Re: [Qemu-devel] [PATCH v5 10/10] hw/arm/dyn_sysbus_devtree: enable simple VFIO dynamic instantiation

[Alexander Graf <agraf@suse.de>]

On 09.08.14 16:25, Eric Auger wrote:
> Generates the device node of VFIO devices, if any are invoked in
> -device option. In case VFIO devices require more complex node
> generation, they can be handled before.
>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> ---
>   hw/arm/dyn_sysbus_devtree.c | 138 ++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 138 insertions(+)
>
> diff --git a/hw/arm/dyn_sysbus_devtree.c b/hw/arm/dyn_sysbus_devtree.c
> index 56af62f..ac34f07 100644
> --- a/hw/arm/dyn_sysbus_devtree.c
> +++ b/hw/arm/dyn_sysbus_devtree.c
> @@ -1,6 +1,139 @@
>   #include "hw/arm/dyn_sysbus_devtree.h"
>   #include "qemu/error-report.h"
>   #include "sysemu/device_tree.h"
> +#include "hw/vfio/vfio-platform.h"
> +
> +static void vfio_fdt_add_device_node(SysBusDevice *sbdev, void *opaque);
> +
> +static char *format_compat(char * compat)
> +{
> +    char *str_ptr, *corrected_compat;
> +    /*
> +     * process compatibility property string passed by end-user
> +     * replaces / by , and ; by NUL character
> +     */
> +    corrected_compat = g_strdup(compat);
> +    /*
> +     * the total length of the string has to include also the last
> +     * NUL char.
> +     */
> +
> +    str_ptr = corrected_compat;
> +    while ((str_ptr = strchr(str_ptr, '/')) != NULL) {
> +        *str_ptr = ',';
> +    }
> +
> +    /* substitute ";" with the NUL char */
> +    str_ptr = corrected_compat;
> +    while ((str_ptr = strchr(str_ptr, ';')) != NULL) {
> +        *str_ptr = '\0';
> +    }
> +
> +    return corrected_compat;
> +}
> +
> +static void wrap_vfio_fdt_add_node(SysBusDevice *sbdev, void *opaque)
> +{
> +    PlatformDevtreeData *data = opaque;
> +    VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
> +    VFIODevice *vbasedev = &vdev->vbasedev;
> +    gchar irq_number_prop[8];
> +    Object *obj = OBJECT(sbdev);
> +    char *corrected_compat;
> +    uint64_t irq_number;
> +    int compat_str_len = strlen(vdev->compat)+1;
> +    int i;
> +
> +    corrected_compat = format_compat(vdev->compat);
> +    snprintf(vdev->compat, compat_str_len, "%s", corrected_compat);
> +    g_free(corrected_compat);
> +
> +    vfio_fdt_add_device_node(sbdev, opaque);
> +
> +    for (i = 0; i < vbasedev->num_irqs; i++) {
> +        snprintf(irq_number_prop, sizeof(irq_number_prop), "irq[%d]", i);
> +        irq_number = object_property_get_int(obj, irq_number_prop, NULL)
> +                                                 + data->irq_start;
> +        /*
> +         * for setting irqfd up we must provide the virtual IRQ number
> +         * which is the sum of irq_start and actual platform bus irq
> +         * index. At realize point we do not have this info.
> +         */
> +        if (vdev->irqfd_allowed) {
> +            vfio_setup_irqfd(sbdev, i, irq_number);
> +        }
> +    }
> +}
> +
> +static void vfio_fdt_add_device_node(SysBusDevice *sbdev, void *opaque)
> +{
> +    PlatformDevtreeData *data = opaque;
> +    void *fdt = data->fdt;
> +    const char *parent_node = data->node;
> +    int compat_str_len;
> +    char *nodename;
> +    int i, ret;
> +    uint32_t *irq_attr;
> +    uint64_t *reg_attr;
> +    uint64_t mmio_base;
> +    uint64_t irq_number;
> +    gchar mmio_base_prop[8];
> +    gchar irq_number_prop[8];
> +    VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
> +    VFIODevice *vbasedev = &vdev->vbasedev;
> +    Object *obj = OBJECT(sbdev);
> +
> +    mmio_base = object_property_get_int(obj, "mmio[0]", NULL);
> +
> +    nodename = g_strdup_printf("%s/%s@%" PRIx64, parent_node,
> +                               vbasedev->name,
> +                               mmio_base);
> +
> +    qemu_fdt_add_subnode(fdt, nodename);
> +
> +    compat_str_len = strlen(vdev->compat) + 1;
> +    qemu_fdt_setprop(fdt, nodename, "compatible",
> +                            vdev->compat, compat_str_len);
> +
> +    reg_attr = g_new(uint64_t, vbasedev->num_regions*4);
> +
> +    for (i = 0; i < vbasedev->num_regions; i++) {
> +        snprintf(mmio_base_prop, sizeof(mmio_base_prop), "mmio[%d]", i);
> +        mmio_base = object_property_get_int(obj, mmio_base_prop, NULL);
> +        reg_attr[2*i] = 1;
> +        reg_attr[2*i+1] = mmio_base;
> +        reg_attr[2*i+2] = 1;
> +        reg_attr[2*i+3] = memory_region_size(&vdev->regions[i]->mem);
> +    }
> +
> +    ret = qemu_fdt_setprop_sized_cells_from_array(fdt, nodename, "reg",
> +                     vbasedev->num_regions*2, reg_attr);
> +    if (ret < 0) {
> +        error_report("could not set reg property of node %s", nodename);
> +    }
> +
> +    irq_attr = g_new(uint32_t, vbasedev->num_irqs*3);
> +
> +    for (i = 0; i < vbasedev->num_irqs; i++) {
> +        snprintf(irq_number_prop, sizeof(irq_number_prop), "irq[%d]", i);
> +        irq_number = object_property_get_int(obj, irq_number_prop, NULL)
> +                                                 + data->irq_start;
> +        irq_attr[3*i] = cpu_to_be32(0);
> +        irq_attr[3*i+1] = cpu_to_be32(irq_number);
> +        irq_attr[3*i+2] = cpu_to_be32(0x4);
> +    }
> +
> +   ret = qemu_fdt_setprop(fdt, nodename, "interrupts",
> +                     irq_attr, vbasedev->num_irqs*3*sizeof(uint32_t));
> +    if (ret < 0) {
> +        error_report("could not set interrupts property of node %s",
> +                     nodename);
> +    }
> +
> +    g_free(nodename);
> +    g_free(irq_attr);
> +    g_free(reg_attr);
> +}
>   
>   int sysbus_device_create_devtree(Object *obj, void *opaque)
>   {
> @@ -17,6 +150,11 @@ int sysbus_device_create_devtree(Object *obj, void *opaque)
>           return object_child_foreach(obj, sysbus_device_create_devtree, data);
>       }
>   
> +    if (object_dynamic_cast(obj, TYPE_VFIO_PLATFORM)) {

You should only ever check for specific VFIO device types. A generic 
"vfio-platform" device type will not work, since you won't have enough 
auxiliary information once devices become more complicated.


Alex