Re: [Qemu-devel] [RESEND PATCH v16 1/6] hw/arm/sysbus-fdt: enable vfio-calxeda-xgmac dynamic instantiation

[Eric Auger <eric.auger@linaro.org>]

On 06/16/2015 10:29 AM, Peter Maydell wrote:
> On 15 June 2015 at 17:33, Eric Auger <eric.auger@linaro.org> 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>
>>
> 
> Minor nits:
> 
>> +/* Device Specific Code */
>> +
>> +/**
>> + * add_calxeda_midway_xgmac_fdt_node
>> + *
>> + * Generates a simple node with following properties:
>> + * compatible string, regs, interrupts, dma-coherent
>> + */
>> +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;
>> +
>> +    mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, 0);
>> +    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);
> 
> You should have spaces around the '*' operator here (and in a
> couple of other places below).
OK
> 
>> +    for (i = 0; i < vbasedev->num_regions; i++) {
>> +        mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);
>> +        reg_attr[2*i] = cpu_to_be32(mmio_base);
>> +        reg_attr[2*i+1] = cpu_to_be32(
>> +                                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);
> 
> In virt.c the magic numbers in cells 0 and 2 have #defines
> (GIC_FDT_IRQ_TYPE_SPI and GIC_FDT_IRQ_FLAGS_LEVEL_HI).
> 
> (1) maybe we should pull those out into a header so you can use them here
OK maybe I can put them in newly created include/hw/arm/virt.h
> (2) is this device really using a level-triggered interrupt?
yes it does
> 
>> +    }
>> +   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 */
>>  };
> 
> This file could get big if we have a lot of platform passthrough
> devices, but let's hope we don't...
Yes let's see how this feature gets used ;-)
> 
> Otherwise:
> Acked-by: Peter Maydell <peter.maydell@linaro.org>
If you allow me I will resend the patch file separately with the above
modifications.

Thanks!

Best Regards

Eric
> 
> -- PMM
>