     return fdt_end_node(fdt);
 }
 
+static int make_virtio_mmio_node_gpio(libxl__gc *gc, void *fdt,
+                                 uint64_t base, uint32_t irq)
+{
+    int res;
+
+    res = make_virtio_mmio_node_common(gc, fdt, base, irq);
+    if (res) return res;
+
+    res = fdt_begin_node(fdt, "gpio");
+    if (res) return res;
+
+    res = fdt_property_compat(gc, fdt, 1, "virtio,device29");
+    if (res) return res;
+
+    res = fdt_property(fdt, "gpio-controller", NULL, 0);
+    if (res) return res;
+
+    res = fdt_property_cell(fdt, "#gpio-cells", 2);
+    if (res) return res;
+
+    res = fdt_property(fdt, "interrupt-controller", NULL, 0);
+    if (res) return res;
+
+    res = fdt_property_cell(fdt, "#interrupt-cells", 2);
+    if (res) return res;
+
+    res = fdt_end_node(fdt);
+    if (res) return res;
+
+    return fdt_end_node(fdt);
+}
+
 static const struct arch_info *get_arch_info(libxl__gc *gc,
                                              const struct xc_dom_image *dom)
 {
@@ -1253,6 +1294,11 @@ static int libxl__prepare_dtb(libxl__gc *gc, libxl_domain_config *d_config,
                 FDT( make_virtio_mmio_node_simple(gc, fdt, disk->base, disk->irq) );
         }
 
+        for (i = 0; i < d_config->num_gpios; i++) {
+            libxl_device_gpio *gpio = &d_config->gpios[i];
+            FDT( make_virtio_mmio_node_gpio(gc, fdt, gpio->base, gpio->irq) );
+        }
+
         for (i = 0; i < d_config->num_i2cs; i++) {
             libxl_device_i2c *i2c = &d_config->i2cs[i];
             FDT( make_virtio_mmio_node_i2c(gc, fdt, i2c->base, i2c->irq) );
-- 
2.31.1.272.g89b43f80a514