Re: [PATCH v2 07/11] hw/arm/virt: add plug handler for TPM on SysBus

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 14 Jul 2023 00:09:23 -0700
Joelle van Dyne <j@getutm.app> wrote:

> TPM needs to know its own base address in order to generate its DSDT
> device entry.
> 
> Signed-off-by: Joelle van Dyne <j@getutm.app>
> ---
>  hw/arm/virt.c | 37 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 7d9dbc2663..432148ef47 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -2732,6 +2732,37 @@ static void virt_memory_plug(HotplugHandler *hotplug_dev,
>                           dev, &error_abort);
>  }
>  
> +#ifdef CONFIG_TPM

ifdefs are not really welcome, usually we use stubs instead
see stubs/virtio-md-pci.c or hw/display/acpi-vga-stub.c as an example.

> +static void virt_tpm_plug(VirtMachineState *vms, TPMIf *tpmif)
> +{
> +    PlatformBusDevice *pbus = PLATFORM_BUS_DEVICE(vms->platform_bus_dev);
> +    hwaddr pbus_base = vms->memmap[VIRT_PLATFORM_BUS].base;
> +    SysBusDevice *sbdev = SYS_BUS_DEVICE(tpmif);
> +    MemoryRegion *sbdev_mr;
> +    hwaddr tpm_base;
> +    uint64_t tpm_size;
> +
> +    if (!sbdev || !object_dynamic_cast(OBJECT(sbdev), TYPE_SYS_BUS_DEVICE)) {
it seems object_dynamic_cast() can deal with NULL object,  perhaps drop !sbdev part

> +        return;
> +    }
> +
> +    tpm_base = platform_bus_get_mmio_addr(pbus, sbdev, 0);
> +    assert(tpm_base != -1);
> +
> +    tpm_base += pbus_base;
> +
> +    sbdev_mr = sysbus_mmio_get_region(sbdev, 0);
> +    tpm_size = memory_region_size(sbdev_mr);
> +

> +    if (object_property_find(OBJECT(sbdev), "baseaddr")) {
> +        object_property_set_uint(OBJECT(sbdev), "baseaddr", tpm_base, NULL);
> +    }
> +    if (object_property_find(OBJECT(sbdev), "size")) {
> +        object_property_set_uint(OBJECT(sbdev), "size", tpm_size, NULL);
> +    }
why both properties wrapped into conditions?
Also can addr/size be wrong and cause property setter fail?
(if yes then you'd need to s/, NULL, &error_abort/)


> +}
> +#endif
> +
>  static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>                                              DeviceState *dev, Error **errp)
>  {
> @@ -2803,6 +2834,12 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
>          vms->virtio_iommu_bdf = pci_get_bdf(pdev);
>          create_virtio_iommu_dt_bindings(vms);
>      }
> +
> +#ifdef CONFIG_TPM
> +    if (object_dynamic_cast(OBJECT(dev), TYPE_TPM_IF)) {
> +        virt_tpm_plug(vms, TPM_IF(dev));
> +    }
> +#endif
>  }
>  
>  static void virt_dimm_unplug_request(HotplugHandler *hotplug_dev,