Re: [Qemu-devel] [PATCH v12 7/9] hw/arm/sysbus-fdt: enable vfio-calxeda-xgmac dynamic instantiation

[Vikram Sethi <vikrams@codeaurora.org>]

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Hi Eric,

On 03/19/15 12:16, Eric Auger wrote:
> This patch allows the instantiation of the vfio-calxeda-xgmac device
> from the QEMU command line (-device vfio-calxeda-xgmac,host="<device>").
>
> A specialized device tree node is created for the guest, containing
> compat, dma-coherent, reg and interrupts properties.
>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>
> ---
> v10 -> v11:
> - add dma-coherent property to calxeda midway xgmac node (fix)
> - use qemu_fdt_setprop to add reg property instead of
>   qemu_fdt_setprop_sized_cells_from_array
> - commit message rewording
>
> v8 -> v9:
> - properly free resources in case of errors in
>   add_calxeda_midway_xgmac_fdt_node
>
> v7 -> v8:
> - move the add_fdt_node_functions array declaration between the device
>   specific code and the generic code to avoid forward declarations of
>   decice specific functions
> - rename add_basic_vfio_fdt_node into
>   add_calxeda_midway_xgmac_fdt_node
>
> v6 -> v7:
> - compat string re-formatting removed since compat string is not exposed
>   anymore as a user option
> - VFIO IRQ kick-off removed from sysbus-fdt and moved to VFIO platform
>   device
> ---
>  hw/arm/sysbus-fdt.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 72 insertions(+)
>
> diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
> index 3038b94..6e465b2 100644
> --- a/hw/arm/sysbus-fdt.c
> +++ b/hw/arm/sysbus-fdt.c
> @@ -26,6 +26,8 @@
>  #include "sysemu/device_tree.h"
>  #include "hw/platform-bus.h"
>  #include "sysemu/sysemu.h"
> +#include "hw/vfio/vfio-platform.h"
> +#include "hw/vfio/vfio-calxeda-xgmac.h"
>  
>  /*
>   * internal struct that contains the information to create dynamic
> @@ -53,11 +55,81 @@ typedef struct NodeCreationPair {
>      int (*add_fdt_node_fn)(SysBusDevice *sbdev, void *opaque);
>  } NodeCreationPair;
>  
> +/* Device Specific Code */
> +
> +/**
> + * add_calxeda_midway_xgmac_fdt_node
> + *
> + * Generates a simple node with following properties:
> + * compatible string, regs, interrupts, dma-coherent
> + */
Since this function is applicable to any dma-coherent device with
only mmio and irq properties to be exposed, should it be named
something more generic so that it can be reused for other devices?
> +static int add_calxeda_midway_xgmac_fdt_node(SysBusDevice *sbdev, void *opaque)
> +{
> +    PlatformBusFDTData *data = opaque;
> +    PlatformBusDevice *pbus = data->pbus;
> +    void *fdt = data->fdt;
> +    const char *parent_node = data->pbus_node_name;
> +    int compat_str_len, i, ret = -1;
> +    char *nodename;
> +    uint32_t *irq_attr, *reg_attr;
> +    uint64_t mmio_base, irq_number;
> +    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);
> +
> +    qemu_fdt_setprop(fdt, nodename, "dma-coherent", "", 0);
> +
> +    reg_attr = g_new(uint32_t, vbasedev->num_regions*2);
> +    for (i = 0; i < vbasedev->num_regions; i++) {
> +        mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);
You are missing the cpu_to_be32 for mmio_base and size.
As a result, a 0x1000 size really gets encoded as 0x100000.
If you have a device with 2 MMIO regions, this results
in the second region getting a wrong starting address in
the guest kernel, which also doesn't match the 2nd stage
mapping done by KVM. With that fix, able to test this function
with a device with 2 regions as well.
> +        reg_attr[2*i] = (uint32_t)mmio_base;
> +        reg_attr[2*i+1] = (uint32_t)memory_region_size(&vdev->regions[i]->mem);
> +    }
> +    ret = qemu_fdt_setprop(fdt, nodename, "reg", reg_attr,
> +                           vbasedev->num_regions*2*sizeof(uint32_t));
> +    if (ret) {
> +        error_report("could not set reg property of node %s", nodename);
> +        goto fail_reg;
> +    }
> +
> +    irq_attr = g_new(uint32_t, vbasedev->num_irqs*3);
> +    for (i = 0; i < vbasedev->num_irqs; i++) {
> +        irq_number = platform_bus_get_irqn(pbus, sbdev , i)
> +                         + 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) {
> +        error_report("could not set interrupts property of node %s",
> +                     nodename);
> +    }
> +    g_free(irq_attr);
> +fail_reg:
> +    g_free(reg_attr);
> +    g_free(nodename);
> +    return ret;
> +}
> +
>  /* list of supported dynamic sysbus devices */
>  static const NodeCreationPair add_fdt_node_functions[] = {
> +    {TYPE_VFIO_CALXEDA_XGMAC, add_calxeda_midway_xgmac_fdt_node},
>      {"", NULL}, /* last element */
>  };
>  
> +/* Generic Code */
> +
>  /**
>   * add_fdt_node - add the device tree node of a dynamic sysbus device
>   *


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