(+ Bertrand)
Hi Viresh,
On 22/08/2022 10:15, Viresh Kumar wrote:
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
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshche...@epam.com>
Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
tools/libs/light/libxl_arm.c | 51 ++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
index 4c1012e56893..86c1e560900f 100644
--- a/tools/libs/light/libxl_arm.c
+++ b/tools/libs/light/libxl_arm.c
@@ -121,6 +121,15 @@ 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;
+ }
+
/*
* Every virtio-mmio device uses one emulated SPI. If Virtio devices are
* present, make sure that we allocate enough SPIs for them.
@@ -984,6 +993,38 @@ static int make_virtio_mmio_node_i2c(libxl__gc *gc, void
*fdt, uint64_t base,
return fdt_end_node(fdt);
}
+static int make_virtio_mmio_node_gpio(libxl__gc *gc, void *fdt, uint64_t base,
+ uint32_t irq, uint32_t backend_domid)
+{
+ int res;
+
+ res = make_virtio_mmio_node_common(gc, fdt, base, irq, backend_domid);
+ if (res) return res;
+
+ res = fdt_begin_node(fdt, "gpio");
+ if (res) return res;
+
+ res = fdt_property_compat(gc, fdt, 1, "virtio,device29");
It is a very descriptive compatible :). And yes I realize this is the
compatible chosen by upstream.
+ 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)
{
@@ -1317,6 +1358,16 @@ static int libxl__prepare_dtb(libxl__gc *gc,
libxl_domain_config *d_config,
i2c->backend_domid) );
}
+ for (i = 0; i < d_config->num_gpios; i++) {
+ libxl_device_gpio *gpio = &d_config->gpios[i];
+
+ if (gpio->backend_domid != LIBXL_TOOLSTACK_DOMID)
+ iommu_needed = true;
+
+ FDT( make_virtio_mmio_node_gpio(gc, fdt, gpio->base, gpio->irq,
+ gpio->backend_domid) );
So this is exposing a GPIO interrupt controller but IIUC we will also
need to describe the devices in the device-tree. Can you outline how you
would expect it to work?
To put some context, this is related to what I wrote in patch #1. How
much code will be necessary in libxl to add new device?
I am not the maintainer of this code, but I would expect some example
how this can be used once this merged. This would help us to understand
whether the interface is correct.
Cheers,
--
Julien Grall
